Pharm Final Study Guide
CHAPTER 2: PHARMACOLOGIC PRINCIPLES (10 Questions)
1. Define the common terms used in pharmacology (see Key Terms).
 Additive effect: effects of 2 or more drugs = sum of individual effect 1+1 = 2
 Adverse drug event: undesirable or failing occurrence in administer meds
 Adverse drug reaction: Any unexpected, unintended, undesired, or excessive response to
a medication given at therapeutic dosages (as opposed to overdose)
 Adverse effect: any undesirable effects that are a direct response to one or more drugs.
 A pharmacologic reaction is an extension of a drug’s normal effects in the body.
 Agonist: a drug that binds and stimulates the activity of 1 or more receptors
 Allergic reaction : An immunologic hypersensitivity reaction resulting from the unusual
sensitivity of a patient to a particular medication; a type of adverse drug event.
 Antagonist: a drug that binds and inhibits the activity of 1 or more receptors
 Antagonist effects: 1 + 1 < 2
 Bioavailability: measure of extent drug absorption (0% - 100%)
 Biotransformation: metabolism
 Blood-brain barrier: barrier system that restricts viruses or bacteria, (between
bloodstream and CNS)
 Contraindication: a reason for a patient not receiving treatment because of harmfulness
 Cytochrome P-450: class of enzymes in drug metabolism
 Dependence: physiologic or psychological needs for a drug to avoid physical withdrawal
 Tolerance: a decreasing response to a repeated drug dose
 Dissolution: process of solid form of drug -> soluble form before being absorbed
 Drug-induced teratogenesis: defects in the developing fetus cause by the toxicity effects
of drug
 First pass effect: metabolism in liver absorbed from GI tract before drug reaches
systemic circulation thru bloodstream
 G6PD: hereditary condition in which red blood cells break down
 P-glycoprotein: transporter protein that move drugs out of cell to gut, urine, bile
 Synergistic effects: 1+1 > 2
 Peak level
 Trough level
 Steady state: is the physiologic state in which the amount of drug removed via
elimination is equal to the amount of drug absorbed from each dose
 Drug incompatibilities: are physical and chemical reactions that occur in vitro between
two or more drugs when the solutions are combined in the same syringe, tubing, or bottle
2. Understand the general concepts such as pharmaceutics, pharmacokinetics, and
pharmacodynamics and their application in drug therapy and the nursing process.

Pharmaceutics: is the science of dosage form design. (work of a pharmacist)


Determines the rate at which drug dissolution and absorption occur.
Achieve therapeutic response with minimal adverse effect

Dosage form determines the rate at which drug dissolution and absorption
occur.
Dosage forms are designed to achieve a desired therapeutic response with
minimal adverse effects; many dosage forms were developed to encourage
patient adherence with the medication.


Pharmacokinetics: study of what body does to drugs
 Absorption
 Bioavailability
 The extent of drug absorption (the ability of a drug to be absorbed
by the body)
 First pass effect
 Large proportion of a drug is chemically changed into inactive
metabolites by the liver.
 Much smaller amount will be bioavailable.
 Distribution
 Transport of a drug by the bloodstream to its site of action
 Albumin is the most common blood protein and carries the majority of
protein-bound drug molecules
 Metabolism
 Also referred to as biotransformation
 Biochemical alteration of a drug into an inactive metabolite, a
more soluble compound, a more potent active metabolite (as in the
conversion of an inactive prodrug to its active form), or a less
active metabolite.
 Cytochrome P-450 enzymes (or simply P-450 enzymes), also
known as microsomal enzymes

Lipophilic: “fat loving”
 Hydrophilic: “water loving”
 Enzymes
 Excretion

Elimination of drugs from the body

Renal excretion (primary organ responsible for excretion)

Biliary excretion

Bowel excretion

Half-life: time required for half (50%) of a given drug to be
removed from the body

Measures the rate at which the drug is eliminated from the body



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After approximately five half-lives, most drugs are considered to
be effectively removed from the body.

Steady state : Physiologic state in which the amount of drug
removed via elimination is equal to the amount of drug absorbed
with each dose.
Pharmacodynamics: The study of what the drug does to the body (examines the effects of
drugs on the body), mechanism of drug action
 Receptor interaction: 5
 Active: producing response
 Inactive: blocking response
 Agonist: Drugs with complete attachment and response
 Antagonists: Drugs that attach but do not elicit a response
 Partial agonists: Drugs that attach and elicit a small response but
also block other responses




Enzyme (Selective) interaction
Relatively Selective Drugs: Drugs that exert a singular effect on a
specific target tissue or organ. The drug attracts the enzymes to bind
with the drug instead of allowing the enzymes to bind with their normal
target cells. As a result, the target cells are protected from the action of the
enzymes.
Ex: NSAIDs, such as aspirin and ibuprofen, target area where
inflammation is present
Nonselective interaction
Relatively Nonselective Drugs: Drugs that exert their effect across
many tissues or organs.
Ex: Atropine, a drug given to relax muscles in the digestive tract,
may also relax muscles in the eyes and in the respiratory tract.
Drug effect
The length of time until the onset and peak of action and the duration of action play an
important part in determining the peak level (highest blood level) and trough level
(lowest blood level) of a drug. If the peak blood level is too high, then drug toxicity may
occur.
Duration of action is the time during which drug concentration is sufficient to elicit a
therapeutic response.
Drugs that are bound to plasma proteins are characterized by longer duration of
action. Protein binding does not make renal excretion faster, does not speed up drug
metabolism, and does not cause the duration of action to be shorter.
Peak level: highest blood level of a drug
Trough level: lowest blood level of a drug
Toxicity: occurs if the peak blood level of the drug is too high

Therapeutic drug monitoring

Pharmacotherapeutics
- The clinical use of drugs to prevent and treat diseases
- Defines principles of drug actions—the cellular processes that change in response to
the presence of drug molecules
- Drugs are organized into pharmacologic classes
- Different drug dosage forms have different pharmaceutical properties.
- Dosage form determines drug dissolution rate.
- Contraindications: any condition or disease status that hampers a particular drug
therapy
The implementation of a treatment plan can involve several type of therapies:
- Acute therapy: involves more intensive drug treatment and implemented in the
acutely ill (those with rapid onset of illness)
Ex: intensive chemotherapy for a patient with newly diagnosed cancer
- Maintenance therapy: prevent progression of a disease or chronic condition
Ex: treatment of chronic illnesses such as hypertension, or use of oral
contraceptives for birth control.
- Supplemental (or replacement) therapy: supplies the body with a substances needed
to maintain normal function
Ex: administration of insulin to diabetic patients, or iron to patients with irondeficiency anemia
- Palliative therapy: provide patients with relief from symptoms, pain and stress
Ex: use of high-dose opioid analgesics to relieve pain in the final stages of cancer
- Supportive therapy: maintains the integrity of the body during illness or trauma
recovery
Ex: Administration of fluids, volume expanders, or blood products to a patient
who has lost blood during surgery.
- Prophylactic therapy: prevent illness or other undesirable outcome
Ex: use of preoperative antibiotic therapy for surgical procedures
- Empiric therapy: administer based on the patient’s initial presenting symptoms
Ex: use of antibiotics active against the organism most commonly associated with
a specific infection before the results of the culture and sensitivity reports are available
Monitoring:
- Therapeutic response
- Adverse effects
- Toxic effects
- Therapeutic index: ratio of drug’s toxic level : benefit of drug
the larger the therapeutic index, the safer the drug is
- Drug concentration
- Patient condition

Tolerance: decreasing response to repeated drug doses

Dependence: physiologic or psychological need for a drug

Physical dependence: physiologic need for a drug to avoid physical withdrawal
symptoms

Psychological dependence: also known as addiction and is the obsessive desire for the
euphoric effects of a drug

Drug interactions
a.
Additive effects 1+1 = 2
b.
Synergistic effects 1+1 > 2

c.
Antagonistic Incompatibility 1+ 1< 2
Adverse drug event (ADE)

Adverse drug withdrawal event

6 rights

Medication use process in which errors can occur:
a.
Procuring
b.
Prescribing
c.
Dispensing
d.
Administering
e.
Monitoring

Adverse drug reactions:
.
Pharmacologic reaction: is an extension of drug’s normal effects in the body
a.
Hypersensitivity (allergic) reaction: immunologic hypersensitivity
b.
Idiosyncratic reaction: adverse effects that cannot be explained by the known
mechanisms of action of the offending agent
c.
Drug interaction

Other drug effects
.
Teratogenic: any agent that causes an abnormality following fetal exposure during
pregnancy
a.
Mutagenic: Anything that causes a mutation (a change in the DNA of a cell). DNA
changes caused by mutagens may harm cells and cause certain diseases, such as cancer.
b.
Carcinogenic effects: an agent with the capacity to cause cancer in humans


Pharmacognosy
Four main sources for drugs:
i. Plants
ii. Animals
iii. Minerals
iv. Laboratory synthesis
3. Pharmacoeconomics
 Cost-benefit analysis
 Examine treatment outcomes in relation to the comparative total costs of treatment with
drug(s)
4.
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
Toxicology
Science of adverse effects of chemicals on living organisms
Clinical toxicology: Care specifically to the poisoned patient
Poison Control Centers
Treatment based on system of priorities
 ABCs
 Prevent absorption of the toxic substance and/or speed its elimination from the
body
5.
Demonstrate an understanding of the various drug dosage forms as related to drug
therapy and the nursing process.
Fastest to slowest absorption:
 Oral disintegration, buccal tablets, and oral soluble wafers
 Liquids, elixirs, and syrups
 Suspension solutions
 Powders
 Capsules
 Tablets
 Coated tablets
 Enteric-coated tablets (broken down not in stomach but in intestines)
6. Discuss the relevance of the four aspects of pharmacokinetics (absorption,
distribution, metabolism, excretion) to professional nursing practice as related to drug
therapy for a variety of patients and health care settings.
 Absorption: when the drug is released from the formulation//administration site and
enters the bloodstream
 Distribution: the movement once it is in the bloodstream
 Metabolism: the body using the drug and giving off a byproduct
 Excretion: getting rid of the by product
7. Discuss the use of natural drug sources in the development of new drugs.
medicinal drugs derived from natural plants and animals
8. Develop a nursing care plan that takes into account general pharmacological
principles, specifically pharmacokinetic principles, as they relate to the nursing process.
 Pharmacokinetic: The study of the activity and interaction of meds with the body (what
the body does to the drug)
 The mechanism of drug actions in living tissues
 Therapeutic effect
 Mechanism of action
 Drug–receptor relationships
 Enzymes (selective interaction)
 Nonselective Interactions
9. Enteral Route: The drug is absorbed into the systemic circulation through the oral or
gastric mucosa or the small intestine. Reduced blood flow to the stomach and the presence of
food in the stomach apply to enteral drugs
 Oral
 Sublingual
 Buccal

Rectal (can also be topical)
10. Parenteral Route: Parenteral routes result in the fastest absorption and therefore also the
fastest effects.
 Intravenous (fastest delivery into the blood circulation)
 Intramuscular
 Subcutaneous
 Intradermal
 Intraarterial
 Intrathecal
 Intra articular crosses the joint surface
11. Topical Route
 Skin (including transdermal patches)
 Eyes
 Ears
 Nose
 Lungs (inhalation)
 Rectal
 Vagina
Why should you not crush sustained-release tablets?
→ Do not crush or break SRT or enteric-coated tablets. Crushing SRT will cause the patient to
receive all the drug at one time leading to severe adverse effects and possible overdose. Crushing
an enteric coated med will cause the medication to be absorbed in the stomach rather than the
intestine
CHAPTER 3: LIFESPAN CONSIDERATIONS (10 QUESTIONS)

Special considerations:

Pregnancy

Newborn

Pediatric

Older adult
1. Pregnancy:
 The first trimester of pregnancy is generally the greatest danger of drug-induced
developmental defects.
 Drug transfer to the fetus occurs in the last trimester (transfer drugs + nutrients by
diffusion across the placenta). Drug transfer to the fetus is more likely during
the last trimester as a result of enhanced blood flow to the fetus.
 Exposure of drug to fetus is detrimental during the first trimester
 Pregnant women need to take medications to control illness such as high blood
pressure
 Active transport: requires energy, substance from lower to higher concentration.
 Passive transport (diffusion): does not require energy, substance from higher to
lower concentration.
 The primary drug characteristics that increase the likelihood drug transfer via
breastfeeding
 Fat solubility
 Low molecular weight
 High concentration
What is a category A drug?
·
Studies indicate no risk to the fetus
What is a category B drug?
·
No risk to animal fetus, information for humans not available
What is a category C drug?
·
Adverse effects reported in the animal fetus, information on humans not available
What is a category D drug?
· Possible fetus risk in humans has been reported, potential benefits vs risk may warrant
treatment in someone who is pregnant
What is a category X drug?
·
Fetal abnormalities have been reported. These drugs are not to be used in pregnant women.
2.
Newborn:
 Neonate: birth to 1 month
 Infant: 1-12 months
 Child: 1-12 years old
Characteristics of pediatric patients: to administer medications to pediatric
patients accurately, nurses must take into account organ maturity, body surface
area, age, and weight.
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Absorption
Skin is thinner, and more permeable
Stomach lacks acid to kill bacteria
Lungs have weaker mucous barriers
Body temperature is less well regulated, and dehydration occurs easily
Liver and kidneys are immature, and therefore drug metabolism and
excretion are impaired.
Total body water content is greater in children than in adults
-Gastric pH is less acidic because acid-producing cells in the stomach are
immature until approximately 1 to 2 years of age.
-Gastric emptying is slowed because of slow or irregular peristalsis.
-First-pass elimination by the liver is reduced because of the immaturity of
the liver and reduced levels of microsomal enzymes.
-Intramuscular absorption is faster and irregular.
Distribution -Fat content is lower in young patients because of greater total body water.
-Protein binding is decreased because of decreased production of protein by
the immature liver.
-More drugs enter the brain because of an immature blood-brain barrier.
Metabolism -Levels of microsomal enzymes are decreased because the immature liver
has not yet started producing enough.
Excretion
3.
-Glomerular filtration rate and tubular secretion and resorption are all
decreased in young patients because of kidney immaturity.
-Perfusion to the kidneys may be decreased, which results in reduced renal
function, concentrating ability, and excretion of drugs
Older Adult:
Absorption
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gastric pH less acidic, alter absorption
gastric emptying slowed
movement thru GI tract slowed b/c of decrease muscle tone and activity
blood flow to GI tract decrease
absorptive surface of GI tract reduced
Distribution
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
lower total body water mean greater fat content
decrease production of protein by the liver, resulting in decreased
protein binding of drugs (and liver increase circulation of free drugs)
Metabolism

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
the level of microsomal enzymes are decreased b/c the capacity of the
aging liver to produce them is reduced
Blood flow to the liver is reduced
decrease metabolism leads to potential for drug toxicity


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decrease glomerular filtration rate
decrease number of nephrons
drugs are cleared less effectively b/c of decrease excretion
Excretion


Polypharmacy: The use of many different drugs concurrently in treating a
patient who often has several health problem
As a general rule, dosing for the older adult should follow the admonition “Start
low and go low”, which means to start with the lowest possible dose (often less
than an average adult dose) and increase the dose slowly, based on a patient
response.
Problematic medications for the older adult: common complication
Opioids: respiratory depression (primary), confusion, constipation, urinary retention, nausea,
vomiting, , falls
NSAIDs: Edema, nausea, gastric ulceration, bleeding, renal toxicity
Anticoagulants (heparin and warfarin): Major and minor bleeding episodes, many drug
interactions, dietary interactions
Anticholinergics: Blurred vision, constipation, confusion, dry mouth, urinary retention,
tachycardia
Antidepressant: Sedation and strong anticholinergic adverse effects
Antihypertensives: Nausea, hypotension, diarrhea, bradycardia, heart failure, impotence
Cardiac glycosides (digoxin): Visual disorders, nausea, diarrhea, dysrhythmias, hallucinations,
decreased appetite, weight loss
CNS depressants (muscle relaxants and opioids): Sedation, weakness, dry mouth, confusion,
urinary retention, ataxia
Sedatives and hypnotics: Confusion, daytime sedations, ataxia, lethargy, increased risk for falls
Thiazide diuretics: Electrolyte imbalance, rashes, fatigue, leg cramps, dehydration
Conditions require special caution and monitoring in older adult patients
bladder flow obstruction condition: Anticholinergics, antihistamines, decongestants,
antidepressants
clotting disorder: NSAIDs, aspirin, antiplatelet drugs
chronic constipation: Calcium channel blockers, tricyclic antidepressants, anticholinergics
chronic obstructive pulmonary disease: Long-acting sedatives or hypnotics, narcotics, beta
blockers
heart failure and hypertension: Sodium, decongestants, amphetamines, over-the-counter cold
products
insomnia: Decongestants, bronchodilators, monoamine oxidase inhibitors
Parkinson’s Disease: Antipsychotics, phenothiazines
syncope and falls: Sedatives, hypnotics, opioids, CNS depressants, muscle relaxants,
antidepressants, antihypertensives
Chapter 26: Coagulation Modifier Drugs (8 Questions)
1. Briefly review the coagulation process and the impact of coagulation modifiers, including
anticoagulants, antiplatelets, thrombolytics, and antifibrinolytics.
- Coagulation modifiers have a variety of uses
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(1) prevention or elimination of clotting in a peripherally inserted catheter,
(2) maintenance of patency (without clotting) of central venous catheters,
(3) clot prevention in coronary artery bypass grafting,
(4) prevention of clotting after major vessel injury
(5) treatment of thrombophlebitis to prevent venous and/or arterial thromboembolism,
(6) prevention of clotting with use of prosthetics (e.g., heart valve replacements) and in
atrial fibrillation.
- Coagulation modifier drugs aid the body in reversing or achieving hemostasis, and they can be
broken down into several main categories

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Anticoagulants – inhibit the action or formation of clotting factors and therefore prevent
clots from forming (prevent the formation of a clot; they DO NOT break down a clot)
Antiplatelet drugs – prevent platelet plugs from forming by inhibiting platelet
aggregation, which can be beneficial in preventing heart attacks and strokes
Hemorheologic drugs – alter platelet function without preventing the platelets from
working
Thrombolytic drugs – lyse (break down) clots or thrombi that have already formed
Antifibrinolytic drugs (hemostatic drugs) – promote blood coagulation
2. Compare the mechanisms of action, indications, cautions, contraindications, drug
interactions, adverse effects, routes of administration, and dosages of the various
anticoagulants, antiplatelets, thrombolytics, and antifibrinolytics.
I.
Anticoagulants:
Anticoagulants
Mechanism of Action
Indications
Adverse Effect
_ Anticoagulants are also called
antithrombotic drugs because they
work to prevent the formation of a
clot or thrombus, a condition
known as thrombosis.
_ Prevention of clot
formation also prevents
Embolus: stroke, MI, DVT,
PE.
 If it lodges in a
coronary artery, it
causes a MI.
 If it obstructs a
brain vessel, it
causes a stroke.
_ Bleeding
 Risk increase with
increased dosages
 May be localized
(hematoma at site
of injection) or
systemic
_ All anticoagulants work in the
clotting cascade but do so at
different points.
_Heparin-induced
thrombocytopenia (HIT)

_ Have NO direct effect on a
blood clot that is already formed
(Does NOT lyse existing clots)
If it goes to the
lungs, it is a
pulmonary
embolism.
_Thrombus: a blood clot
 If it goes to a vein in
_ Embolus: a thrombus moves thru
the leg, it is a deep
blood vessels
vein thrombosis
_ Fibrin: The result is a large
(DVT).
concentration of a clot-forming
⇒ Collectively, these
substance
complications are called
_ Plasmin: Break down fibrin,
thromboembolic events.
keep thrombus localize, & prevent _ Unstable angina
it becomes embolus
_ Atrial fibrillation
_ Indwelling devices
(mechanical heart valves)
_ Major orthopedic surgery
Contraindications
_ KDA
_ Any acute bleeding process or
high risk for such an occurrence.
_ Other anticoagulants are rated in
lower pregnancy categories (B or
C).
_No anticoagulants with spinal
epidural catheter
Toxicity
Managing Overdose
_ S/S: hematuria, melena
(blood in the stool),
petechiae, ecchymoses,
gum/mucous membrane
bleeding
→ in the event of bleeding,
the drug is to be stopped
immediately
_ In severe cases of toxicity:
IV injection of protamine
sulfate is indicated
Prevent Clot Formation
Anticoagulants
Drug Class
Inhibit clotting factors IIa (thrombin)
and Xa
Heparins
_Nausea, vomiting,
abdominal cramps,
thrombocytopenia
_ Importance of regular
lab testing
_ Signs of abnormal
bleeding
_ Measures to prevent
bruising, bleeding, or
tissue injury
_ Wearing a medical alert
bracelet
_ Do not increase foods
high in vitamin K
(tomatoes, dark leafy
green vegetables)
_ Consulting physician
before taking other meds
or OTC products,
including herbals
Individual Drugs
_ Unfractionated heparin:
“Heparin”
_ Low Molecular Weight
Heparins (LMWHs)


Enoxaparin (Lovenox)
Dalteparin (Pradaxa)
Inhibit Vitamin K-dependent clotting
factors II, VII, IX, and X
Coumarins
_ Warfarin (Coumadin)
*Antidote: Vitamin K
Inhibit factors IIa (thrombin)
Direct thrombin
inhibitors
_ Human antithrombin III
(Thrombate)
_ Lepirudin (Refludan)
_ Argatroban (Argatroban)
_ Bivalirudin (Angiomax)
_ Dabigatran (Pradaxa)
Inhibit factor Xa
Selective factor
Xa
inhibitor
_ Apixaban (Eliquis)
_ Rivaroxaban (Xarelto)
_ Fondaparinux (Arixtra)
_ Edoxaban (Savaysa)
_ Betrixaban (Bevyxxa)
AntiCoag: Inhibit clotting factors IIa (thrombin) and Xa
Heparin
_ Commonly used for DVT prophylaxis in a dose of 5000 units two or three times a day when
given subQ and does not need to be monitored when used prophylactically.
_ SubQ injection - Inject the medication without aspirating for blood return.
_ Therapeutic (for treatment) Heparin is given by continuous IV infusion and is weight-based
 Accurate record of patients weight.
 Check Kg, not lbs
 Monitor aPTT (usually q6h until therapeutic effects are seen)
 Normal range PTT: 46-70
_ Heparin and warfarin is sometimes combined with IV heparin therapy (overlap therapy)
→ Heparin is used to start to allow time for the blood levels of warfarin to reach adequate
levels.
Adverse Effects Bleeding, hematoma, anemia, thrombocytopenia
Heparin-induced thrombocytopenia (HIT)
_ Type I HIT
 Gradual reduction in platelets
 Heparin therapy can generally be continued
_ Type II HIT
 More than 50% reduction from baseline in the number of platelets
 Heparin therapy must be discontinued
*Treatment for HIT: the direct thrombin inhibitors lepirudin and
argatroban are both specifically indicated treatments
Interactions
_ NSAIDs (Aspirin), Oral anticoagulants, antiplatelet drugs, thrombolytics
Toxicity
_ Symptoms: hematuria, melena, petechiae, ecchymoses, and gum or
mucous membrane bleeding
_ Treatment: ANTIDOTE—IV protamine sulfate - 1 mg of protamine
can reverse the effects of 100 units of heparin
_ Intervention: STOP drug immediately
Nursing
Management
_ Intravenous doses (double-checked with another RN)
_Ensure that SC doses are given SC, not IM
_ SC doses should be given in areas of deep subcutaneous fat, and sites
rotated
_ Do not give SC doses within 2 inches of:
 The umbilicus, abdominal incisions, or open wounds, scars,
drainage tubes, stomas
_ Do not aspirate SC injections or massage injection site
 May cause hematoma formation
_ IV doses may be given by bolus or IV infusions
_ Anticoagulant effects seen immediately
Low Molecular Weight Heparins (LMWHs) - SubQ form
_ Enoxaparin (Lovenox) & Dalteparin (Fragmin)
_ Synthetic smaller molecular structure
_ More predictable anticoagulant response
_ Do not need lab monitoring of bleeding times using test (such as aPTT)
_ Given subcutaneously; Do NOT rub after administration
Contraindication _ Pts with an indwelling epidural catheter
⇒Can be given 2 hrs after epidural is removed as they have been
associated with epidural hematomas.
Nursing
Management
_ Given ONLY subcutaneously in the abdomen (not in the thigh, not IV)
_ Rotate injection sites
_ Protamine sulfate can be given as an antidote in case of excessive
anticoagulation
_Assess Hgb and Hct (not PTT or PT)
AntiCoag: Inhibit Vitamin K-dependent clotting factors II, VII, IX, and X
Warfarin Sodium (Coumadin)
_ Fun fact—rat poison
 Most commonly prescribed oral anticoagulant
 Requires careful monitoring of the PT/INR ratio (a standardized measure of the
degree to which a patient’s blood coagulability has been reduced by the drug)
 A normal INR (without warfarin) is 1.0
 Therapeutic INR (with warfarin) ranges from 2 to 3.5
 Variations in certain genes, CYP2CP and VKORC1
 Foods high in vitamin K may reduce warfarin’s ability to prevent clots
→ Avoid—leafy green vegetables: kale, spinach, collard greens
 Final effect is prevention of clot formation
Adverse Effects
Contraindications
_ Bleeding, lethargy, muscle pain, “purple toes”
_ Strongly contraindicated in pregnancy.
_ Acetaminophen, Amiodarone, NSAIDs (Aspirin)
_ Herbal: St. John’s wort, Dong Quai, Garlic, Ginger, Gingko, Ginseng
Interactions
_ Symptoms: hematuria, melena, petechiae, ecchymoses, and gum or
mucous membrane bleeding
_ Treatment: ANTIDOTE—Vitamin K is given - if bleeding is
severe may transfuse plasma or clotting factors
_ Intervention: DISCONTINUE drug immediately
Toxicity
Nursing
Management
_ May be started while the patient is still on heparin until PT-INR
levels indicate adequate anticoagulation
_ Full therapeutic effect takes several days
_ Monitor PT-INR regularly—keep follow-up appointments
Drugs
(HIGH
ALERT)
Description
Argatroban
_ Is a synthetic direct thrombin inhibitor.
_ Indication: both for treatment of active HIT and for percutaneous coronary
intervention procedures in patients at risk for heparin-induced
thrombocytopenia (i.e., those with a history of the disorder).
_ It is given only by the IV route.
_ A lower dosage must be used in patients with severe hepatic dysfunction.
Dabigatran
_ Is the first oral direct thrombin inhibitor.
_ Indication: prevention of strokes and thrombosis in patients with
nonvalvular atrial fibrillation.
_ Dabigatran is a prodrug that becomes activated in the liver.
_ The dose of dabigatran is reduced in patients with decreased renal function.
_ A/E: bleeding, with increased GI bleeding as compared with warfarin.
_ No coagulation monitoring is required for dabigatran.
_ Interacts: phenytoin, carbamazepine, rifampin, and St. John’s wort (which
cause a decreased effect) and strong CYP3A4 inhibitors such as amiodarone,
quinidine, erythromycin, verapamil, azole antifungals, and HIV protease
inhibitors (which cause an increased effect). Other anticoagulants are not to
be given with dabigatran.
_ Idarucizumab (Praxbind) is a specific dabigatran antidote that reverses
the anticoagulant effects of dabigatran for emergency surgery or in lifethreatening or uncontrolled bleeding.
Enoxaparin
_ Is the prototypical LMWH
_ Higher degree of bioavailability and a longer elimination half-life than
unfractionated heparin.
_ Laboratory monitoring is not necessary
_ It is available only in injectable form
_ Indication:
 Used after major orthopedic surgery (Prevent DVT)
 Prophylaxis and treatment
 Used with oral warfarin as overlap treatment for pulmonary
embolism or DVT
_ Heparin + Enoxaparin = DEADLY
_ BBW: potential spinal hematomas if the patient has an epidural catheter
Fondaparinux
(New Drug)
no risk for
HIT
_ Is a selective inhibitor of factor Xa
_ Indication: prophylaxis or treatment of DVT or PE.
_ Contraindication: patients with a creatinine clearance less than 30
mL/min or a body weight of less than 50 kg.
_ A/E:
 Bleeding is the most common and serious adverse reaction.
 Thrombocytopenia
_ Therapy should be stopped if platelet count falls below 100,000 platelets
per microliter.
_ It should not be given for at least 6 to 8 hours after surgery and should be
used with caution in conjunction with warfarin.
_ There is no antidote
_ BBW: potential spinal hematomas if the patient has an epidural catheter.
Heparin
Rivaroxaban
(Table above)
_ Is the first oral factor Xa inhibitor.
_ Indication: prevention of strokes in patients with nonvalvular atrial
fibrillation, postoperative thromboprophylaxis with knee and hip
replacement surgery, and treatment of DVT and PE.
_ Contraindications: active bleeding.
_ A/E: peripheral edema, dizziness, headache, bruising, diarrhea, hematuria,
and bleeding
_ BBW: potential spinal hematomas if the patient has an epidural catheter
and regarding the risk for thrombosis if these drugs are discontinued
abruptly.
_ Interacts: phenytoin, carbamazepine, rifampin, and St. John’s wort. An
increased effect is seen
with strong CYP3A4 inhibitors (amiodarone, erythromycin, ketoconazole,
HIV drugs, diltiazem, verapamil) and grapefruit juice. Apixaban (Eliquis),
edoxaban (Savaysa), and betrixaban (Bevyxxa) are similar drugs with similar
drug interactions and side effects.
_ No routine monitoring is required.
*Antidote: Andexxa
(Table above)
Warfarin
II.
Antiplatelet:
Antiplatelet
MOA
_ Aspirin, Clopidorel, Glycoprotein IIb/IIIa Inhibitors.
_ Antiplatelet drugs work to prevent platelet adhesion at the site of blood
vessel injury, which occurs before the clotting cascade
Indications
_ Antithrombotic Effects:
 Reduce risk of fatal and nonfatal strokes
 Acute unstable angina and MI
_ Aspirin – stroke
_ Clopidogrel – reduce the risk of thrombotic stroke, and for prophylaxis
against TIAs, post-MI prevention of thrombosis
_ Prevent clot formation by preventing platelet involvement in clot
formation.
Adverse Effects
Interactions
(Table below)
_ NSAIDs (Aspirin), Rifampin, Warfarin, heparin, thrombolytics
_Herbal: garlic, ginkgo, kava
Contraindication _ Thrombocytopenia (low blood platelet), active bleeding, leukemia,
traumatic injury, GI ulcer, vitamin K deficiency, and recent stroke.
Nursing
Management
_ Concerns and teaching tips same as for anticoagulants
 Dipyridamole: should be taken on an empty stomach
_ Check for drug-drug interactions
_ Monitoring for abnormal bleeding
Drugs
Description
Aspirin
_ Indication: recommended to prevent platelet aggregation for stroke
prevention by the American Stroke Society.
_ A/E:
 Flu-like symptoms in children and teenagers, Reye’s syndrome
 D/D, N/V, confusion, flushing, GI bleeding, thrombocytopenia,
agranulocytosis, leukopenia, neutropenia, hemolytic anemia,
bleeding
_ Contraindication: not to be used in children and teenagers, in patients
with any bleeding disorder, in pregnant or lactating women, or in patients
with vitamin K deficiency or peptic ulcer disease.
_A combination form of aspirin and dipyridamole (Aggrenox) is used for
antiplatelet purposes.
Clopidogrel
_ Indication:
 Reduce the risk for thrombotic stroke
 Prophylaxis against transient ischemic attacks (TIAs)
 Post-MI prevention of thrombosis
_ A/E: Chest pain, edema, flu like symptoms, headache, dizziness, fatigue,
abdominal pain, diarrhea, nausea Epistaxis, rash, and pruritus (itching)
_ BBW: certain genetic abnormalities, who may have a higher rate of
cardiovascular events due to reduced conversion to its active metabolite.
_ Interacts: amiodarone, CCBs, NSAIDs, and proton pump inhibitors.
The GP IIb/IIIa _ Eptifibatide (Integrilin), tirofiban (Aggrastat), and abciximab
(ReoPro)
inhibitors
_ Indication:
 Treat acute unstable angina and MI
 Treat angio-plasty (prevent the formation of thrombi. This is known
as thrombus prevention.)
_ A/E: Bradycardia, hypotension, edema, dizziness, bleeding,
thrombocytopenia
III.
Thrombolytic:
Thrombolytic
MOA
_Alteplase (Activase, Cathflo Activase), Tenecteplase (TNKase)
_Thrombolytic drugs work by mimicking the body’s own process of clot
destruction. Thrombolytics activate the conversion of plasminogen to
plasmin, which breaks down or lyses the thrombus → reestablishing
blood flow to the heart muscle via the coronary arteries and preventing
tissue destruction

Indications
Adverse Effects
Interactions
Plasmin is a proteolytic enzyme – it breaks down proteins.
Essentially, the substances that form clots are destroyed by
plasmin
Acute MI, Arterial thrombosis, DVT, Occlusion of shunts/catheters,
Pulmonary embolism, Acute ischemic stroke
_ Internal, intracranial, and superficial bleeding
_ Nausea, vomiting, hypotension, anaphylactoid reactions
_ Cardiac dysrhythmias; can be dangerous
_ anticoagulants, antiplatelet agents, or other drugs that affect platelet
function.
Contraindication _ preservatives, and concurrent use of other drugs that alter clotting.
Nursing
Management
_ Assess for a history of hypotension and cardiac dysrhythmias.
_ Follow strict manufacturer’s guidelines for preparation and
administration
_ Monitor IV sites for bleeding, redness, pain
_ Monitor for bleeding from gums, mucous membranes, nose, injection
sites
_ Observe for signs of internal bleeding (serious)
 Decreased BP (hypotension)
 Restlessness
 Increased pulse rate
 Decreased level of consciousness
Drugs
Alteplase
(high
alert)
IV.
Description
_ Indication: treat ischemic stroke
_ Available t-Pa made through recombinant DNA techniques.
_ It is fibrin specific and therefore does not produce a systemic lytic state.
_ Administration for therapeutic use does not induce an antigen-antibody
reaction.
_ It is present in the human body in a natural state. Therefore it can be
readministered immediately in the event of reinfarction.
_ t-Pa has a very short half-life of 5 minutes.
_ It is given with heparin to prevent reocclusion of the affected blood vessel.
Antifibrinolytic:
Antifibrinolytic
MOA
Indications
Adverse Effects
Interactions
Contraindication
Nursing
Management
Drugs
_ Aminocaproic acid (Amicar), Desmopressin (DDAVP), &
Tranexamic acid
_Prevent the lysis of fibrin → promoting clot formation
 Fibrin – The result is a large concentration of a clot-forming
substance
_ Used for prevention and treatment of excessive bleeding resulting
from hyperfibrinolysis or surgical complications
_ Treatment of hemophilia or von Willebrand’s disease
_ Prevent the lysis of fibrin, thus promoting clot formation
_ Antifibrinolytics have an effect opposite to that of the anticoagulants
_ Uncommon and mild
_ Rare reports of thrombotic events
_ Others include: Dysrhythmia, orthostatic hypotension, bradycardia,
headache, dizziness, fatigue, nausea, vomiting, abdominal cramps,
diarrhea
_ Estrogens or oral contraceptives
_ Disseminated intravascular coagulation
_ There are additional concerns for patients with dysrhythmias,
hypotension, bradycardia, convulsive disorders, nausea, vomiting, and
abdominal pain or diarrhea.
Description
Aminocaproic
acid (Amicar)
_ Indication: prevent and control the excessive bleeding that can result
from surgery or overactivity of the fibrinolytic system
Desmopressin
(DDAVP)
_ Indication:
 Increase the resorption of water by the collecting ducts in the
kidneys to prevent or control polydipsia, polyuria, dehydration in
patients with diabetes, and causes a dose-dependent increase in
plasma.
 it is often used to stop bleeding
 Desmopressin nasal spray is used for primary nocturnal enuresis.
_ Contraindication: hypersensitivity to it and in those with nephrogenic
diabetes insipidus.
Tranexamic acid
_ Indication: inhibition of fibrinolysis. It is administered intravenously
prior to surgery.
_ Contraindication: hypersensitivity and in patients with a history of
active thromboembolic disease and with concurrent use of combination
hormonal contraceptives.
5. Compare the laboratory tests used in conjunction with treatment with the various
coagulation modifiers and their implications for the therapeutic use of these drugs and the
monitoring for adverse reactions.
6. Develop a nursing care plan that includes all phases of the nursing process for patients
receiving anticoagulants, antiplatelets, thrombolytics, and antifibrinolytics.
•
Perform a thorough patient assessment to identify the presence of risk factors.
•
The use of Homan's sign is not recommended for assessment/evaluation of DVT of the
leg due to its lack of reliability.
•
It is also important to assess the skin, oral mucous membranes, gums, urine, and stool
for any evidence of bleeding. Assess patients for any blood in the urine or stool, easy bruising,
excessive bleeding from tooth brushing or shaving, or unexplained nosebleeds while receiving
these medications, and report any such findings.
•
Early signs of drug overdose for any of the clotting-altering drugs (i.e.,
anticoagulants) include bleeding of the gums during toothbrushing, unexplained nosebleeds or
bruising, and heavier-than-usual menstrual bleeding.
•
With the oral anticoagulants, rivaroxaban, apixaban, edoxaban, betrixaban, and
dabigatran, it is important—to patient safety—to be aware of their black box warnings related
to the concern for increased clotting with premature discontinuation
Chapter 29: Fluids and Electrolytes
1. Review the function of fluid volume and compartments within the body and the role
of each of the major electrolytes in maintaining homeostasis.
•Approximately 60% of the adult human body is water, distributed in the following
proportions: intracellular fluid 67%; interstitial fluid 25%; and plasma volume 8%.
•Total body water (TBW) is divided into intracellular and extracellular compartments.
Fluid volume outside the cells is either in the plasma or between the tissues, cells, or
organs.
•Intravascular fluid describes the fluid inside the blood vessels, and extravascular fluid
refers to the fluid outside the blood vessels.
-˜Intravascular fluid (Fluid inside blood vessels)
-˜Extravascular fluid (Fluid outside blood vessels)
•Lymph, cerebrospinal fluid
2.
Identify the various electrolytes, and give normal serum values for each
-Plasma or serum is the fluid that flows through the blood vessels (intravascular fluid).
The interstitial fluid (ISF) is the fluid that is in the space between cells, tissues, and
organs.
-There is one big difference between the plasma and the ISF. Plasma has a protein
concentration (primarily albumin) four times greater than that of the ISF. Protein solutes
have a large molecular weight, making them too large to pass through the walls of blood
vessels.
-Protein in the vessels exerts a constant osmotic pressure that prevents the leakage of too
much plasma through the capillaries into the tissues. This is called colloid oncotic
pressure and normally it is 24 mm Hg. The opposing pressure exerted by the interstitial
fluid is called hydrostatic pressure and normally it is 17 mm Hg—less than the colloid
oncotic pressure.
-Dehydration leads to a disturbance in the balance between the amount of fluid in the
extracellular compartment and that in the intracellular compartment. Dehydration may be
hypotonic, resulting from the loss of salt; hypertonic, resulting from fever with
perspiration; or isotonic, resulting from diarrhea or vomiting. Each form of dehydration is
treated differently. Carefully assess intake and output as well as skin turgor, urine
specific gravity, and blood levels of potassium, sodium, and chloride.
3.
briefly discuss the various fluid and electrolyte disorders that commonly occur in
the body with attention to fluid volume and/or electrolyte deficits and excesses.
Crystalloids
Mode of Action
Indication
Treat for dehydrated
patient who has:
-Better for treating
dehydration rather than
expanding PV
-Acute liver failure
-Used as maintenance fluids
to:




Compensate for
insensible fluid
losses
Replace fluids
Manage specific
fluid and electrolyte
disturbances
Promote urinary
flow
Contraindication
-known drug allergy to a specific
product and hypervolemia
-Severe electrolyte disturbance,
depending on the type of crystalloid
used.
-Acute nephrosis
-Adult distress
syndrome
-Burns
-Cardiopulmonary
bypass
-Hypoproteinemia
-Renal dialysis
-Reduction of the risk
for deep vein
thrombosis
-Shock
Adverse effects
Concentration
-May cause edema, especially peripheral or pulmonary
-May dilute plasma proteins, reducing COP
-0.9%: physiologically normal
concentration of sodium chloride
(isotonic), and it is referred to as NS
-Effects may be short-lived
-0.45% (“half-normal”)
-Prolonged infusions may worsen alkalosis or acidosis
-0.25% (“quarter-normal”)
-3% (hypertonic saline)
-5% (hypertonic saline)
Colloid Oncotic (Protein substances)
Mechanism of action
Increase colloids osmotic pressure
(COP) → move fluid from interstitial
compartment to
plasma compartment
-Colloids increase the blood volume
and are sometimes called plasma
expanders.
-consist of proteins (albumin),
carbohydrates (dextrans or starches),
fats (lipid emulsion), and animal
collagen (gelatin).
_______________________________
____
Types
o Albumin 5% and 25% (from human
donors)
Protein produced by liver
o Dextran 40, 70, or 75 (a glucose
solution)
o Hetastarch.
Indication
Adverse effect
-treat a wide variety of
conditions including shock and
burns, or whenever the patient
requires plasma volume
expansion.
-Colloids are less likely than
crystalloids to cause edema
because of the larger volumes of
crystalloids needed to achieve
the desired clinical effect.
-Crystalloids are better than
colloids for emergency shortterm plasma volume expansion.
__________________________
____
Albumin
-Usually safe
-Natural protein that is normally
produced by the liver
______________
__
-Range
The total protein
level must be in
the range of 7.4
g/dL. If this level
falls below 5.3
g/dL, fluid shifts
from blood
vessels into the
tissues.
-Responsible for generating
approximately 70% of the COP
-Sterile solution of serum
albumin that is prepared from
pooled blood, plasma, serum, or
placentas obtained from healthy
human donors
-Pasteurized to destroy any
contaminants
-May cause
altered
coagulation,
resulting in
bleeding
-Have no clotting
factors or
oxygen-carrying
capacity
-Rarely, dextran
therapy causes
anaphylaxis or
renal failure
Blood products
Mode of action
Only class of fluids that
are able to carry oxygen
˜-Increase tissue
oxygenation
˜-Increase PV
Indication
-Improved energy and
increasing tolerance for
activities of daily living as a
result of the treatments with
blood products.
- Pulse oximeter readings will
also show improved readings.
Adverse effect
-Incompatibility with
recipient’s immune system
-Crossmatch testing
-Transfusion reaction
-Anaphylaxis
˜-Most expensive and
least available fluid
because they require
human donors
- Treat a wide variety of clinical
conditions; the blood product
used depends on the specific
indication.
-Transmission of pathogens to
recipient (hepatitis, human
immunodeficiency virus)
-˜Increase colloid osmotic
pressure and PV
-Pull fluid from
extravascular space into
intravascular space
(plasma expanders)
-Red blood cell products
also carry oxygen
-Increase body’s supply
of various products (e.g.,
clotting factors,
hemoglobin)
Types of blood products
o Cryoprecipitate and plasma protein factors
Management of acute bleeding (greater than 50% slow blood loss or 20%
acutely)
o Fresh-frozen plasma (FFP)
Increase clotting factor levels in patients with demonstrated deficiency
o Packed red blood cells (PRBCs)
To increase oxygen-carrying capacity in patients with anemia, in patients
with substantial hemoglobin deficits, and in patients who have lost up to 25% of their total
blood volume
o Whole blood
Same as for PRBCs except that whole blood is more beneficial in cases of
extreme (greater than 25%) loss of blood volume because whole blood
also contains plasma
Contains plasma proteins, which help draw fluid back into blood vessels
from surrounding tissues
Electrolytes:
˜Principal ECF electrolytes
-Sodium cations (Na )
+
-Chloride anions (Cl )
−
˜Principal ICF electrolyte
-Potassium (K )
+
˜Others
-Calcium, magnesium, phosphorus
Electrolytes
Control of
electrolytes
Adverse effects
o Reninangiotensinaldosterone system
o Antidiuretic
hormone system
o Sympathetic
nervous system
When these neuroendocrine systems are
out of balance, adverse electrolyte
imbalances commonly result.
Risk
-Patients who receive
diuretics are at risk of
electrolyte abnormalities.
o Positively charged cations
Sodium (ECF), potassium (ICF), calcium, magnesium
o Negatively charged ions
Chloride (ECF), phosphate, bicarbonate
Potassium
-Most abundant positively charged electrolyte inside cells
-95% of body’s potassium is intracellular
-Potassium content outside of cells ranges from 3.5 to 5 mEq/L
-Potassium levels are critical to normal body function
˜Potassium obtained from foods
-Fruit and fruit juices (bananas, oranges, apricots, dates, raisins, broccoli, green beans,
potatoes, tomatoes), meats, fish, wheat bread, and legumes
˜Excess dietary potassium excreted via kidneys
-Impaired kidney function leads to higher serum levels, possibly toxicity
Potassium
Mode of action
-Muscle contraction
-Transmission of
nerve impulses
-Regulation of
heartbeat
-Maintenance of
acid–base balance
-Isotonicity
Indication
- indicated in the treatment or
prevention of potassium depletion.
-Treatment or prevention of
potassium depletion when dietary
means are inadequate
˜Other therapeutic uses
-Stop irregular heartbeats
-Management of tachydysrhythmias
that can occur after cardiac surgery
Adverse effect
-Oral preparations

Diarrhea, nausea,
vomiting, GI bleeding,
ulceration
-IV administration


Pain at injection site
Phlebitis
-Excessive administration


Hyperkalemia
Toxic effects
Contraindication to potassium replacement products include known allergy to a specific drug
product, hyperkalemia from any cause, severe renal disease, acute dehydration, untreated
Addison disease, severe hemolytic disease, and conditions involv-ing extensive tissue
breakdown (e.g., multiple trauma, severe burns).
Hypokalemia
-a serum potassium level of less than 3.5
mEq/L.
Hyperkalemia
-potassium level exceeding 5.5 mEq/L.
-Symptoms include muscle weakness,
-Early symptoms of hypokalemia include: paresthesia, paralysis, cardiac rhythm
irregularities that can result in ventricular

hypotension, lethargy, mental
fibrillation, and cardiac arrest.
confusion, nausea, and muscle
weakness.
________________________________________
____

Late symptoms include cardiac
dysrhythmias (the patient may feel
palpitations or shortness of
breath), neuropathies, and
paralytic ileus.
 Hypokalemia can cause digoxin
toxicity → ventricular
dysrhythmias
_________________________________
______
Excessive K loss
-Alkalosis
-Corticosteroids
-Diarrhea
-Ketoacidosis
-Laxative misuse
-Hyperaldosteronism
-Increased secretion of mineralocorticoids
Excessive volume of K
-Burns
Treatment of severe hyperkalemia
-Thiazide, thiazide-like, and loop
diuretics
-IV sodium bicarbonate, calcium gluconate or
calcium chloride, dextrose with insulin
-Vomiting
-Sodium polystyrene sulfonate (Kayexalate) or
hemodialysis to remove excess potassium
-Malabsorption
-Burns
-Trauma
-Metabolic acidosis
-Infections
-Potassium supplements
-ACE inhibitors
-Renal failure
-Excessive loss from cells
-Potassium-sparing diuretics
________________________________________
_______
“Antidote” for hyperkalemia:
-Others
Sodium (135-145 mEq/L)
Mode of
action
-Control of
water
distribution
-Fluid and
electrolyte
balance
Indications
Adverse Effect
˜Main indication
Oral
administration
-Treatment or prevention of sodium depletion when
dietary measures are inadequate
•Nausea,
vomiting,
cramps
-Mild
•Treated with oral sodium chloride and/or fluid restriction
-Severe
IV
administration
-Osmotic
pressure of
body fluids
-Participation
in acid–base
balance
•Treated with IV NS or lactated Ringer’s solution
- A new class of drugs for the treatment of euvolemic
(normal fluid volume) hyponatremia is the dual
arginine vasopressin (AVP) V1A and V2 receptor
antagonists. These drugs are conivaptan (Vaprisol) and
tolvaptan (Samsca). This class of drugs is often referred
to as vaptans. Specific information on conivaptan is listed
under its drug profile
Hyponatremia
•Venous
phlebitis
Hypernatremia
Symptoms
Symptoms
•Lethargy, stomach cramps, hypotension,
vomiting, diarrhea, seizures
•Water retention (edema), hypertension
Causes
•Same causes as hypokalemia; also excessive
perspiration (during hot weather or physical
work), prolonged diarrhea or vomiting, or renal
disorders
Manifestation
-Lethargy
-Stomach cramps
-Hypotension
-Vomiting
-Diarrhea
-Seizures
•Red, flushed skin; dry, sticky mucous
membranes; increased thirst; elevated
temperature; decreased urine output
Causes
•Poor renal excretion stemming from
kidney malfunction; inadequate water
consumption and dehydration
Manifestation
-Edema
-Hypertension
-Red, flushed skin
-Dry, sticky mucous membranes
-Increased thirst
-Elevated temperature
-Decreased urine output
Nursing care plan
-Assess baseline fluid volume and electrolyte status.
-Assess baseline vital signs.
-Assess skin, mucous membranes, daily weights, and input and output.
-Before giving potassium, assess electrocardiogram.
-Assess for contraindications to therapy.
-Assess transfusion history.
-Establish venous access as needed
-Monitor serum electrolyte levels during therapy.
-Monitor infusion rate, appearance of fluid or solution, and infusion site.
-Observe for infiltration and other complications of IV therapy.
-Parenteral infusions of potassium must be monitored closely.
-IV potassium must not be given at a rate faster than 10 mEq/hrto patients who are not on
cardiac monitors. For critically ill patients on cardiac monitors, rates of 20 mEq/hr or more
may be used.
-NEVER give as an IV bolus or undiluted
˜Oral forms of potassium
-Must be diluted in water or fruit juice to minimize GI distress or irritation
-Monitor for complaints of nausea, vomiting, GI pain, and GI bleeding
Chapter 37: Respiratory Drugs (8 Questions)
1. Bronchial Asthma
 Recurrent and reversible SOB
 Occurs when the airways of the lungs become narrow as a result of:
o Bronchospasms
o Inflammation of the bronchial mucosa
o Edema of the bronchial mucosa
o Production of viscous mucus
 Symptoms
o Wheezing
o Difficulting breathing
 Status asthmaticus
o Prolonged asthma attack that doesn’t respond to typical drug therapy
o May last several minutes to hours
o Medical emergency
2.
Asthma
 Four Categories
o Intrinsic (occurring in patients with no history of allergies)
o Extrinsic (occurring in patients exposed to a known allergen)
o Exercise induced
o Drug induced
3.
Chronic Obstructive Pulmonary Disease (COPD)
 Chronic Bronchitis
o Continuous inflammation and low-grade infection of the bronchi
o Excessive secretion of mucus and certain pathologic changes in the
bronchial structure
o Often occurs as a result of prolonged exposure to bronchial irritants

Emphysema
o Air spaces enlarge as a result of the destruction of alveolar walls
o The surface area where gas exchange takes place is reduced
o Effective respiration is impaired
Bronchodilator
Nonbronchodilators
Beta-adrenergic agonist (SABA or LABA) Leukotriene receptor antagonist (LTRAs)

Nonselective adrenergic

Nonselective beta-adrenergic

Inhaled

Selective beta 2 drugs

Systemic

IV
Anticholinergics
Xanthine derivatives
Corticosteroids
Mast cell stabilizer
Phosphodiesterase-4 inhibitor
Monoclonal Antibody Antiasthmatic
1. Discuss the mechanism of action, indications, contraindications, cautions, drug
interactions, dosages, routes of administrations, adverse effects, and toxic effects of
the bronchodilators and other drugs.
BRONCHODILATOR
Beta-Adrenergic Agonist
Mechanism of Action
- Reduces airway constriction and restore
normal airflow
+Activation of beta2 receptors relaxes
smooth muscle in the airway and results in
bronchial dilation and increased airflow
+ Stimulate adrenergic receptors in
sympathetic nervous system:
Sympathomimetics
Contraindications
-Known drug allergy
-Uncontrolled hypertension
-Cardiac dysrhythmias
- High risk of stroke (because of the
vasoconstrictive drug action)
Indications
Adverse
Effect
-Relief of bronchospasm related to
asthma, bronchitis, and other
pulmonary diseases
-Treatment and prevention of acute
attacks
- Hypotension and shock
See below
Interactions
Toxicity
-Nonselective beta blockers
-MAOIs
-Sympathomimetics
-Monitor patients with diabetes:
increased blood glucose levels
(hyperglycemia)
None
Nonselective
adrenergics
-Stimulate alpha, beta1 (cardiac), and beta2 () receptors
-Example: epinephrine (EpiPen)
-A/E: insomnia, restlessness, anorexia, vascular headache,
hyperglycemia, tremor, cardiac stimulation
Nonselective betaadrenergics
-Stimulate both beta1 and beta2 receptors
-Example: metaproterenol
-A/E: cardiac stimulation, tremor, angina pain, vascular headache,
hypotension
Selective beta 2 drugs
-Stimulate only beta2 receptors
-Example: albuterol
-A/E: hypo/hypertension, vascular headache, tremor
Short-acting beta
agonist (SABA)
-Albuterol (Ventolin, ProAir)
 Most commonly used SABA
 Beta2-specific
 Limit use – loses its beta2-specific actions at larger doses
→ beta1 receptors stimulated: nausea, increased anxiety,
palpitations, tremors, tachycardia → Levalbuterol
 Oral and inhalation
-Levalbuterol (Xopenex)
-Pirbuterol (Maxair)
-Terbutaline (Brethine)
-Metaproterenol (Alupent)
Long-acting beta
agonist (LABA)
- Older LABA
 Arformoterol (Brovana)
 Formoterol (Foradil, Perforomist)
 Salmeterol (Serevent)
o Beta2
o Maintenance of asthma and COPD (with inhaled
corticosteroid) → Not for acute treatment (longer onset of
action)
o Never more than twice daily
-Newest LABA
 Indacaterol (Arcapta Neohaler)
 Vilanterol + fluticasone (Breo Ellipta)
 Vilanterol + umeclidinium (anticholinergic) (Anoro Ellipta)
o Ellipta refers to a new delivery system
Nursing Management








Albuterol, if used too frequently, loses the beta2-specific
actions at larger doses
This results in beta1 stimulation, causing nausea, increased
anxiety, palpitations, tremors, and increased HR
Teach patients to take bronchodilators exactly as prescribed
Ensure that the patients known how to use inhalers and MDIs
and have patient demonstrate its use
Spacers can be used to increase amount of medication
delivered
Monitor for adverse effects
Ensure that patients take medications exactly, no
omissions/double doses
Inform patients to report insomnia, jitteriness, restlessness,
palpitations, chest pain, etc
Anticholinergics
Mechanism of Action
Indications
Adverse Effect
Binds to ACh receptors
 Acetylcholine →
bronchial constriction
and narrowing of
airways
 Indirectly cause
airway relaxation and
dilation
-Prevention of the bronchospasm
associated with chronic bronchitis or
emphysema; not for the management
of acute symptoms → Help to reduce
secretions in COPD patients
-Dry mouth or throat
-Nasal congestion
- Heart palpitations Gastrointestinal (GI)
distress -Headache
-Coughing
-Anxiety
Contraindications
Interactions
Toxicity and
Managing Overdose
-KDA, including allergy to
atropine
-Cautions is necessary with
acute narrow-angle glaucoma
and prostate enlargement
-Anticholinergics
Possible addictive
toxicity may occur
Ipratropium (Atrovent)
Description





Nursing
Management

Oldest and most common
Treat the symptoms of COPD
Available both as a liquid aerosol for inhalation and as a
multidose inhaler
Usually dosed twice daily
Others:
○ Tiotropium (Spiriva)
○ Aclidinium (Tudorza)
○ Umeclidinium (Incruse Ellipta)
Persons using anticholinergic
○ Remember to assess for h/o heart palpitations, GI distress,
BPH, urinary retention, and glaucoma
Xanthine Derivatives
Mechanism of Action
-Plant alkaloids: caffeine,
theobromine, and theophylline
-Only theophylline is used as a
bronchodilator
-Cause bronchodilation by relaxing
smooth muscle in the airways
-Result: relief of bronchospasm and
greater airflow into/out of the lungs
-Synthetic xanthines: aminophylline
and dyphylline
-Result: decreased cAMP levels,
smooth muscle relaxation,
bronchodilation, and increased
airflow
-Also cased central nervous system
(CNS) stimulation
-Also cause cardiovascular
stimulation: increased force of
contraction and increased heart rate,
resulting in increased cardiac output
and increased blood flow to the
kidneys (diuretic effect)
Contraindications
-KDA
-Uncontrolled cardiac dysrhythmias
-Seizure disorders
-Hyperthyroidism
-Peptic ulcers
Indications
-Dilation of airways in
asthma, chronic bronchitis,
and emphysema
-Mild to moderate cases of
acute asthma
-NOT for management of
acute asthma attack
-Adjunct drug in the
management of COPD
-Not used as frequently
because of potential for drug
interactions and variables
related to drug levels in the
blood
-Cardiac stimulants in
infants
Interactions
-Cimetidine, oral
contraceptives, allopurinol,
certain antibiotics, influenza
vaccine, and others
 Cigarettes enhance
xanthine metabolism
 Charcoal-broiled,
high-protein, lowcarb food reduce
xanthines
Adverse Effect
-Nausea, vomiting,
anorexia Gastroesophageal
reflux during sleep
-Sinus tachycardia,
extrasystole,
palpitations,
ventricular
dysrhythmias
-Transient increased
urination
-Hyperglycemia
-Treated by repeated
doses of activated
charcoal
Toxicity and
Managing Overdose
None
Theophylline
Description


Most commonly used xanthine derivative
Oral, rectal, injectable (as aminophylline), and topical dosage forms




Nursing
Management







Aminophylline: intravenous (IV) treatment of patients with status
asthmaticus who have not responded to fast-acting agonists such as
epinephrine
Only theophylline is used as a bronchodilator
 Slow onset - do not use for acute asthma attack
Therapeutic range for theophylline blood level is 10-20 mcg/mL
Most clinicians now advised levels between 5 and 15 mcg/ml
Contraindications: history of PUD or GI disorders
Cautious use: cardiac disease
Timed-release preparations should not be crushed/chewed (cause
gastric irritation)
Report to prescriber: Vomiting, nausea, restlessness, insomnia,
irritability, tremors
Be aware of drug interactions with cimetidine, oral contraceptives,
allopurinol, certain antibiotics, influenza vaccine, and others
Cigarette smoking enhances xanthine metabolism
Interacting foods include charcoal-broiled, high-protein, and
low-carbohydrate foods → These foods may reduce serum levels
of xanthines through various metabolic mechanisms
NONBRONCHODILATORS
Leukotriene receptor antagonist (LTRAs)
Mechanism of Action
-Alleviates asthma symptoms by
reducing inflammation
-Inflammation in lungs is blocked,
and asthma symptoms are relieved
Drug Effects:
-Prevent smooth muscle contraction
of the bronchial airways
- Decrease mucus secretion
- Prevent vascular permeability
- Decrease neutrophil and leukocyte
infiltration to the lungs preventing
inflammation
Contraindications
Indications
-Prophylaxis and long-term
treatment and prevention of
asthma in adults and children
12 years of age and older
-NOT meant for
management of acute
asthmatic attacks Improvement seen in about 1
week
Interactions
Adverse Effect
-Headache
-Nausea
-Dizziness
-Insomnia
The most common A/E
of montelukast and
zafirlukast include
headache, nausea, and
diarrhea
Toxicity and
Managing Overdose
-Known drug allergy
-Previous adverse drug reaction
-Allergy to povidone, lactose,
titanium dioxide, or cellulose
derivatives is also important to note
because these are inactive ingredients
in these drugs
-Montelukast has few drug
interactions than zafirlukast
or zileuton
-Phenobarbital and rifampin,
both of which are enzyme
inducers, decrease
montelukast concentrations.
Montelukast
Description




Nursing
Management






Blocks leukotriene d4 receptors to augment the inflammatory
response
Approved in children 1 year and older
Contraindicated in patients with known sensitivity
Pregnancy category B
Ensure that the drug is being used for chronic management of
asthma, not acute asthma
Teach the patient the purpose of the therapy
Improvements should be seen in about 1 week
Advise patients to check with prescriber before taking OTC or
prescribed medications to determine drug interactions
Assess liver function before beginning therapy/throughout
therapy
Teach patients to take medications every night on a continuous
schedule even if symptoms improve
Corticosteroids (Glucocorticoids)
Mechanism of Action
Indication
-Stabilize membranes of cells that
release harmful
bronchoconstriction substances
→ These cells are called
leukocytes, or white blood cells
-Increase responsiveness of
bronchial smooth muscle to betaadrenergic stimulation
-Dual effect of both reducing
inflammation and enhancing the
activity of beta agonists
-Persistent asthma
-Used with the betaadrenergic agonists
-Systemic corticosteroids
are generally used only to
treat acute exacerbations
or severe asthma
Adverse Effect
-Pharyngeal irritation
-Coughing
-Dry mouth
-Oral fungal infections
-System effects are rare
Contraindications
Interactions
-Drug allergy
-Hypersensitivity to
glucocorticoids
-Patients whose sputum tests
positive for Candida organisms
-Patients with system fungal
infection
-More likely in systemic
than inhaled
-May increase serum
glucose levels,
Cyclosporine and
tacrolimus
-Itraconazole- reduces
clearance -Phenytoin,
phenobarbital, and
rifampin- enhances
clearance
Nursing Management
-Teach patients to gargle and
rinse mouth with lukewarm
water afterwards (prevent
fungal infections)
-If beta agonist
bronchodilator and
corticosteroid inhaler are
both ordered, bronchodilator
used first
-Teach patients to monitor
disease with a peak flow
meter
-Encourage use of a spacer
device to ensure successful
inhalations
-Teach patient how to keep
inhalers/nebulizers clean
Phosphodiesterase-4 Inhibitor
Roflumilast
(Daliresp)


Indicated to prevent coughing and excess mucus from worsening
and to decrease the frequency of life-threatening COPD
exacerbations
Adverse effects include nausea, diarrhea, headache, insomnia,
dizziness, weight loss, and psychiatric symptoms
Monoclonal Antibody Antiasthmatic
Omalizumab (Xolair), mepolizumab
(Nucala), reslizumab (Cinqair)
-Selectively binds to the immunoglobulin E, limits
the release of mediators of the allergic response
-Given by injection
-Potential for producing anaphylaxis
-Monitor closely for hypersensitivity reactions
Indication: Moderate to severe asthma
2.
Develop a nursing care plan that includes all phases of the nursing process for
patients who use bronchodilators and other drugs
Nursing Assessment

Encourage patients to take measures that promote a generally good state of health so as
to prevent, relieve, or decrease symptoms of COPD
○ Avoid exposure to conditions that precipitate bronchospasm (allergens,
smoking, stress, air pollutants)
○ Adequate fluid intake
○ Compliance with medical treatment
○ Avoid excessive fatigue, heat, extremes in temperature, and caffeine


Encourage patients to get prompt treatment for flu or other illnesses and to get vaccinated
against pneumonia or flu
Encourage patients to always check with their physicians before taking any other
medications, including OTC
Nursing Implications

Perform a thorough assessment before beginning therapy, including:
○ Skin color
○ Baseline vital signs
○ Respirations (should be between 12 and 24 breaths/min)
○ assessment, including pulse oximetry
○ Sputum production
○ Allergies
○ History of problems
○ Other medications ○ Smoking history

Monitor for therapeutic effects:
○ Decreased dyspnea
○ Decreased wheezing, restlessness, and anxiety
○ Improved patterns with return to normal rate and quality
○ Improved activity tolerance
○ Decreased symptoms and increased ease of breathing
Inhalers: Patient Education


For any inhaler prescribed, ensure that the patient is able to self-administer the
medication
○ Provide demonstration, watch patient demonstrate
○ Ensure patient knowns correct time intervals
○ Provide a spacer for patients with difficulty coordinating breathing with inhaler
○ Ensure patient knows how to keep track of number of doses in inhaler device
Chapter 50: Acid-Controlling Drugs
* KEY TERMS:








Antacids: Basic compounds composed of different combinations of acid-neutralizing
ionic salts.
Chief cells: Cells in the stomach that secrete the gastric enzyme pepsinogen (a precursor
to pepsin).
Gastric glands: Secretory glands in the stomach containing the following cell types:
parietal, chief, mucous, endocrine, and enterochromaffin.
Gastric hyperacidity: The overproduction of stomach acid.
Hydrochloric acid (HCl): An acid secreted by the parietal cells in the lining of the
stomach that maintains the environment of the stomach at a pH of 1 to 4. If untreated, it
can lead to reflux, ulcer disease, esophageal damage, and even esophageal cancer.
Mucous cells: Cells whose function in the stomach is to secrete mucus that serves as a
protective mucous coat against the digestive properties of HCl. Also called surface
epithelial cells.
Parietal cells: Cells in the stomach that produce and secrete HCl. These cells are the
primary site of action for many of the drugs used to treat acid-related disorders.
Pepsin: An enzyme in the stomach that breaks down proteins.
1. Discuss the physiologic influence of various pathologies, such as peptic ulcer disease,
gastritis, spastic colon, gastroesophageal reflux disease, and hyperacidic states, on the
health of patients and their gastrointestinal tracts.
Cells of Gastric Gland
The 3 primary types of glands in stomach:
1. Cardiac gland: are located around the cardiac sphincter (also known as the
gastroesophageal sphincter)
2. Pyloric glands: are in the pyloric region and in the transitional area between the pyloric
and fundic zones.
3. The gastric glands: are in the fundus, also known as the greater part of the body of the
stomach
a.
Parietal cells:
 Produce and secrete Hydrochloric Acid (HCl)
o Secrete HCl when stimulated by food, caffeine, chocolate, alcohol, large
fatty meals and emotional stress
o Maintain stomach at pH 1-4Acidity aids in digestion of food and defenses
against microbial infection in GI tract
 Primary site of action of many drugs used to treat acid-related disorders
b. Chief cells: Secrete pepsinogen (a proenzyme) → pepsin when exposed to acid →
pepsin breaks down proteins (proteolytic)
c.
Mucous cells: Mucus provides a protective coat against self-digestion by
HCl and digestive enzyme
2. Describe the mechanisms of action, indications, cautions, contraindications, drug
interactions, adverse effects dosages, and routes of administration for the following classes
of acid-controlling drugs: antacids, histamine 2 (H2)-blocking drugs (H2 receptor
antagonists), proton pump inhibitors, and acid suppressants.
Diseases

Peptic Ulcer Disease (PUD): Gastric or duodenal ulcers involving digestion of GI
mucosa by enzyme pepsin
Helicobacter pylori (H. pylori)
 Bacterium found in 90% if duodenal ulcers and 70% gastric ulcers
 Tx: - 10-14 days PPI + clarithromycin + amoxicillin or metronidazole
 10-14 days PPI + bismuth subsalicylate + tetracycline + metronidazole

-
Stress - Ulcer




Stress-related mucosal damage: ↓ blood flow, mucosal ischemia, hypoperfusions,
and reperfusion injury
GI lesions common in ICU within first 24 hours after admission
NG tubes and Ventilators predispose patient to GI bleeding
Prophylactic Tx: histamine receptor-blocking or PPI
Antacids
Mechanism of Action
Neutralize acid secretions,
promote gastric mucosal
defense mechanisms,
stimulate section of:
Interaction
- Time antacid administration
with medication regimen (long
before or after)

- Mucus – protective barrier
against HCl
- Bicarbonate – helps buffer
acidic properties of HCl




Reduction of pain by
raising gastric pH 1
pt (1.3 to 2.3)
Moderate inhibition
of pepsin
↑ resistance of
stomach lining
irritation
↑ tone of cardiac
sphincter


Chelation – chemical
binding or inactivation or
insoluble complexes →
reduced absorption of
other drugs
Increased stomach pH
o ↑ absorption of
basic drugs
o ↓ absorption of
acidic drugs
Increased urinary pH
o ↑ excretion of
acidic drugs
o ↓ excretion of
basic drugs
Drugs
Aluminum salts
- AE: constipating effects
(often used with Mg)
- Recommended for renal
disease (more easily
excreted)
 Aluminum
carbonate: Basaljel
 Hydroxide salt:
AlternaGEL
 Combination
products
(aluminum and
magnesium):
Gaviscon, Maalox,
Mylanta, Di-Gel
Magnesium salts
- AE: diarrhea (used with
other drugs to counteract
this effect)
- CI: renal failure
- Prostaglandins – prevent
activ--ation of proton pump

Hydroxide salt:
magnesium
hydroxide (Milk of
Magnesia)
 Carbonate salt:
Gaviscon (also a
combination
product)
 Combination
products such as
Maalox, Mylanta
(aluminum and
magnesium)
Calcium salts
- Carbonate is most
common
- AE: constipation, kidney
stones, rebound
hyperacidity
- CI: renal disease,
prolonged use may cause
increased gastric acid
secretion
(hyperacidity rebound)
- Often advertised as
“extra” source of calcium:
Tums (calcium carbonate)
Sodium bicarbonate
- Highly soluble
- Buffers acidic properties
of HCl
- Quick onset, shortduration
- AE: metabolic alkalosis
- CI: sodium content →
HF, HTN, or renal
insufficiency
- Neutralize stomach acid
- Salts of aluminum,
magnesium, calcium,
and/or sodium





Aluminum and
calcium acidneutralizing + cause
constipation
Magnesium acidneutralizing +
promotes GI motility
o Must be
avoided in
renal failure
Calcium → kidney
stones and ↑ gastric
acid secretion
Sodium bicarbonate
is highly soluble but
short-duration
May also contain
simethicone antiflatulent (antigas)
Contraindications
- allergy
- severe renal failure
- electrolyte imbalances
- GI obstruction
Indication
- peptic ulcer
- gastritis
- gastric hyperacidity
- heartburn
Toxicity and Managing
Overdose
Histamine 2 (H2) Receptor Antagonists
Mechanism of Action
_ Competitively block the
H2 receptor of acidproducing parietal cells
_ Reduced hydrogen ion
secretion from the parietal
cells
_ Increase in the pH of the
stomach
_ Relief of many of the
symptoms associated with
hyperacidity-related
conditions
Contraindications
_ KDA
_ Liver and/or kidney
dysfunction: Just need
dosage adjustment (not
contraindicated)
Indications
_ Gastroesophageal reflux
disease (GERD)
_ PUD
_ Erosive esophagitis
_ Adjunct therapy to control
upper GI bleeding
_ Zollinger-Ellison syndrome
Interactions
Cimetidine (Tagamet)
_ Binds with P-450 microsomal
oxidase system in the liver,
resulting in inhibited oxidation
of many drugs
and increased drug levels
_ All H2 antagonists may
inhibit the absorption of drugs
that require an acidic GI
environment for absorption.
_ Because of its potential to
cause drug interactions,
cimetidine has been largely
replaced by ranitidine and
famotidine.
_ Cimetidine is still used to treat
certain allergic reactions.
_ Smoking has been shown to
decrease the effectiveness of H2
blockers.
_ For optimal results, H2
receptor antagonists are taken 1
to 2 hours before antacids.
Adverse Effect
_ Overall, very few adverse
effects
_ CNS: confusion and
disorientation (elderly)
_ Cimetidine may induce
impotence and
gynecomastia.
_ Thrombocytopenia has
been reported with
ranitidine and famotidine.
Toxicity and Managing
Overdose
Proton Pump Inhibitors (PPIs)
Mechanism of Action
parietal cells release protons
(H+ ions) during HCl
production = proton pump
o Bind to H+/K+ ATPase
enzyme → prevents movement
of H+ ions from parietal cells
into stomach → achlorhydria –
all gastric acid secretion is
temporarily blocked
Indications
Adverse Effect
GERD, erosive esophagitis,
duodenal and benign gastric ulcers
(short-term), ZollingerEllison
syndrome, NSAID-induced ulcers,
stress ulcer prophylaxis, H.pyloriinduced ulcers
possible GI infections
(C. diff), osteoporosis
with LT use,
pneumonia, Mg
depletion, ??link
with dementia and
SLE??
Interactions
Toxicity and
Managing Overdose
Drugs
- Lansoprazole (Prevacid)
- Omeprazole (Prilosec)
- Rabeprazole (AcipHex)
- Pantoprazole (Protonix)
- Esomeprazole (Nexium)
diazepam, phenytoin, warfarin,
ketoconazole, ampicillin, iron salts,
digoxin, clopidogrel,
sucralfate (delays absorption of
PPIs), food decreases absorption of
PPIs
liver disease
Miscellaneous Acid-Controlling Drugs
Sucralfate (Carafate)




Binds to base of ulcers and erosions, forming a protective barrier against pepsin
(cytoprotective drug) also binds and concentrates epidermal growth factor which
promotes ulcer healing → “liquid bandage”
Indication: stress ulcers, PUD
 Binds with phosphate → used in chronic renal failure to ↓ phosphate levels
AE: constipation, nausea, and dry mouth
DI: impairs absorption of other drugs, give other drugs 2 hours before
Misoprostol (Cytotec)

Prostaglandin E analogue
 Prostaglandins have cytoprotective activity
o Protect gastric mucosa from injury by enhancing local production of
mucus and bicarbonate
o Promote local cell regeneration
o Maintain mucosal blood flow


Indication: prevention of NSAID-induced gastric ulcers, duodenal ulcers
AE: can produce abdominal cramps and diarrhea
Simethicone (Mylicon)

Antiflatulent drug: Breaks down mucus-coated gas bubbles into smaller bubbles →
decreased gas pain and increased expulsion via mouth or rectum
3. Develop a nursing care plan that includes all phases of the nursing process for patients
receiving acid-controlling drugs.
_ Assess for allergies and preexisting conditions that may restrict the use of antacids, such as:





Fluid imbalances
Renal disease
GI obstruction
HF
Pregnancy
_ Patients with HF or hypertension should not use antacids with high sodium content.
Chapter 51: Bowel Disorder Drugs
Diarrhea



Acute diarrhea
 Sudden onset in a previously healthy person
 Lasts from 3 days to 2 weeks
 Self-limiting
 Resolves without sequelae
 Causes: bacteria, viruses, drug induced, nutritional factors, protozoa
Chronic diarrhea
 Lasts for more than 3 to 4 weeks
 Associated with recurring passage of diarrheal stools, fever, loss of appetite, nausea,
vomiting, weight loss, and chronic weakness
 Causes: tumors, DM, Addison’s disease, hyperthyroidism, IBS, AIDS
Treatment
 Stop stool frequency
 Decrease ab cramps
 Replenish fluids/electrolytes
 Prevent weight loss and nutritional deficits
Adsorbents
Mechanism of Action
Indications
-Coat walls of GI tract
Mild diarrhea
-Bind to causative agent
and eliminate it thru
stool
Contraindications
Adverse Effect
-Increased bleeding time
-Constipation
-Dark stools
-Confusion
-Tinnitus
-Metallic taste
-Blue tongue
Interactions
Examples
-Decrease absorption of
many drugs (digoxin,
quinidine, hypoglycemia
drugs)
- Increase warfarin
effects (bind to vit K)
-Increase toxic effects of
methotrexate
-Bismuth subsalicylate (Pepto-Bismol)
→ caution in children and teenagers who
have or are recovering from chickenpox
or influenza b/c the risk of Reye’s
syndrome.
-Activated charcoal
-Antilipemic drugs: colestipol and
cholestyramine
Anticholinergics
Mechanism of Action
-Decrease muscle tone and
peristalsis
-Slows movement of feces
thru GI
-Drying effect, reduce
gastric secretions
Indications
-More severe diarrhea
Contraindications
Interactions
-Narrow-angle glaucoma,
GI obstruction, myasthenia
gravis, paralytic ileus, toxic
megacolon
-Decrease by
coadministration w/ antacids
- Increase anticholinergic
effects when give w/
Amantadine, TCAs, MAOIs,
opiates, and antihistamines
Belladonna alkaloid
combinations




Adverse Effect
-Urinary retention, impotence,
headache, dizziness, confusion,
anxiety, drowsiness, dry skin,
flushing, blurred vision,
abdominal pain, hypotension,
tachycardia
Example
Belladonna Alkaloids
Donnatal is the most commonly used drug in this class
Donnatal tablets contain a combination of 4 different
alkaloids: atropine, hyoscyamine, phenobarbital, and
scopolamine.
Available: elixir, tablets, and extended-release tablets.
Pregnancy category C to X drugs
Opiates
Mechanism of Action
-Decrease bowel motility and pain
by relief of rectal spasms
-Decrease transit time through
bowel, ↑ absorption of
water/electrolytes
Contraindications
-Known drug allergy
Indications
More severe diarrhea
Adverse Effect
-Drowsiness, dizziness,
lethargy, n/v,
constipation, respiratory
depression, hypotension,
urinary retention, flushing
Interactions
-Addictive CNS depressant
effects if they are given w/
There are 5 opiate-related
antidiarrheal drugs:
-Any major acute GI condition,
such as intestinal obstruction or
colitis, unless the drug is ordered
by the patient’s prescriber after
careful consideration of the
specific

Diphenoxylate
with atropine



Loperamide



CNS depressants, alcohol,
opioids, sedative-hypnotics,
antipsychotics, or skeletal
muscle relaxants.
codeine, diphenoxylate
with atropine, loperamide,
paregoric, and tincture of
opium.
Diphenoxylate (Lomotil, Lonox) is a synthetic opiate agonist
structurally related to meperidine. It acts on smooth muscle of the
intestinal tract, inhibiting GI motility and excessive GI propulsion
When taken in large doses, however, the combination results in
extreme anticho-linergic effects (e.g., dry mouth, abdominal pain,
tachycardia, blurred vision)
Use of the combination of diphenoxylate and atropine is
contraindicated in patients experiencing diarrhea associated with
pseudomembranous colitis or toxigenic bacteria
Loperamide (Imodium A-D) is a synthetic antidiarrheal similar to
diphenoxylate.
It inhibits both peristalsis in the intestinal wall and also intestinal
secretion, thereby decreasing the number of stools and their water
content.
It is the only opiate antidiarrheal drug available as an OTC
medication
Loperamide is contraindicated in patients with severe ulcerative
colitis, pseudomembranous colitis, or acute diarrhea associated
with Escherichia coli
Probiotics
Mechanism of Action
Indications
-Supply missing bacteria to GI
tract
-Suppress growth of diarrheacausing bacteria
-Example: Lactobacillus
acidophilus (Bacid)
-Also known as intestinal flora modifiers and
bacterial replacement drugs
-Antibiotic-induced diarrhea
Lactobacillus

Adverse
Effect
None
Lactobacillus acidophilus (Bacid) and Lactobacillus GG (Cul-turelle)
are acid-producing bacteria prepared in a concen-trated, dried culture
for oral administration.


L. acidophilus has been used for more than 75 years for the treatment
of uncomplicated diarrhea, particularly that caused by antibiotic
therapy, which destroys normal intestinal flora
Commonly used probiotic is Saccharo-myces boulardii (Florastor),
which is used to treat Clostridium difficile infections
Nursing Implication








Obtain thorough history of bowel patterns, general state of health, and recent history of
illness or dietary changes; assess for allergies.
Do not give bismuth subsalicylate to children or teenagers with chickenpox or
influenza because of the risk of Reye’s syndrome.
Use adsorbents carefully in older patients and those with decreased bleeding time,
clotting disorders, recent bowel surgery, or confusion.
Do not administer anticholinergics to patients with a history of narrow-angle glaucoma,
GI obstruction, myasthenia gravis, paralytic ileus, or toxic megacolon
Teach patients to take medications exactly as prescribed and to be aware of their fluid
intake and dietary changes.
Assess fluid volume status, input and output, and mucous membranes before, during,
and after initiation of treatment
Teach patients to notify their prescribers immediately if symptoms persist.
Monitor for therapeutic effect.
Constipation


Symptom, not disease, caused by variety of disease or drugs
Treatment:
 Surgical
 Nonsurgical treatments
 Dietary (e.g., fiber supplementation)

Behavioral (e.g., increased physical activity)

Pharmacologic
Irritable Bowel Syndrome (IBS)





Cramps, diarrhea, constipation
Avoid irritating foods and taking OTC laxatives or antidiarrheal drugs
Liver function and cardiac function before drug therapy
Drugs:
 Tegaserod (Zelnorm)
 Lubiprostone (Amitiza)
 Alosetron (Lotronex)
Nursing Implications:
 Perform a general assessment and additional assessment of liver functioning as
well as assessment for any underlying cardiac disease.
 Follow administration guidelines.

a.
Assess for therapeutic response.
Laxative
 Long-term use of laxatives often results in decreased bowel tone and dependency
 Laxatives not administered with undiagnosed abdominal pain
Bulk Forming
Mechanism of Action
-High fiber
-Absorb water to increase bulk
-Distended bowel to initiate reflex bowel
activity
Contraindications
-Drug allergy
-Cautious use in the presence of the
following: Acute surgical abdomen,
appendicitis symptoms such as abdominal
pain, nausea, and vomiting , fecal impaction
(mineral oil enemas excepted); intestinal
obstruction; and undiagnosed abdominal
pain
Methylcellulose



Psyllium



Indications
Adverse Effect
Acute/Chronic
constipation, IBS,
diverticulosis → Safe
to use long term
-Impaction, fluid
overload, electrolyte
imbalances,
esophageal blockage,
gas formation, allergic
reaction
→ Drink w/at least 8
oz water to avoid
esophageal blockage
Interactions
Toxicity and
Managing Overdose
Decrease the
absorption of
antibiotics, digoxin,
salicylates,
tetracyclines, and
warfarin
Methylcellulose (Citrucel) is a synthetic bulk-forming laxative that
attracts water into the intestine and absorbs excess water into the
stool, stimulating the intestines and increasing peristalsis
Specific contraindications include GI obstruction and hepatitis.
Methylcellulose is an oral drug available in powdered form that
provides approximately 2 g of fiber per heaping tablespoon.
Psyllium (Metamucil) is a natural bulk-forming laxative obtained
from the dried seed of the Plantago psyllium plant
Contraindicated in patients with intestinal obstruction or fecal
impaction.
Its use is also contraindicated in patients experiencing abdominal
pain and/or nausea and vomiting
Emollient (Stool softener, Lubricant laxatives)
Mechanism of Action
-Promote move water and fat in stools
-Lubricate fecal material and intestinal walls
Contraindications
-Drug allergy
-Cautious use in the presence of the following:
Acute surgical abdomen, appendicitis
symptoms such as abdominal pain, nausea, and
vomiting , fecal impaction (mineral oil enemas
excepted); intestinal obstruction; and
undiagnosed abdominal pain
Docusate
salts



Mineral
oil





Indications
Adverse Effect
Acute/Chronic
constipation, fecal
impaction, anorectal
conditions
Skin rashes,
decreased absorption
of vitamins,
electrolyte
imbalances, lipid
pneumonia
Interactions
Toxicity and
Managing
Overdose
Decrease the
absorption of fatsoluble vitamins
(A,D,E and K)
Docusate salts (calcium and sodium) (Colace) are stool-softening
emollient laxatives that facilitate the passage of water and lipids (fats)
into the fecal mass, which softens the stool
Used to treat constipation, soften fecal impactions, and prevent opioidinduced constipation
Contraindicated in patients with intestinal obstruction, fecal impaction, or
nausea and vomiting
Mineral oil eases the passage of stool by lubricating the intestines and
preventing water from escaping the stool.
The only lubricant laxative in the emollient category
Most commonly used to treat constipation associated with hard stools or
fecal impaction
Contraindicated in patients with intestinal obstruction, abdominal pain, or
nausea and vomiting
Available as enemas and in products for oral use.
Hyperosmotic
Mechanism of Action
-Increase fecal water content
-Result in bowel distention, increased
peristalsis, and evacuation
Indications
Chronic constipation,
diagnostic and surgical
preps
Contraindications
Interactions
-Drug allergy
-Cautious use in the presence of the
following: Acute surgical abdomen,
appendicitis symptoms such as abdominal
pain, nausea, and vomiting , fecal impaction
(mineral oil enemas excepted); intestinal
obstruction; and undiagnosed abdominal pain
Increase depression of the
CNS if they are given w/
barbiturates, general
anesthetics, opioids, or
antipsychotics.
Glycerin




Lactulose




Polyethylene
Glycol 3350



Adverse Effect
Abdominal
bloating,
electrolyte
imbalances,
rectal irritation
Toxicity and
Managing
Overdose
Glycerin promotes bowel movement by increasing osmotic
pressure in the intestine, which draws fluid into the colon
It is a very mild laxative, it is often used in children
Contraindicated in patients who have a known hypersensitivity to it
Available as a rectal solution and as both adult and pediatric
suppositories.
A synthetic derivative of the natural sugar lactose, which is not
digested in the stomach or absorbed in the small bowel
This drug-induced acidic environment also reduces blood ammonia
levels by converting ammonia to ammonium.
Contraindicated in patients on a low-lactose diet.
Available as a solution for either oral or rectal use
PEG-3350 is most commonly given before diagnostic or surgi-cal
bowel procedures because it is a very potent laxative that induces
total cleansing of the bowel
Available in a powdered dosage form that contains mixtures of
electrolytes that also help stimulate bowel evacuation (e.g., Colyte,
GoLYTELY, MoviPrep, Half-Lytely).
Use of PEG is contraindicated in patients with GI obstruction,
gastric retention, bowel perforation, toxic colitis, toxic megacolon,
or ileus.

Diarrhea usually occurs within 30 to 60 minutes after ingestion;
complete evacuation and cleansing of the bowel is accomplished
within 4 hours
MiraLax is a PEG-3350 product that is available OTC and can be
used daily for constipation in much smaller amounts than those
used for total bowel cleansing.

Saline
Mechanism of Action
-Increased osmotic pressure
within GI tract, causing more
water to enter intestines
-Results in bowel distention,
increased peristalsis, and
evacuation

Magnesium
Salts


Indications
Adverse Effect
Constipation,
diagnostic and
surgical preps
Magnesium toxicity (with renal
insufficiency), cramping, electrolyte
imbalances, diarrhea, increased thirst
The magnesium saline laxatives, magnesium citrate (Citroma), and
magnesium hydroxide (Phillips Milk of Magnesia), are unpleasanttasting OTC laxative preparations
caution in patients with renal insufficiency because they can be
absorbed enough to cause hypermagnesemia
Most commonly used to evacuate the bowel rapidly in preparation for
endoscopic examination and to help remove unabsorbed poisons from
the GI tract.
Stimulant
Mechanism of Action
Indications
Adverse Effect
Increases peristalsis via
intestinal nerve
stimulation
Acute constipation,
diagnostic and surgical
prep
Nutrient malabsorption, skin rashes, gastric
irritation, electrolyte imbalances,
discolored urine, rectal irritation
Bisacodyl

Bisacodyl (Dulcolax) is the most commonly used stimulant laxative
Senna


Available as an oral tablet and rectal suppository.
Used for constipation or for whole bowel evacuation prior to endoscopic
examination.


Senna (Senokot) is a commonly used OTC stimulant laxative
Used for relief of acute constipation or bowel preparation for surgery or
examination
Because of its stimulating action on the GI tract, it may cause abdominal
pain
Produce complete bowel evacuation in 6 to 12 hours


Nursing Implications











Obtain a thorough history of presenting symptoms, elimination patterns, and allergies.
Assess fluid and electrolytes before initiating therapy.
Inform patients not to take a laxative or cathartic if they are experiencing nausea,
vomiting, or abdominal pain.
A healthy, high-fiber diet and increased
fluid intake should be encouraged as an alternative to laxative use.
Long-term use of laxatives often results in decreased bowel tone and may lead to
dependency.
All laxative tablets should be swallowed whole, not crushed or chewed, especially if
enteric coated
Patients should take all laxative tablets with
6 to 8 oz of water.
Patients should take bulk-forming laxatives as directed by the manufacturer with at
least
240 mL (8 oz) of water.
Give bisacodyl with water because of interactions with milk, antacids, and juices.
Inform patients to contact their prescribers if they experience severe abdominal pain,
muscle weakness, cramps, or dizziness, which may indicate possible fluid or
electrolyte loss.
Monitor for therapeutic effect
Drug for Irritable Bowel Syndrome
-Irritable bowel syndrome (IBS) is a condition of chronic intestinal discomfort characterized by cramps,
diarrhea, and/or constipation.
-Women are affected more often than men.
Irritable Bowel Syndrome
Indications
-Drugs used to treat IBS are divided into
those used to treat IBS with diarrhea
(IBS-D)
-Used to treat IBS with constipation
(IBS-C).
Adverse Effect
-Nutrient malabsorption, skin rashes, gastric
irritation, electrolyte imbalances, discolored urine,
rectal irritation
IBS-D (treat
diarrhea)
-There are 3 drugs :alosetron (Lotronex), rifaximin (Xifaxan), and
eluxadoline (Viberzi)
- Alosetron (Lotronex) is a selective serotonin 5-HT3 receptor antagonist
 Indicated: Treatment of severe, chronic, diarrhea-predominant IBS
in women who have failed conventional therapy. If response is
inadequate after 4 weeks, the drug is to be discon-tinued. It must be
discontinued immediately if constipation or signs of ischemic
colitis occur.
 Black box warning: regarding infrequent but serious GI adverse
reactions including ischemic colitis.
- Rifaximin is an antibiotic that works by reducing or altering bacteria in
the gut. It is only slightly absorbed and generally well tolerated.
-Eluxadoline is the newest drug for IBS-D.
IBS-C (treat
constipation)
-There are 2 drugs: lupriprostone (Amitiza) and linacotide (Linzess)
-Lubiprostone (Amitiza) is a chloride channel activator indicated for the
treat-ment of chronic idiopathic constipation and IBS-C constipation in
women 18 years of age and older.
 Adverse effects: nausea, diarrhea, and abdominal pain. It is
classified as a pregnancy category C drug Lubiprostone is
contraindicated in patients with known or suspected bowel
obstruction.
- Lina-clotide (Linzess) is a minimally absorbed peptide guanylate cyclaseC agonist.

Indicated: treatment of IBS-C and chronic idiopathic constipation.
 Contraindicated: patients with GI obstruction and in children
younger than 17 years of age.
 Side effects: include diarrhea, which can be serious, abdominal
pain, and flatulence.
-It is available as an oral capsule, which should be taken on an empty
stomach.
Chapter 52: Antiemetic and Antinausea Drugs
1. Discuss the pathophysiology of nausea and vomiting, including specific precipitating
factors and/or diseases.
Emesis: AKA Vomiting, forcible emptying or expulsion of gastric and, occasionally, intestinal
contents through the mouth. A variety of stimuli can induce nausea and vomiting, including foul
odors or tastes, unpleasant sights, irritation of the stomach or intestines, and certain drugs
Vomiting center: is an area in the brain that is responsible for initiating the physiologic events
that lead to nausea and vomiting.
Chemoreceptor trigger zone (CTZ): where neurotransmitter signals are sent to the vomiting
center. Once the CTZ and vomiting center are stimulated, they initiate the events that trigger the
vomiting reflex
2 specific types of nausea and vomiting, chemotherapy-induced and postoperative
2. Identify the various antiemetic and antinausea drugs and their drug classification
groupings.
ANTIEMETIC DRUGS
Mechanism of Action

Anticholinergic
Drugs: binding to and
blocking acetylcholine
(ACh) receptors in the
vestibular nuclei.

Antihistamine: Block
H1
receptors, thereby
preventing ACh from
binding to receptors in
the vestibular nuclei.
Indications

Anticholinergic
Drugs: Motion
sickness, secretion
reduction before
surgery, nausea and
vomiting.

Antihistamine:
Motion sickness,
nonproductive cough,
sedation, rhinitis,
allergy symptoms,
nausea and vomiting.
Adverse Effect

Anticholinergic
Drugs: Dizziness,
drowsiness,
disorientation,
tachycardia
, blurred vision,
dilated pupils, dry
mouth, difficult
urination, constipation
rash, erythema.

Antihistamine:
Dizziness, drowsiness,
confusion, blurred
vision, dilated pupils,
dry mouth, urinary
retention.





Antidopaminergic
Drugs: blocking
dopamine receptors in
the CTZ.
Neurokinin
receptor antagonists
: Inhibit the substance
P–neurokinin
receptors.
Prokinetics: Block
dopamine in the CTZ
or stimulate ACh
receptors in the GI
tract.
Serotonin blockers:
Block serotonin
receptors in the GI
tract, CTZ, and VC.
Tetrahydrocannabin
oids: Have inhibitory
effects on the reticular
formation, thalamus,
and cerebral cortex



Antidopaminergic
Drugs: Psychotic
disorders (mania,
schizophrenia,
anxiety), intractable
hiccups, nausea and
vomiting.

Antidopaminergic
Drugs: Orthostatic
hypotension,
tachycardia,
extrapyramidal
symptoms, tardive
dyskinesia, headache,
blurred vision, dry
eyes, urinary
retention, dry mouth,
nausea and vomiting,
anorexia, constipation

Neurokinin receptor
antagonists:
Hypotension,
bradycardia Fatigue,
dizziness
diarrhea, dyspepsia,
abdominal pain,
gastritis

Prokinetics:
Hypotension,
supraventricular
tachycardia
, sedation, fatigue,
restlessness, headache,
dystonia, dry mouth,
nausea and vomiting,
diarrhea.

Serotonin blockers:
Headache diarrhea,
rash, bronchospasm,
prolonged QT
interval
Neurokinin receptor
antagonists: Acute
and delayed vomiting
associated with
chemotherapy
Prokinetics: Delayed
gastric emptying,
gastroesophageal
reflux, nausea and
vomiting.

Serotonin blockers:
Nausea and vomiting
associated with
chemotherapy,
postoperative nausea
and vomiting.

Tetrahydrocannabin
oids: Nausea and
vomiting associated
with chemotherapy,
anorexia associated
with weight loss in
patients with AIDS
and cancer

Contraindications
-KDA
Interactions



Tetrahydrocannabin
oids: Drowsiness,
dizziness, anxiety,
confusion, euphoria,
visual disturbances,
dry mouth
Toxicity and Managing
Overdose
Anticholinergics have Possible addictive toxicity
additive drying effects may occur
when given with
antihistamines and
antidepressants.
Increased CNS
depressant effects are
seen when
antihistamine
antiemetics are
administered with
barbiturates, opioids,
hypnotics, tricyclic
antidepressants, or
alcohol
Neurokinin
antagonists
(aprepitant) may
induce the metabolism
of warfarin and may
reduce the effectiveness of oral
contraceptives
3. Describe the mechanisms of action, indications for use, contraindications, cautions, and
drug interactions of the various categories of antiemetic and antinausea drugs.
Anticholinergic - scopolamine
Mechanism of Action




Indications

It has potent effects on the
vestibular nuclei, located in
the area of the brain that
controls balance.
Scopolamine works by
blocking the binding of ACh
to the cholinergic receptors
in this region and thereby
correcting an imbalance
between the two
neurotransmitters ACh and
norepinephrine.
Scopolamine is available in
oral, injectable, transdermal,
and even ocular forms
most commonly used
formulation for nausea is the
72-hour transdermal patch

Contraindications

Scopolamine is one of
the most commonly
used drugs for the
treatment and
prevention of the
nausea and vomiting
associated with
motion sickness.
Scopol-amine is also
used to treat
postoperative nausea
and vomiting.
contraindicated
in patients with
glaucoma.
Antihistamine - meclizine
Indications

Contraindications
commonly used to treat the dizziness, vertigo, and nausea
and vomiting associated with motion sickness.


Shock
Lactation
Antidopaminergics - Droperidol
Mechanism of Action

black box warning and
required continuous
electrocardiographic
monitoring with its use.
Indications


widely used to treat
and prevent
postoperative
nausea and
vomiting for several
decades
Some health care
institutions still use
droperidol, whereas
Adverse Effect

concerns over
widening of the QT
interval and
possible ventricular
dysrhythmias.
others have banned
its use.
Antidopaminergics - promethazine
Mechanism of Action
Adverse Effect

Contraindications

Children younger
than 2 years of age
Sedation is the most common adverse effect and actually
may be beneficial.
Toxicity and Managing Overdose


Therapy must be discontinued immediately if burning or
pain occurs with administration.
If promethazine is inadvertently given intra-arterially
instead of intravenously, severe tissue damage, often
requiring amputation, can occur.
Neurokinin Receptor Antagonists - Aprepitant
Mechanism of Action


Is an antagonist of
substance P–
neurokinin 1
receptors in the
brain.
has little affinity for
5-HT3 (serotonin)
and dopamine
receptors.
Indications



Contraindications

pregnancy category
B drug
prevention of nausea and
vomiting associated with highly
emetogenic cancer chemotherapy
regimens, including high-dose
cisplatin
postoperative
nausea vomiting.
Interactions



Induce the metabolism of
warfarin
Reduce the effectiveness of oral
contraceptives.
Azole antifungals
Adverse Effect




Dizziness
Headache
Insomnia
GI
discomfort
Toxicity and
Managing
Overdose






Clarithromycin
Diltiazem
Nicardipine
Protease inhibitors
Verapamil
Increase the bioavailability of
corticosteroids
Prokinetic Drugs - metoclopramide
Mechanism of Action

Indications

Meto-clopramide is used
for the treatment of
delayed gastric emptying
and gastroesophageal
reflux and also as an
antiemetic
Adverse Effect



Contraindications




Interactions
Cause severe
adverse effects if not
used correctly
Extrapyramidal
adverse effects can
occur with its use,
especially in young
adults.
Potential for the
development of
tardive dyskinesia
with long-term use
Toxicity and Managing
Overdose
Seizure disorder,
pheochro-mocytoma
Breast cancer
GI obstruction
Patients with a
known
hypersensitivity to it
or to procaine or
procainamide
Serotonin Blockers - ondansetron
Mechanism of Action
Indications
Contraindications



5-HT3 receptor blockers
because they block the 5HT3
receptors in the GI tract,
the CTZ,
and the vomiting center.
Given approximately 30
minutes before the end of
the surgical procedure
Oral and injectable forms



Prevention of nausea and
vomiting associated with
cancer chemotherapy
Prevention of
postoperative or radiationinduced nausea and
vomiting.
Treatment of hyperemesis
gravidarum

Known drug
allergy.
Tetrahydrocannabinol - dronabinol
Mechanism of Action

Synthetic
derivative of THC,
the major active
substance in
marijuana.
Indications


Adverse effect
Treatment of nausea
and vomiting
associated with cancer
chemotherapy.
Second-line drugs after
treatment with other
antiemetics have
failed.

Stimulate appetite and
weight gain in patients
with AIDS and in
chemotherapy patients.
Miscellaneous Anti Nausea Drugs- phosphorated carbohydrate solution
Mechanism of Action


Synthetic derivative of THC, the
major active substance in marijuana.
Direct local action on the walls of the
GI tract, where it reduces cramping
caused by excessive smooth muscle
contraction.
Indications



Pleasant-tasting oral solution used to
relieve nausea =) (5 minutes for
advertisement)
Used is for the treatment of morning
sickness during pregnancy.
Not sufficient for treatment of more
severe nausea symptoms such as those
associated with cancer chemotherapy.
4. Develop a nursing care plan that includes all phases of the nursing process for patients
taking antiemetic and antinausea drugs.

Obtain a complete nursing history and perform a thorough physical assessment







Altered food, fluids and nutrients, decreased intake, related to the nausea from disease
pathology and adverse effects of specific groups of medications
Altered physical activity, impaired, related to adverse effects (e.g., sedation, lethargy,
confusion) of antiemetics
Altered safety needs, risk for injury (falls), related to the adverse effects of antiemetic
medications (e.g., sedation and dizziness
Administer intramuscular forms into large muscles (e.g., ventral, gluteal), and rotate sites
if repeated injections are necessary
Dry mouth, another adverse effect, produced by any of these medications may be
alleviated by using sugarless gum or hard candy
Monitor the patient for adverse effects such as GI upset, drowsiness, lethargy, weakness,
extrapyramidal reactions, and orthostatic hypotension during antiemetic therapy.
Laboratory testing (e.g., electrolyte levels, blood urea nitrogen level, urinalysis with
specific gravity) may be ordered for evaluation purposes
Chapter 41: Antitubercular Drugs
Antitubercular drugs: Drugs used to treat infections caused by Mycobacterium bacterial species.
1. Identify the various first-line and second-line drugs indicated for the treatment of
tuberculosis.
Antitubercular Drugs
Mechanism of Action


Inhibiting protein synthesis
(kanamycin, capreomycin,
rifabutin, rifampin,
streptomycin)
Inhibiting cell wall synthesis
(cycloserine, ethionamide,
isoniazid)
Indications



Contraindications


Severe drug allergy
Major renal or liver
dysfunction
Treatment of TB infections,
including both pulmonary
and extrapulmonary TB.
Management of treatment
failures and relapses
Infection with species of
Mycobacterium
Interactions
below
Adverse Effect
below
Toxicity and
Managing
Overdose
below


The combination of isoniazid and ethambutol has been used to treat pregnant
women without teratogenic complications.
Rifampin is another drug that is usually safe during pregnancy and is a more likely
choice for more advanced disease.
2. Discuss the mechanisms of action, dosages, adverse effects, routes of administration,
special dosing considerations, cautions, contraindications, and drug interactions of the
various antitubercular drugs.
Drugs
Description
Bedaquiline
(Sirturo)
_ Indication: treatment of multidrug-resistant TB
_ MOA: inhibits mycobacterial ATP synthase
_ Side effects: headache, chest pain, nausea, and QT prolongation
_ Contraindication: alcohol, mifepristone, strong CYP3A4 inhibitors,
and drugs with high risk for causing QT prolongation
*Administration with food significantly increases bedaquiline
absorption and should be given with food to aid in its absorption
*black box warning regarding QT prolongation & pregnancy category
B drug.
Ethambutol
(Myambutol)
_ Indication: first-line bacteriostatic drug used in the treatment of TB
_ MOA: diffusing into the mycobacteria and suppressing ribonucleic
acid (RNA) synthesis -> inhibits protein synthesis
_ Contraindication: patients with known optic neuritis -> vision loss.
Children younger than 13 years of age
*Ethambutol is included with isoniazid, streptomycin, and rifampin in
many TB combination-drug therapies
Isoniazid (also
called INH)
_ Indication: mainstay in the treatment of TB and the most widely used
antitubercular drug
_ MOA: a bactericidal drug that kills the mycobacteria by disrupting
cell wall synthesis and essential cellular functions
_ A/E: numbness/tingling of extremities, abdominal pain, jaundice, and
visual changes
_ Contraindication: previous isoniazid-associated hepatic injury or
any acute liver disease
*black box warning regarding possible hepatitis
*causing pyridoxine deficiency -> must supplements of pyridoxine
(vitamin B6 )
*cause false-positive readings on urine glucose tests (e.g., Clinitest) and
an increase in the serum levels of the liver function enzymes
Pyrazinamide (also _ Indication: combination with other antitubercular drugs for the
treatment of TB
called PZA)
_ MOA: inhibiting lipid and nucleic acid synthesis in the mycobacteria
_ Contraindication: severe hepatic disease or acute gout, pregnancy
Rifabutin
_ Indication: first-line TB, treat infections caused by M. aviumintracellulare complex, which includes several non-TB mycobacterial
species
_ Side effects: turn the urine, feces, saliva, skin, sputum, sweat, and
tears a red-orange-brown color.
Rifampin (Rifadin) _ Indication: used either alone in the prevention of TB or in
combination with other antitubercular drugs in its treatment.
_ Side effects: skin, sweat, tears, urine, feces, sputum, saliva, and
tongue to be red-orange-brown colored
_ A/E: hepatitis and/or various hematologic disorders ( fever, nausea,
vomiting, loss of appetite, jaundice, and/or unusual bleeding)
_ Contraindication: patients with known drug allergy to it or to any
other rifamycin (i.e., rifabutin, rifapentine)
*Women taking oral contraceptives who are prescribed rifampin must
be switched to another form of birth control. Oral contraceptives
become ineffective when given with rifampin.
Rifapentine
(Priftin)
*Indication, side effects, and contraindications same w Rifabutin &
Rifampin
*advantages over rifampin in that it has a much longer duration of
action and possibly better efficacy.
*greater antimycobacterial efficacy and macrophage penetration.
Streptomycin
_ Indication: was the very first drug available that could effectively
treat TB.
_ Contraindication: pregnancy
*Because of its toxicities, it is used most commonly in combination
drug regimens for the treatment of multidrug-resistant TB infections
3. Develop a nursing care plan that includes all phases of the nursing process for patients
receiving antitubercular drugs.
Assessment
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Head-to-toe physical assessment. Note any specific history of
diagnoses or symptoms of TB
The patient’s last purified protein derivative (PPD) or tuberculin
skin test and the reaction at the intradermal injection site
Recent chest x-ray and results
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Planning
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Implementation
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Evaluation
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Liver & kidney function ( because major liver and/or renal
dysfunction are contraindications )
Assessment of age is also important because the likelihood of
adverse reactions and toxicity is increased in older adult patients
due to age-related liver and kidney dysfunction
Assess the patient’s CBC prior to giving isoniazid, streptomycin,
and rifampin because of the potential for drug-related hematologic
disorders
Remains free of injury and experiences improved therapeutic
regimen management with compliance to regimen and
understanding about method of spread and improved
symptomatology.
Patient’s perception remains intact with the increase of knowledge
about antitubercular medication therapy and takes medication
regularly and for the length of time prescribed with reporting of
adverse effects and/or relapse in symptoms.
Patient remains free from injury related to compliance with
antitubercular drug regimen.
All antitubercular drugs need to be taken exactly as ordered and at
the same time every day.
Consistent use and dosing around the clock are critical to
maintaining steady blood levels and minimizing the chances of
resistance to the drug therapy
The entire prescription must be finished over the prescribed time
and as ordered by the prescriber, even if the patient is feeling better.
To be taken with food to minimize gastrointestinal upset.
Constantly monitor for any signs and symptoms of liver dysfunction
such as fatigue, jaundice, nausea, vomiting, dark urine, and
anorexia. If these occur, contact the prescriber immediately
Monitor kidney function (e.g., BUN, creatinine), and notify the
prescriber if levels are altered.
If vision changes occur (e.g., altered color perception, changes in
visual acuity),
must be reported immediately to the prescriber
Monitor uric acid levels during therapy, and advise the patient to
report any symptoms of gout such as hot, painful, or swollen joints
of the big toe, knee, or ankle
The prescriber must be notified if there are signs and symptoms of
peripheral neuropathy (e.g., numbness, burning, and tingling of
extremities)
monitor patients for the occurrence of adverse reactions to
antitubercular drugs, such as hearing loss (ototoxicity);
nephrotoxicity; seizure activity; altered vision; blindness; extreme
gastrointestinal (GI) upset; fatigue; nausea; vomiting; fever;
jaundice; numbness, tingling, or burning of the extremities;
abdominal pain; and easy bruising.
4. Develop a comprehensive teaching guide for patients and families impacted by the
diagnosis and treatment of antitubercular drugs.
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Instruct the patient to avoid certain medications while taking antitubercular drugs, such
as:
antacids
phenytoin
carbamazepine
beta blockers
benzodi-azepines
oral anticoagulants
oral antidiabetic drugs
oral contraceptives
theophylline
Encourage the patient to wear sunscreen and protective clothing during therapy to
avoid ultraviolet light exposure.