COAGULATION MODIFIER DRUGS
Lilley Reading and Workbook, Chap 27
COAGULATION MODIFIER DRUGS

Anticoagulants

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Antiplatelet drugs


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Inhibit platelet aggregation
Prevent platelet plugs
Thrombolytic drugs

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Inhibit the action or formation of clotting factors
Prevent clot formation
Lyse (break down) existing clots
Hemostatic or Antifibrinolytic drugs

Promote blood coagulation
HEMOSTASIS


The process that halts bleeding after injury to a
blood vessel
Complex relationship between substances that
promote clot formation and either inhibit
coagulation or dissolve a formed clot
ANTICOAGULANTS


Have no direct effect on a blood clot that is
already formed
Used prophylactically to prevent
Clot formation (thrombus)
 An embolus (dislodged clot)

COAGULATION SYSTEM


“Cascade”
Each activated factor serves as a catalyst that
amplifies the next reaction

Result is fibrin, a clot-forming substance

Intrinsic pathway and extrinsic pathway
ANTICOAGULANTS:
MECHANISM OF ACTION
Vary, depending on drug
 Work on different points of the clotting cascade
 Do not lyse existing clots
 Heparin
 & low-molecular-weight heparins enoxaparin (Lovenox)



Turn off coagulation pathway and prevent clot formation
Warfarin (Coumadin)
All ultimately prevent clot formation
ANTICOAGULANTS

Prevention of clot formation also prevents:
Stroke
 Myocardial infarction (MI)
 Deep vein thrombosis (DVT)
 Pulmonary embolism (PE)

ANTICOAGULANTS: INDICATIONS

Used to prevent clot formation in certain
settings where clot formation is likely
Stroke
 Atrial fibrillation
 Myocardial infarction (MI) / Unstable Angina
 Deep vein thrombosis (DVT)
 Pulmonary embolism (PE)
 Indwelling devices, such as mechanical heart valves
 Major orthopedic surgery

ANTICOAGULANTS:
ADVERSE EFFECTS

Bleeding
Risk increases with increased dosages
 May be localized or systemic


May also cause

Nausea, vomiting, abdominal cramps,
thrombocytopenia, others
ANTICOAGULANTS

Heparin

Monitored by activated partial thromboplastin
times (aPTTs)
Goal: Therapeutic range based on body weight based
dosage
 aPTT between 1.5 – 2.5 times normal control level

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Parenteral – IV bolus followed by infusion
Never mixed with any other medication
Short half-life (1 to 2 hours)
Effects reversed by protamine sulfate
Obtained from sheep, cows, and pigs
HEPARIN: NURSING IMPLICATIONS

Anticoagulant effects seen immediately

Laboratory values are done daily to monitor coagulation effects (aPTT)

Intravenous doses are usually double checked with another nurse

Ensure that SC doses are given SC, not IM


SC doses should be given in areas of deep subcutaneous fat, and sites
rotated
Bleeding precautions
ANTICOAGULANTS

Low-molecular-weight heparins
enoxaparin (Lovenox)
 dalteparin (Fragmin)


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More predictable anticoagulant response
Do not require frequent laboratory monitoring
Given subcutaneously – rotate sites
Patient may be instructed for home administration
Bleeding precautions
Protamine sulfate can be given as an antidote in case of
excessive anticoagulation
ANTICOAGULANTS

warfarin sodium (Coumadin)

Given orally only – usually late afternoon – same time daily

Monitored by INR (INR) - 2-4 depending on diagnosis
(Prothrombin time – lab-specific -- 1 ½ - 2 ½ times the control 12-15 sec)
 Dose changed according to INR results


phytonadione (Vitamin K) can be given if toxicity occurs
WARFARIN - NURSING IMPLICATIONS
Assess:
 Patient history, medication history, allergies
 Contraindications
 Baseline vital signs, laboratory values
 Potential drug interactions—there are MANY!
 History of abnormal bleeding conditions
 Usually started 2-3 days prior to heparin infusion being
discontinued - until PT-INR levels indicate adequate
anticoagulation

Full therapeutic effect takes several days
Monitor PT-INR regularly—keep follow-up appointments
 Antidote is phytonadione (Vitamin K)

WARFARIN -- NURSING IMPLICATIONS

Many herbal products have potential
interactions—increased bleeding may occur
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Capsicum pepper
Garlic
Ginger
Gingko
Ginseng
Feverfew
ANTIPLATELET DRUGS
Indications

Antithrombotic effects


Reduce risk of fatal and nonfatal strokes
Adverse effects

Vary according to drug
ANTIPLATELET DRUGS

Prevent platelet adhesion

Aspirin

dipyridamole (Persantine)

clopidogrel (Plavix) and ticlopidine (Ticlid)


ADP inhibitors
tirofiban (Aggrastat), eptifibatide (Integrilin)

New class, GP IIb/IIIa inhibitors
ANTIPLATELET DRUGS:
NURSING IMPLICATIONS
Concerns and teaching tips

Same as for Anticoagulants
Dipyridamole should be taken on an empty stomach
 Drug-drug interactions
 Adverse reactions to report
 Monitoring for abnormal bleeding

ANTIFIBRINOLYTIC DRUGS
Prevent the lysis of fibrin
 Results: promote clot formation
 Used for prevention and treatment of excessive
bleeding resulting from hyperfibrinolysis or
surgical complications

aminocaproic acid (Amicar)
 desmopressin (DDAVP)



Similar to ADH
Also used in the treatment of diabetes insipidus
ANTIFIBRINOLYTIC DRUGS:
INDICATIONS

Prevention and treatment of excessive
bleeding



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Hyperfibrinolysis
Surgical complications
Excessive oozing from surgical sites such as chest
tubes
Reducing total blood loss and duration of bleeding in
the postoperative period
ANTIFIBRINOLYTIC DRUGS:
ADVERSE EFFECTS

Uncommon and mild

Rare reports of thrombotic events

Others include:

Dysrhythmia, orthostatic hypotension, bradycardia,
headache, dizziness, fatigue, nausea, vomiting,
abdominal cramps, diarrhea, others
THROMBOLYTIC DRUGS

Drugs that break down, or lyse, preformed clots

Older drugs


streptokinase and urokinase
Newer drugs
Tissue plasminogen activator (TPA)
 Anisoylated plasminogen-streptokinase
activator complex (APSAC)

THROMBOLYTIC DRUGS (CONT’D)
streptokinase (Streptase)
 anistreplase (Eminase)
 alteplase (t-PA, Activase)
 reteplase (Retavase)
 tenecteplase (TNKase)
 drotrecogin alfa (Xigris)

THROMBOLYTIC DRUGS:
MECHANISM OF ACTION



Activate the fibrinolytic system to break down the
clot in the blood vessel quickly
Activate plasminogen and convert it to plasmin,
which can digest fibrin
Reestablish blood flow to the heart muscle via
coronary arteries, preventing tissue destruction
THROMBOLYTIC DRUGS:
INDICATIONS
Acute MI
 Arterial thrombolysis
 DVT
 Occlusion of shunts or catheters
 Pulmonary embolus
 Acute ischemic stroke – Code Green

THROMBOLYTIC DRUGS:
ADVERSE EFFECTS

BLEEDING
Internal
 Intracranial
 Superficial


Other effects
Nausea, vomiting, hypotension, anaphylactoid reactions
 Cardiac dysrhythmias

NURSING IMPLICATIONS
Assess:
Patient history, medication history, allergies
 Contraindications
 Baseline vital signs, laboratory values
 Potential drug interactions—there are MANY!
 History of abnormal bleeding conditions

THROMBOLYTIC DRUGS:
NURSING IMPLICATIONS

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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 (decreased
BP, restlessness, increased pulse)
ANTICOAGULANTS:
PATIENT EDUCATION
Education should include:
Importance of regular lab testing
 Signs of abnormal bleeding
 Measures to prevent bruising, bleeding, or tissue
injury
 Wearing a medical alert bracelet
 Avoiding foods high in vitamin K (tomatoes, dark
leafy green vegetables)
 Consulting physician before taking other meds or
OTC products, including herbals

COAGULATION MODIFIER DRUGS
NURSING IMPLICATIONS

Monitor for therapeutic effects

Monitor for signs of excessive bleeding


Bleeding of gums while brushing teeth, unexplained
nosebleeds, heavier menstrual bleeding, bloody or tarry
stools, bloody urine or sputum, abdominal pain,
vomiting blood
Monitor for adverse effects

Increased BP, headache, hematoma formation,
hemorrhage, shortness of breath, chills, fever
REVIEW
Antiplatelet agents act by:
1. preventing extension of existing clots.
2. preventing platelets from uniting.
3. dissolving existing clots.
4. increasing blood viscosity.
REVIEW
Doses of heparin are based on what laboratory
report?
1. warfarin serum level
2. activated partial thromboplastin time
(APTT)
3. Lee White clotting time
4. prothrombin time (PT) and INR
REVIEW
Nursing responsibilities involved in the
administration of heparin subcutaneously
include:
1. checking calculations with a second
qualified nurse.
2. using a 20-gauge needle to inject the
drug.
3. injecting the drug deep intramuscularly
(IM).
4. aspirating before injecting the drug.
REVIEW
Clopidogrel (Plavix) is used to:
1. dissolve existing arterial blood clots.
2. prevent further movement of an embolus.
3. prevent platelet aggregation.
4. prevent extension of an existing
thrombus.