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Introduction to Pharmacology

N319 Introduction to Pharmacology
1. History of Pharmacology
John Jacob Abel
2. Sources of medications
-Alkaloids, Glycosides, Gums, Oils
Chemicals- primary source today
3. Pharmacology the study of medicines
4. Pharmacology and Therapeutics
5. Drug Classifications
Complementary and Alternative
6. Therapeutic and pharmacologic classification of drugs
Therapeutic classification
Pharmacologic classification
7. Names of drugs
Chemical- chemical composition
Generic- universal name
Trade/Brand- assigned by the manufacturer once released on the market
8. Types of drug therapyPrescription drugs
Nonprescription drugs
Controlled drugs
Recreational drugs
9. Trade vs Generic drugs
10. Drug Approval
Intro 1
1906— Pure Food and Drug Act: protected the public from mislabeled products
1938— Food Drug & Cosmetic Act: made sure there was no harmful effects
1951— Durham-Humphrey Amendment to FDCA: separated prescription vs nonprescription drugs
1970— Controlled Substance Act (know table 2.1): created 5 schedules for controlled substances
1983— Orphan Drug Act: funds were given to companies to research drugs that were uncommon
1997— Food and Drug Modernization Act: Fast track system, off-label uses of drugs, use of children
in studies. Black Box Warnings
2003-- Health Insurance Portability and Accountability Act (HIPAA): protected patient privacy
2010-- Patient Protection and Affordable Care Act: Obama Care
11. Regulatory Agencies
Food & Drug Administration (FDA): oversees all medications
Drug Enforcement Agency (DEA): controls all controlled substances
Centers for Disease Control (CDC): controls chemical warfare
American Nursing Association (ANA): regulates the nursing education and practice
State Board of Nursing
Nurse Practice Act
Misfeasance- when you give a wrong medicine or dose
Nonfeasance- when you forget to give a medication
Malfeasance- when you give the right drug in the wrong route
12. Sources of Drug Information
U.S. Pharmacopeia (USP)- USP Label. Drug must be of high standard to be listed. 3 volume set
published annually with 2 supplements. Information: strength, quality, purity, packaging, safety,
labeling, dosage form.
National Formulary- Supplement to the USP
PDR- Used by a variety of HCP. Lists pharmaceutical companies, color pictures of meds. Drug action,
recommended dosage, indications for use, side effects.
Nursing Drug Handbooks- Generic and trade names. Indication for use & recommended doses.
Action & pharmacokinetics. Side effects & nursing implications, teaching tips.
Internet- Action, indications, side effects, when to contact MD. May or may not be at patient’s level
of understanding. May not contain accurate information.
Pharmaceutical Companies- Drug samples, teaching handouts.
13. Drug development and approval
Pre-clinical testing- Extensive animal studies for safety, biological activity, and formulations
Submit Investigational New Drug (IND) application-Application reviewed by FDA
Clinical testing- Human studies (10 years or older)
Phase I- Studies the kinetics, determine safety, and dosage ranges of the drug on a small group
of healthy volunteers (20-100)
Phase 2- Evaluate effectiveness and identifies side effects of the drug on a small number of
individuals with the disease (100 to 500)
Phase 3- Studies the safety and efficacy of the drug on a large number of individuals with the
disease (1000 to 5000). Placebo-controlled studies, blind investigational drug studies, doubleblind placebo-controlled studies
Submit a new drug application (ND) to FDA
Phase 4- Post market studies-Long-term uses, additional uses
Intro 2
14. Informed Consent
Nuremburg Code- rights of human subjects to be protected in medical research
Informed Consent- Describes the study in detail. Hazards, risks, and benefits of study. Payment.
Study termination. Confidentiality
Role of the nurse- Inform the patient of all the details of the study
Basic Tasks for obtaining Informed Consent- Decision Making Capacity. Information/Education.
Understanding. Free-Choice. Obtain informed consent. Documentation.
15. Pregnancy and Lactation Label Changes
Letter categoriesRisk summary16. The Nursing Process
Assessment--Gather data:
Subjective- health history, drug history
Objective- physical exam, lab data, diagnostic tests
Nursing Diagnosis-NANDA List
Identify health care needs of clients- actual or potential within the realm of nursing practice
Nursing diagnosis related to drug therapy- Knowledge deficit, noncompliance, or diagnosis
related to side effects
Alteration in tissue perfusion r/t decrease oxygen supply to coronary arteries 20 to CAD
Knowledge deficit r/t diuretic therapy 20 to new tx regimen.
Planning (establishing goals)
S- specific to patient
M- measurable
A- attainable
R- realistic
T- time limited
Pt will lose 5# within 3 days
Pt will demonstrate proper administration techniques of medications prior to discharge
Knowledge necessary before administering drug therapy- Goals of drug therapy, Mechanism of
drug action, Expected effects, Proper administration techniques, Contraindications
Patient Education- Why are they taking it? What is the intended therapeutic response? How
should the medication be taken? How often should the medication be taken? What side effects
will occur and which to report to HCP?
Medication orders
Components of a Drug Order- date and time, patient name and hospital number, drug
name, dosage, route and frequency, MD name, nurses name and title
Prescriptions (# refills, duration, #dispense)
Types of Drug orders
Written orders vs Fax orders
Phone orders vs Verbal orders- must repeat to the provider
Standing order- MD has these for all patients; routine orders
Administration of medications
30-minute window
5 rights of medication administration- Right patient (identify by two methods), right drug,
right dose, right time, right route
Intro 3
Documentation- Date, time, med, dose, route
Withholding medication- Patient refuses, side effects. Notify physician and document; educate
the patient on effects of not taking the medication
Evaluations-Evaluate effectiveness of medications for therapeutic and non-therapeutic responses30 minutes to an hour after administering
Determine the extent to which goals of care have been achieved. How did the client respond to
the interventions?
Compare client response to outcome and document responses
Analyze reasons for results and conclusions
Modify care plan
Basic Principles of Pharmacology
1. 3 Phases of Drug Action
Pharmacokinetic Phase- what the body does to the drug
Pharmacodynamic Phase- what the drug does to the body
Pharmacotherapeutic Phase- side effects of the drugs
2. Pharmacodynamic Phase
What is pharmacodynamics? Describes the biochemical, physiologic action, and effects of drugs in
the body; occurs when the drug reaches its target cell, tissue, organ generating its effect; cannot create
a new response in the body
Frequency Distribution Curve
ED50- the average dose that produces half of the desired response on most patients
(recommended dose)
Objective measurements- antihypertensive drug; ED50 is the dose that reduces BP by one half
of the number of mmHg above normal (single patient)
Subjective measurements- Nausea medication; ED50 is the dose that produces relief of nausea
in half of the test subjects (100’s of subjects required)
LD50- produces death in one half of the test animals
Therapeutic Index- the middle of the ED50 and LD50; TI= LD50/ED50
Margin of Safety- TI provides a drug’s margin of safety; the wider the curve the safer the drug
Drug Response Curve
3 phases
Phase 1- lowest dosage range that produces a clinical response
Phase 2- increase in dosage produces an increased response
Phase 3- dosage effects have reached 100% of their therapeutic effects
Potency- the measurement of the amount of active ingredient of the drug; the drug with the least
amount of active ingredient producing its ED50 is more potent
Efficacy- the drugs ability to produce an effect; maximum efficacy is the maximum effect that a drug
can produce
Objective is to select drugs that have a very narrow and well-defined target or very specific action in
the body. The narrower the action, the less widespread damage (i.e., adverse effects).
Theories of Drug Action
Nonspecific Theory- Medications that influence and change the environment of cells.
Five mechanisms
Alteration of body chemistry (pH, osmotic pressure, electrolytes).
Absorption of toxins/drugs, electrolytes, bile salts, in the intestinal tract
Intro 4
Create a physical barrier
Lubricates cells
Alters surface tension
Drug Enzyme Theory- 2 forms of Drug-enzyme interaction
A drug may bind to the same physical location on the enzyme, preventing the enzyme from
functioning normally.
A drug may interact with an enzyme target changing the physical structure of the enzyme
and disrupting its integrity.
Drug Receptor Binding
Agonist Drugs- mimics the normal response of the natural chemical
Antagonist Drugs- blocks the natural chemical from binding which creates the opposite
effect of the normal response
Upregulation- more receptors; happens with antagonists
Downregulation- less receptors; happens with agonists
3. Pharmacotherapeutics
Types of therapy
Acute- New or immediate problem. (Appendicitis)
Maintenance- Maintains current functions, does not prevent progression. (Insulin, BP meds)
Supplemental- Maintains normal functions. (Vitamins, Protein drinks)
Supportive- Maintains body function integrity. (IV fluids)
Prophylactic- Preventive care. (Antibiotics prior to surgery)
Palliative- End of life care, comfort measures. (Pain medications)
Adverse Drug Reactions (ADRs)
TYPE A: Intrinsic Adverse Drug Reaction-A direct (excessive) extension of the known
pharmacodynamic actions. Intrinsic ADR's are the most common type of ADR (60-70% of all
known ADR's), predictable, and dose-dependent
Define the following Type A ADRs:
Toxic Reaction- Toxic Reactions are physical reactions resulting from exposure to a
poisonous chemical
Tachyphylaxis- rapidly diminishing response to successive doses of a drug, rendering it less
effective. The effect is common with drugs acting on the nervous system.
Drug Tolerance- A condition that occurs when the body gets used to a medicine so that
either more medicine is needed or different medicine is needed.
Additive/Synergistic Effects- occurs when the combined effect of two or more chemicals is
equal to the sum of the effect of each agents given alone
Antagonistic Effects- A biologic response to exposure to multiple substances that is less than
would be expected if the known effects of the individual substances were added together.
TYPE B: Idiosyncratic Adverse Drug Reaction -An uncommon, unpredictable ADR that is not
explained by pharmacodynamics, 20-30% of all ADR's, independent of the size of the dose of
drug administered, may be genetically linked.
Define the Following Type B ADRs:
Allergic reaction/Anaphylaxis- The hypersensitive response of the immune system of an
allergic individual to a substance. When an allergen enters the body, it causes the body's immune
system to develop an allergic reaction in a person with an allergy to it.
Idiosyncratic Response- adverse effects that cannot be explained by the known mechanisms
of action of the offending agent, do not occur at any dose in most patients, and develop mostly
unpredictably in susceptible individuals only.
Intro 5
Carcinogenic Effect- a chemical substance or a mixture of chemical substances which induce
cancer or increase its incidence.
Teratogenic Effect- the ability of a drug to cause fetal abnormalities or deformities.
Extrapyramidal Effect- describe the side effects caused by certain antipsychotic and other
drugs. These side effects include involuntary or uncontrollable movements. tremors.
Serum sickness- The immune system reacts to medicines that contain proteins used to treat
immune conditions. It can also react to antiserum, the liquid part of blood that contains antibodies given
to a person to help protect them against germs or poisonous substances.
Fetal alcohol Syndrome- a condition in a child that results from alcohol exposure during the
mother's pregnancy. Fetal alcohol syndrome causes brain damage and growth problems. The problems
caused by fetal alcohol syndrome vary from child to child, but defects caused by fetal alcohol syndrome
are not reversible.
Iatrogenic Reaction- Due to the activity of a physician or therapy. For example, an iatrogenic
illness is an illness that is caused by a medication or physician
Define the Following Terms
Photosensitivity- Oversensitivity of skin to light. Photosensitivity can be a side effect of
medications or result from diseases, such as lupus. Treatment depends on the severity of the reaction
and the cause. Photosensitivity can be prevented by avoiding skin exposure to ultraviolet light.
Incompatible- an undesirable reaction that occurs between the drug and the solution,
container or another drug
Polypharmacy- regular use of at least five medications, is common in older adults and
younger at-risk populations and increases the risk of adverse medical outcomes. There are several risk
factors that can lead to polypharmacy
Placebo- a pharmacologically inactive substance that can have a therapeutic effect if
administered to a patient who believes that he or she is receiving an effective treatment.
Intro 6