Administration of Medication

3. “One of the features which is
thought to distinguish man
from other animals is his
desire to take medicines”
(Sir William Osler, 1849-1919)

4. PHARMACOLOGY
• The study of the effects of drugs on living
organisms.

5. • A drug is any substance that
alters physiological function,
with the potential for affecting
health.
• Medication may be defined as a
substance used to promote
health, to prevent illness, to
diagnose, to alleviate or cure
diseases.

6. • A medication is a drug
administered for its
therapeutic effects.
• Thus, all medications are
drugs, but not all drugs are
medications.

7. DEFINITIONS
• Pharmacology:- is the science of the interaction of
chemicals with living systems at all levels.
• Pharmacokinetics:- sometimes abbreviated as PK,
(from Ancient Greek pharmakon "drug“
and kinetikos "to do with motion"; ) investigates the
effects of the biological system on drugs (absorption,
distribution, elimination…) or what the body does to
the drug.
• Pharmacodynamics:- describes the fundamental
action of a drug on a physiological, biochemical or
molecular level or what the drug does to the body.

8. • Pharmacogenetics:- examines the
effects of genetic factors to variations in
the drug response (“Asian Flush”, Codeine
“resistance”)
• Toxicology:- studies the undesirable
effects of chemicals on living systems
(includes poisons, antidotes and unwanted
side effects of drugs)
• Pharmacy:- is the art of preparing,
compounding and dispensing chemicals
for medicinal use

9. Definitions
• Prophylactic refers to a drug or procedure aimed to
prevent disease
• Palliative refers to a drug or procedure aimed to relieve
symptoms
• Therapeutic refers to a drug or procedure aimed to
cure disease
• Tolerance is the increased resistance to the usual
effects of an established dose of a particular drug

10. • Effective dose (ED50):- is the concentration at which
50% of the subject show a predefined response.
• Efficacy:- refers to the inherent capability of a drug to
produce a desired effect.
• Potency:- compares the relative effectiveness of drugs
to produce a desired effect e.g. Drug A requires fewer
milligrams than Drug B to achieve the same
pharmacological response.
--> Drug A has the higher potency, yet, both drugs
have the same efficacy.
Definitions

11. HISTORY OF PHARMACOLOGY
• Origins
– Plants
– Animals

12. Pharmacognosy
Pharmacokinetics
Pharmacodynamics
PharmacotherapeuticsToxicology
Science
of Pharmacology

13. 5 Branches of Pharmacology
1. Pharmacognosy - Origin
2. Pharmacokinetics - Movement through
Body
3. Pharmacodynamics - Effect
4. Pharmacotherapeutics - Use/Purpose
5. Toxicology -Side Effects

14. Terminology for Patients
• Drug (medication)
– pharmacological agent
– produces biological effect
• Prescription Drug
– safe under supervision
– prescribed by licensed practitioner

16. Terminology (con’t)
• Non-Prescription (Over-the-Counter or
OTC)
– safe if instructions followed
– no prescription necessary

19. Terminology (con’t)
• Recreational Drug
– use for pleasant psychological/physical
effects
– no therapeutic intent

20. Terms Relating to Drug Action
• ONSET OF ACTION (the time it takes for
the body to respond to a drug after
administration).
• PEAK PLASMA LEVEL (the highest
blood concentration of a single drug dose
before the elimination rate equals the rate
of absorption).
• PLATEAU (maintenance of a certain
level).

21. Resources for Drug Information
• Pharmacopedia
– Official resource
– US Pharmacopedia, British Pharmacopedia

22. Resources (con’t)
• Compendia
– Non Official
– American Formulary, Facts & Comparisons,
USP Dispensing
• Pharmaceutical Firms
– Physician’s Desk Reference (PDR)
– PDR for OTC
– Package inserts

23. Resources (con’t)
• Journals
– Nursing 2011
– AJN
– RN
• Nursing Reference Books
• Web sites
– WebMD
– Epocrates

24. Nurse Practice Act
• Each state has own regulations
• RN may not prescribe or administer Rx
without MD order

25. DRUG STANDARDS AND LEGISLATION
• A drug is a chemical substance intended
to elicit a specific effect.
• Standards are set to ensure drug
uniformity in:
– Strength.
– Purity.
– Efficacy.
– Safety.
– Bioavailability (amount of absorbed drug in blood).

26. STANDARDS
• The United States Pharmacopeia, the
Indian Pharmacopeia and the British
Pharmacopeia (USP, IP and BP) are
standard formularies for drug preparation,
packaging, marketing and dispensing in
India.

27. Legislation: The FDA
• The Food and Drug Administration
(FDA) and Drug controller of India
(DCI) tests all drugs for toxicity
before granting a company the right
to market a drug.

28. New Drug Development
• FDA monitors process
• Animal Trials
• Human Trials
– first healthy clients
– next small # of clients with the disease
– next large # of clients with disease
– on going reporting of side effect

29. Drug Nomenclature
• Drugs are usually referred to by their
generic name (not capitalized) or by their
trade name (always capitalized).

30. Drug Nomenclature (Names)
• Chemical Name
– atomic/molecular structure
• Generic Name (OFFICIAL)
– derived from chemical name
– listed in US Pharmacopedia & Formulary
• Trade Name (Brand)
– selected by Manufacturer
– copyrighted

31. Drug Nomenclature (Names)
Chemical
Name
Generic Name Trade Name
7-chloro-1,3-dihydro-1-
methyl-5 phenyl 2H-1,
4-benzodiazepin 2-one
diazepam Valium
Ethyl 1-methyl 4-pheyli-
sonipecotate
hydrochloride
meperidine Demerol
acetylsalicyclic aspirin Ecotrin

32. Drug Action
• A drug’s ability to combine with a cellular
drug receptor.
• Depending on the location of the cellular
receptor, the drug can have a local effect,
a systemic effect, or both.

33. PHARMACOKINETICS
• For a drug to achieve a therapeutic effect, it must
proceed from the point of entry into the body to the
tissue with which it will react.
• The effectiveness is further affected by the dosage of
the drug and the amount of time the drug spends in the
body before it is excreted.
• Pharmacokinetics refers to the study of the
absorption, distribution, metabolism, and excretion of
drugs to determine the relationship between the dose of
a drug and the drug’s concentration in biological fluids.
• Drug actions are dependent on four properties:
absorption, distribution, metabolism, and excretion.

34. Pharmacokinetics
• Absorption
• Distribution
• Metabolism
• Excretion

35. Absorption
• Depends on route
• Enteral - GI system (p.o., SL, PR)
• Parenteral - Injected (ID, SQ, IM, IV)

36. The 4 Properties of Drug Action
The ADME scheme (also referred to as LADME if liberation is included as a
separate step from absorption):
• LIBERATION - the process of release of a drug from the pharmaceutical
formulation.
• ABSORPTION (passage of a drug from the site of administration
into the bloodstream).
• DISTRIBUTION (the movement of drugs from the blood into body
fluids and tissues).
• METABOLISM (the physical and chemical processing of a drug by
the body).
• EXCRETION (the elimination of drugs from the body.

37. DRUG INTERACTION
• The effect one drug can have on another
drug.

38. Food and Drug Interactions
• Certain drugs may interfere with the
absorption, excretion, or use in the body
of one or more nutrients.
• Certain foods may increase or decrease
the absorption of a drug into the body.
• Other foods may alter the chemical
actions of drugs, preventing their
therapeutic effect on the body.

39. Side Effects and Adverse
Reactions
• Drug Allergy.
• Drug Tolerance.
• Toxic Effect.
• Idiosyncratic Reaction.

40. • A Side Effect is an effect, whether
therapeutic or adverse, that is
secondary to the one intended;
although the term is predominantly
employed to describe Adverse
Effects, it can also apply to
beneficial, but unintended,
consequences of the use of a drug.

41. Factors Influencing Drug Action
• Genetic factors.
• Age.
• Height.
• Weight.
• Physical
conditions.
• Mental conditions.