This document defines key terms and concepts in pharmacology. It discusses how pharmacology is the study of drug interactions with living systems. The four main processes that determine a drug's effects are absorption, distribution, metabolism, and excretion. Factors like genetics, age, and health conditions can influence how individuals respond to drugs. Adverse reactions, drug interactions, and tolerance are important considerations when using medications. Standards and regulations aim to ensure drugs are safe, effective, and produced consistently.

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.