introduction

Introduction to Pharmacology

د. شامل هاشم ألنعيمي
بكالوريوس طب وجراحة
ماجستير سموم
دكتوراه أدوية

Objectives:

At the end of this lecture, the students will be able to:

1.Define some pharmacological terms

2. List the major factors that determine the properties of ideal drug
3. Compare between potency and efficacy.

4.List the factors that determine the intensity of drug response

Drug: A drug is a chemical that affects physiological and biochemical functions in a specific way.


Pharmacology: can be defined as the study of drugs and their interactions with living systems.

Study the physical and chemical properties of drugs as well as their biochemical and physiological effects.

Clinical pharmacology: The use of drugs to diagnose, prevent or treat diseases. Or simply is the medical use of drugs.

Toxicology: It is part of pharmacology which deals with the undesired or toxic effect of drugs.

Pharmacy: It is the science that deals with preparing and dispensing drugs ( medicines)

Pharmacogenetic: It is the science that concern with drug response that are governed by heredity.

EffectivenessSafetySelectivityReversible action

Properties of an Ideal Drug

Ease of administrationFreedom from drug InteractionsLow costChemical Stability

Efficacy: is the capacity of a drug to produce a specific effect.

e.g.1 Meperidine vs pentazocine

e.g. 2 Amiloride vs Bendrofluazide

Potency: Refers to the amount of drug (in weight) that elicit an effect.

e.g. Morphine 10mg can relief severe pain , meperidine 100 mg can relief the same degree of pain relived by morphine, so morphine is more potent than meperidine.

Prescribed doseAdministered doseConcentration at sites of action

Factors that determine the intensity of drug responses

Administration: Medication Errors and Patient compliance

Pharmacokinetics processes.

Individual Variations: Physiological variables, Pathological variables, genetic variables and drug interactions.

Pharmacodynamics: Drug receptor interaction and patient functional state.

Sources of Individual Variations:

Drug interaction
Physiologic variables: age, sex, weight, obesity

Pathological variables: Diminished function of the liver and kidney

Genetic variables: May alter the metabolism of drugs ( defect of enzymes of metabolism).

Study Question

Which is more important, Efficacy or Potency? Why?