PHARMACOLOGY oScience of drugs oGreek words= pharmakon (drug) and logos (study) oDeals with interaction of exogenously administered chemical molecules with living system

 All aspects of the study of drugs including drug development, drug- biological system interaction, therapeutics and toxicology

HISTORICAL BACKGROUND  Recent branch of medical science ~ 100 y old  World’s oldest pharmacological or therapeutic writing come from China and India

BRANCHES/DIVISIONS OF PHARMACOLOGY 1)Pharmcodynamics (Greek:dynamis, power) Deals with biological effects (pharmacologic and toxic) and mechanism of action of the drug

2) Pharmacokinetics (Greek:kinesis, movement) Refers to movement of the drug in, through and out of the body to achieve drug action Four major processes; absorption, distribution, biotransformation and excretion

3) Pharmcotherapeutics  Application of pharmacological information together with knowledge of the disease for its prevention or cure i.e. use of drugs in treatment of disease 4) Clinical pharmacology  Scientific study of drugs in man  Pharmacodynamics and pharmacokinetics investigation in healthy volunteers and in patients

5) Chemotherapy  Treatment of systemic infection/malignancy with specific drugs that have toxicity for infecting organism with no/minimal effects on host cells 6) Pharmacy  Preparation, compounding and dispensing the drugs  Collection, identification, purification, isolation, synthesis, standardization and quality control of medicinal substances  Large scale manufacture of drugs is Pharmaceutics

7) Toxicology  Study of poisonous effects of drugs and other chemicals (household environmental pollutants, industrial, agricultural, homicidal) with emphasis on detection, prevention and treatment of poisoning  Study of adverse effects of drugs

8) Pharmaceutical chemistry  Deals with chemical structure and chemical reactions of active principles of drugs 9) Pharmacognosy (Materia Medica)  Deals with source, identification, physical and chemical characteristic of drugs obtained from plants 10) Posology  Deals with doses

DRUG  Derived from French word, drogue (dry herb)  Chemical substance used in minute quantities for the diagnosis, prevention or treatment of diseases  All biologically active chemicals including poisons and addictive substances are drugs

MEDICINE  Chemical prep. usually but not necessarily contains one or more drugs administered with the intention of therapy  Active drug+other sub. For its convenient use  Drugs are given as such rather than released by physiological mechanism

DRUG NOMENCLATURE Drug has 3 names 1) Chemical Name  According to molecular structure of drug  Long, complicated, inconvenient and not used clinically e.g. acetylsalicylic acid of aspirin

2) GENERIC NAME (NON PROPRIETARY)  Official name or approved name  Simple, accepted world wide and used in text books, pharmacopoeias, medical journals and other reference books E.g. ampicillin, aspirin

3) Proprietary Name Brand name chosen by pharmaceutical firm Same drug may have different names e.g. paracetamol (Acenol, Aminol, Atamol etc)