PCL REVIEW 1 (pharmacology, its scopes/branches and the nature of drugs).pptx

The first section of a pharmacology review series. Describes pharmacology, its scopes/branches and the nature of drugs.

1. Pharmacology Review 1 st Session (Introduction) Albashir Tahir (MSc. Pharmacology) [email protected] [phone]/07/2023

2. Contents Pharmacology Scope/branches Nature of Drugs

3. Pharmacology The science of drugs. The study of the effects of drugs on the function of living systems. The study of substances that interact with living systems through chemical processes, especially by binding to regulatory molecules and activating or inhibiting normal body processes.

4. Pharmacology… In a broad sense, it deals with interaction of exogenously administered chemical molecules with living systems. Encompasses all aspects of knowledge about drugs. Any single chemical substance which can produce a biological response is a 'drug'. Father of pharmacology? Oswald Schmiedeberg

5. Divisions of Pharmacology Pharmacokinetics What the body does to the drug. Pharmacodynamics What the drug does to the body.

6. Drug (French: Drogue —a dry herb) It is the single active chemical entity present in a medicine that is used for diagnosis, prevention, treatment/cure of a disease. A chemical substance of known structure, other than a nutrient or an essential dietary ingredient, which, when administered to a living organism, produces a biological effect. Any chemical agent that affects living protoplasm. Any substance or product that is used or intended to be used to modify or explore the physiological system or pathological states for the benefit of the recipient.

7. Drugs in general, can thus be divided into… Pharmacodynamic agents These are designed to have pharmacodynamic effects in the recipient. Chemotherapeutic agents These are designed to inhibit/kill invading parasites/malignant cell, but have no/minimal pharmacodynamic effects in the recipient.

8. Other Aspects of Pharmacology Pharmacotherapeutics Clinical pharmacology Chemotherapy Pharmacy Toxicology

9. Nature of Drugs All drugs are chemical entities with simple or complex molecules. While majority are organic compounds, some are purely inorganic. Organic drugs may be weakly acidic (aspirin, penicillin) or weakly basic (morphine, chloroquine) or nonelectrolytes (alcohol, diethyl-ether). Most drugs are normally solids, some are liquids, and few are gaseous.

10. Nature of Drugs… The molecular weight of majority of drugs falls in the range of 100-1000 D Molecules smaller than 100 D do not generally have sufficiently specific features in terms of shape, size, configuration, chirality, distribution of charges, etc. to selectively bind to only one/few closely related target biomolecules, to the exclusion of others. Larger molecules than 1000 D do not readily pass through membranes/barriers in the body to reach the target sites in various tissues/cells. Few drugs are as small as lithium ion (7D), and some like heparin (10-20 KD), gonadotropins (>30 KD), enzymes, proteins, antibodies (>50 KD) are much bigger. Bulky molecule drugs have to be administered parenterally .

11. Nature of Drugs… Drugs are generally perceived to be chemical substances foreign to the body ( Xenobiotics ). However, many endogenous chemicals like hormones, autacoids, metabolites and nutrients are also used as drugs. Chemical congeners of these metabolites/signal molecules are an important class of drugs which act by modifying the synthesis, storage, degradation or action of these metabolites/signal molecules.