1. The main branches of pharmacology
The interactions of chemicals are divided into two categories:-
Pharmacodynamics
Pharmacokinetics

2. the effects of the drug on the body
PHARMACODYNAMICS
the effects of the drug on the body
how the effects of a drug are generated

3. Pharmacokinetics
The way the body affects the drug with time considering absorption, distribution, metabolism, excretion.

4. DRUG ABSORPTION, DISTRIBUTION, EXCRETION
Absorption Most drugs are given orally passing through the gut wall to enter the bloodstream

5. Stability to acid and enzymes
Absorption…
Depends on:-
Formulation
Stability to acid and enzymes
Food in stomach
Lipid solubility

6. Routes of administration
enterally ( via gastrointestinal route) or parenterally ( non-gastrointestinal route)
ORAL….
Convenient but
Some drugs are destroyed by acid or enzymes in gut

7. Parenterally:- Intravenous injection… Drugs enter circulation and bypass the absorption barriers Intramuscular/ subcutaneous injection Other routes:Topical - substance is applied directly where needed -Inhalation (asthma inhalers) (lotions, ointments)transdermal Enterally: Sublingual , oral rectal

8. When drug reaches the circulation and penetrates tissues
DISTRIBUTION
When drug reaches the circulation and penetrates tissues

9. Most drugs are eliminated
EXCRETION
Renal
Most drugs are eliminated
via kidneys
Biliary
Some drugs concentrated in bile excreted into intestine may be reabsorbed