Posology

The word “posology” is derived from the Greek words “posos”, meaning ‘how much’ and “logos”, meaning ‘science’.
It means it is the branch of medical science which deals with doses or quantity of drugs which can be administered to produce the required pharmacological actions.

Factors affecting dose and action of drugs

1. Age
2. Bodyweight
3. Sex
4. Route of administration
5. Time of administration
6. Presence of disease
7. Environmental factors
8. Emotional factors
9. Accumulation
10. Synergism (Addition, Potentiation)
11. Antagonism
12. Habituation and Addiction
13. Idiosyncrasy
14. Hypersensitivity
15. Tolerance
16. Tachyphylaxis