8. How to calculate
1. Based on Age-
• Young's Rule:
• Dilling’s Rule:
• Fried’s Rule:
9. 2. Based on Weight-
• Clark’s rule:
3. Based of Body Surface Area:
3. Based on body Surface Area-
• Catzel Rule:
10.
11. • Polycyclic aromatic hydrocarbons (PAHs) of
tobacco smoke have been associated with the
induction of CYP enzymes such as CYP1A1,
CYP1A2 and possibly CYP2E1 and UGT (uridine
diphosphate-glucuronosyltransferases) enzymes.
The drugs metabolized by CYP1A1, CYP1A2,
CYP2E1 and UGT enzymes might be affected by
tobacco smoking and the smokers taking
medications metabolized by those enzymes, may
need higher doses due to decreased plasma
concentrations through enhanced induction by
PAHs of tobacco smoke.