Pharmacology

Question 1

First order kinetics

Answer 1

Most drugs
Excrete certain percentage of drug per unit of time

Rate of drug elimination is directly proportional to the serum drug concentration
Half life is independent of drug dosage
The fraction of drug eliminated is constant


Question 2

Zero order kinetics

Answer 2

Excrete a constant amount of drug per unit time regardless of serum drug concentration

Half-life is dependent upon drug dosage
The fraction of drug eliminated is not constant
Examples: aspirin, alcohol, diazepam, chloramphenicol

Question 3

Phase 1 metabolism

Answer 3

Reduction
Oxidation
Hydrolysis
(ROH)

Cytochrome P450 enzymes, occurs in liver

Question 4

Phase 1 substrates

Answer 4

Caffeine
Warfarin
Phenytoin
Omeprazole
Propanolol
Midazolam
Erythromycin

Question 5

Phase 1 inhibitors

Answer 5

Fluconazole
Some erythromycin
Cimetidine/Ranitidine
Amiodarone

Question 6

Phase 1 (CP450) inducers

Answer 6

Rifampin
Dexamethasone
Barbiturates

Question 7

Phase 2 metabolism

Answer 7

Glucuronidation
Acetylation
Sulfation
(GAS)

Acetylation and glucuronidation not fully developed at term
Many different enzymes

Question 8

Drug metabolism in neonates

Answer 8

Rate of metabolism low - need longer dosing intervals