Questions And Correct Answers (Verified
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1. Which phase of drug metabolism is primarily responsible for
oxidation reactions?
A. Phase I
B. Phase II
C. Phase III
D. Phase IV
Answer: A. Phase I
Rationale: Phase I reactions involve functionalization processes such
as oxidation, reduction, and hydrolysis, primarily mediated by
cytochrome P450 enzymes in the liver.
2. Which route of administration provides the fastest onset of action?
,A. Oral
B. Intramuscular
C. Intravenous
D. Subcutaneous
Answer: C. Intravenous
Rationale: IV administration delivers drugs directly into systemic
circulation, bypassing absorption barriers.
3. What is the primary purpose of a drug’s therapeutic index?
A. Measure drug cost-effectiveness
B. Compare efficacy between drugs
C. Compare toxic dose to effective dose
D. Determine absorption rate
Answer: C. Compare toxic dose to effective dose
Rationale: Therapeutic index is the ratio between toxic dose (TD50)
and effective dose (ED50).
4. Which organ is the primary site of drug metabolism?
A. Kidney
B. Liver
,C. Lung
D. Pancreas
Answer: B. Liver
Rationale: The liver contains most drug-metabolizing enzymes,
especially cytochrome P450 systems.
5. A drug with high protein binding will most likely have:
A. Faster elimination
B. Lower half-life
C. Longer duration of action
D. No pharmacologic activity
Answer: C. Longer duration of action
Rationale: Highly protein-bound drugs remain in circulation longer
and are released slowly.
6. Which class of drug blocks beta-adrenergic receptors?
A. ACE inhibitors
B. Beta blockers
C. Calcium channel blockers
D. Diuretics
, Answer: B. Beta blockers
Rationale: Beta blockers inhibit sympathetic nervous system effects by
blocking beta receptors.
7. What is the main function of CYP450 enzymes?
A. Drug excretion
B. Drug absorption
C. Drug metabolism
D. Drug distribution
Answer: C. Drug metabolism
Rationale: CYP450 enzymes are responsible for oxidative metabolism
of many drugs.
8. Which electrolyte imbalance is commonly associated with loop
diuretics?
A. Hyperkalemia
B. Hypokalemia
C. Hypernatremia
D. Hypercalcemia