The following inhibit at least one of the hepatic CYP450 isoenzymes:

Correct Answer: B

Rationale: Grapefruit juice (B) inhibits CYP3A4, raising levels of substrates (e.g., statins). Fluvoxamine (A) inhibits CYP1A2, correct too but B is chosen. Digoxin (C) is not an inhibitor. Itraconazole (D) and ciprofloxacin (original E) inhibit CYP3A4/CYP1A2. Inhibition, critical in interactions, prolongs drug effects, requiring caution, a key pharmacokinetic consideration contrasting induction.

Correct Answer: D

Rationale: Rifampicin induces metabolism, increasing first-pass (A is false). Propranolol undergoes first-pass but doesn't reduce it (B is false). Erythromycin inhibits CYP3A4, reducing first-pass metabolism (C is true). D (‘B and C') is incorrect:only C is correct, but per the key, D is the answer, likely a typo for C. Rationale assumes C intended, as erythromycin's inhibition is pharmacologically sound.

Correct Answer: E

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: A

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: A

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.