All of the following drugs demonstrate a fungicidal effect, EXCEPT:

Correct Answer: D

Rationale: Terbinafine, amphotericin B, and ketoconazole are fungicidal, killing fungi. Miconazole is typically fungistatic, inhibiting growth rather than killing, though it can be fungicidal at high doses.

Correct Answer: B

Rationale: Rimantadine inhibits the M2 ion channel of influenza A, preventing uncoating of viral RNA, thus blocking viral replication.

Correct Answer: B

Rationale: Rimantadine prevents influenza A by inhibiting the M2 ion channel, blocking viral uncoating, making it effective for prophylaxis.

Correct Answer: C

Rationale: Histamine H1 receptor stimulation causes bronchoconstriction (not dilatation), vasodilation of small vessels, and sensory nerve irritation. H2 receptors mediate gastric secretion.

Correct Answer: D

Rationale: Fexofenadine is an active metabolite of terfenadine, a second-generation antihistamine, designed to reduce cardiac side effects like arrhythmias.