Pharmacology · single question
A patient with a known fungal infection has a cell wall containing chitin, beta-glucans, and mannans. The MOST appropriate antifungal is:
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Correct answer: C. Clotrimazole (inhibits ergosterol synthesis — azole antifungal)
- A. Metronidazole targets anaerobic bacteria and protozoa by disrupting DNA — it has no antifungal activity.
- B. Mebendazole is an antiparasitic (antihelminthic) used for intestinal worm infections — not a fungal infection.
- C. Correct. Chitin, beta-glucans, and mannans in the cell wall identify this as a FUNGAL infection. Clotrimazole (an azole antifungal) inhibits the fungal cytochrome P450 enzyme lanosterol 14α-demethylase, blocking ergosterol synthesis. Without ergosterol (the fungal equivalent of cholesterol), the fungal cell membrane becomes disrupted and the organism dies.
- D. Pyrazinamide is an anti-tuberculosis drug targeting Mycobacterium tuberculosis — completely unrelated to fungal infections.