Which antifungal agent inhibits the enzyme squalene epoxidase?
- A Itraconazole
- B Terbinafine ✓
- C Caspofungin
- D Flucytosine
Correct answer: B. Terbinafine
Explanation
Terbinafine blocks squalene epoxidase, preventing conversion of squalene to lanosterol in ergosterol synthesis. This step lies upstream of the lanosterol 14-alpha-demethylase step targeted by azoles, so itraconazole acts at a different point. The resulting squalene accumulation is toxic to fungi, making terbinafine fungicidal against dermatophytes.
Reference: Katzung's Basic and Clinical Pharmacology, 16th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.