A 35-year-old woman with poorly controlled diabetes mellitus presents with vaginal candidiasis confirmed by KOH mount. She has no prior antifungal exposure and normal renal function. What is the drug of choice for treatment?

Explanation

## Drug of Choice for Vaginal Candidiasis **Key Point:** Fluconazole is the first-line agent for uncomplicated vulvovaginal candidiasis in non-pregnant women with normal renal function. ### Rationale for Fluconazole 1. **Mechanism**: Azole antifungal; inhibits fungal lanosterol 14α-demethylase (CYP51), disrupting ergosterol synthesis. 2. **Bioavailability**: Excellent oral absorption; achieves high vaginal concentrations. 3. **Dosing**: Single 150 mg oral dose is highly effective for uncomplicated VVC; alternative is 100 mg daily × 3 days. 4. **Safety**: Well-tolerated, minimal drug interactions at standard doses, safe in renal impairment (no dose adjustment needed). ### Comparison with Alternatives | Drug | Class | Use in VVC | Limitation | |------|-------|-----------|------------| | **Fluconazole** | Azole | First-line, oral | None (preferred) | | Amphotericin B | Polyene | Severe/invasive only | Nephrotoxic, IV only, overkill for VVC | | Terbinafine | Allylamine | Dermatophytes, nails | Not effective for Candida; used for tinea | | Griseofulvin | Antifungal | Dermatophytes only | No activity vs. Candida; obsolete for vaginal use | **Clinical Pearl:** A single 150 mg dose of fluconazole achieves cure rates >90% in uncomplicated VVC. Recurrent VVC (≥4 episodes/year) requires long-term suppressive therapy (fluconazole 150 mg weekly × 6 months). **High-Yield:** Fluconazole is also first-line for oropharyngeal candidiasis in non-immunocompromised hosts and for cryptococcal meningitis prophylaxis in HIV patients.