Moderate
Amlodipine × Fluconazole
Calcium channel blockers (dihydropyridines)×Antifungals, triazole derivatives
Mechanism
Fluconazole at high doses (200 mg/day or above) blocks CYP3A4 – the main amlodipine metabolic route. Amlodipine plasma levels may rise. The effect is clinically weak in short courses.
Symptoms
Lower blood pressure, postural dizziness, fatigue. Older patients: fall risk.
Management
For short fluconazole courses (up to 7 days), no adjustment is usually needed. For prolonged systemic therapy (>14 days), reduce amlodipine by 25% with blood pressure monitoring.