Moderate
Amitriptyline × Ketoconazole
Tricyclic antidepressants (TCA)×Systemic antimycotics. Imidazole derivatives
Mechanism
Ketoconazole blocks CYP3A4 (one of the amitriptyline metabolic routes). TCA plasma levels may rise.
Symptoms
Worsening anticholinergic symptoms, drowsiness, tachycardia. Older patients: delirium and fall risk.
Management
For short ketoconazole courses, reduce amitriptyline by 25% temporarily. Alternative antifungals without CYP3A4 effect: terbinafine for dermatophytosis or echinocandins for systemic mycoses.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.