Major
Dabigatran × Ketoconazole
Direct thrombin inhibitor×Systemic antimycotics. Imidazole derivatives
Mechanism
Ketoconazole strongly blocks P-glycoprotein, the main transporter of dabigatran. Dabigatran plasma levels double, especially in renal impairment.
Symptoms
Gum bleeding, epistaxis, bruising without trauma, blood in urine or stool, menorrhagia. Severe cases include gastrointestinal or intracranial haemorrhage. Risk rises in patients over 65 and with prior peptic ulcer disease.
Management
The combination is not prescribed. Alternative antifungals: terbinafine (no P-glycoprotein use) for dermatophytosis, or echinocandins for systemic mycoses.