Drug-drug interactions among drugs prescribed for nontuberculous mycobacterial infection and epilepsy: A case report.

WHAT IS KNOWN AND OBJECTIVE: Multi-drug combinations often make chemotherapy difficult owing to drug-drug interactions (DDIs). We report a rare and difficult-to-treat case due to DDIs between drugs for Mycobacterium avium complex (MAC) infection and antiepileptic drugs. CASE DESCRIPTION: A 70-year-old Japanese woman was diagnosed as having pulmonary MAC disease. She had a history of symptomatic epilepsy, which was successfully treated with phenytoin and phenobarbital. Serum phenytoin concentrations increased upon the initiation of MAC infection treatment. WHAT IS NEW AND CONCLUSION: We evaluated DDIs and adjusted the dosage of drugs by monitoring the serum drug level.