Methadone Drug-Drug Interactions Meds that increase methadone metabolism/decrease methadone effect (INCREASED RISK FOR OPIOID WITHDRAWAL): • Phenytoin, Phenobarbital, Carbamazepine, Dexamethasone, Rifampicin/rifabutin, NNRTIs (efavirenz, nevirapine), Ritonavir , Vitamin C (ascorbic acid), St John’s Wort Medications that decrease methadone metabolism/increase effect (INCREASED SEDATION/CNS DEPRESSION): • SSRI Antidepressants, Fluoroquinolones (increased sedation and prolonged Qtc time), Diltiazem, Cimetidine, Risperidone, Dextromethorphan, Chlorpromazine, Grapefruit juice, Indinavir, Azoles #Methadone #Drug #Interactions #DDIs #pharmacology #metabolism
