Phenytoin-induced methadone withdrawal.
Methadone-maintained volunteers experienced moderately severe opiate withdrawal symptoms within 3 or 4 days of beginning phenytoin in therapeutic doses. The area under the methadone plasma concentration-time curve decreased while the ratio of the pyrrolidine-to-metabolite excretion in urine to this area increased significantly. This suggests that phenytoin accelerates methadone metabolism. Methadone dosing adjustments should be anticipated when phenytoin is initiated or discontinued in methadone-maintained patients.
D000328:Adult; D004334:Drug Administration Schedule; D004347:Drug Interactions; D006801:Humans; D008297:Male; D008691:Methadone / Q000008:administration & dosage / Q000009:adverse effects*; D010672:Phenytoin / Q000009:adverse effects*; D011759:Pyrrolidines / Q000652:urine; D013375:Substance Withdrawal Syndrome / Q000139:chemically induced* / Q000378:metabolism
D011759:Pyrrolidines; D010672:Phenytoin; D008691:Methadone