The principal cytochrome P450 isoenzyme involved appears to be CYP2E1, with CYP1A2 and CYP3A4 as more pathways. Close to 85% of the oral dose appears during the urine inside 24 hrs of administration, most as being the glucuronide conjugate, with modest amounts of other conjugates and unchanged drug [see OVERDOSAGE] for toxicity data.Serious pain sy