The principal cytochrome P450 isoenzyme involved appears to be CYP2E1, with CYP1A2 and CYP3A4 as further pathways. Approximately eighty five% of the oral dose appears while in the urine in 24 several hours of administration, most as the glucuronide conjugate, with little amounts of other conjugates and unchanged drug (see OVERDOSAGE) for toxicity f