pentobarbital will reduce the level or influence of larotrectinib by impacting hepatic/intestinal enzyme CYP3A4 metabolism.pentobarbital will reduce the level or impact of tramadol by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Use Warning/Check. Reduced AUC of tramadol along with the Lively metabolite (O-desmethyltramadol) when coadmi