pentobarbital will reduce the level or effect of methadone by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Observe.pentobarbital will minimize the extent or impact of buprenorphine subdermal implant by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Keep an eye on Closely. Watch clients now on buprenorp