pentobarbital will lower the level or outcome of fosamprenavir by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.pentobarbital will decrease the extent or effect of lonafarnib by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. Lonafarnib is usually a delicate CYP3A4 substrate. Coadministration wit