pentobarbital will reduce the extent or impact of fosamprenavir by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Watch.pentobarbital will lessen the extent or impact of abemaciclib by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of abemaciclib with solid CYP3A4 inducer