pentobarbital will lessen the level or effect of verapamil by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Check.pentobarbital will reduce the extent or impact of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Stay away from or Use Alternate Drug. Potent CYP3A4 inducers are expected to induce sizeable dec