pentobarbital will lessen the level or result of nisoldipine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Warning/Observe.pentobarbital will decrease the extent or impact of elbasvir/grazoprevir by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Contraindicated. The therapeutic result of elbasvir/grazoprevir could be minimiz