butabarbital will lower the level or effect of nicardipine by impacting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Watch.butabarbital will lessen the level or influence of vardenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.buprenorphine, long-acting injection and butabarbital both of those increas