butabarbital will lessen the level or result of nicardipine by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Keep an eye on.butabarbital will lessen the level or effect of midazolam by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Observe.For those who have been using this medicine for a very long time,