pentobarbital will lower the extent or influence of ritonavir by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Warning/Check.pentobarbital will lessen the level or effect of midazolam by influencing hepatic/intestinal enzyme CYP3A4 metabolism. Use Warning/Keep track of.I provide the anti-emetic Metoclopramide 10mg and it is cost-free.