pentobarbital will lower the extent or result of fesoterodine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Check.pentobarbital decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Observe. CYP3A4 inducers raise price of toremifene metabolism, reducing the regular-condition con