pentobarbital decreases levels of toremifene by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Check. CYP3A4 inducers improve price of toremifene metabolism, lowering the continuous-point out focus in serum.pentobarbital will lessen the extent or effect of sildenafil by influencing hepatic/intestinal enzyme CYP3A4 metabolism. St