INTRODUCTION

Temsirolimus, sirolimus and everolimus are inhibitors of the mammalian target rapamycin (mTOR), an enzyme that regulates cell growth and proliferation. Temsirolimus is a prodrug of sirolimus. Although mTOR inhibitors are known to be extensively metabolized by cytochrome P450 3A4 (CYP3A4), no drug monitoring is systematically recommended when these molecules are administered for cancer therapy in contrast to what is recommended for organ transplantations[1]. We report on a probable interaction between mTor inhibitors and carbamazepine (an enzyme-inducing antiepileptic drug), in which carbamazipine leads to an ineffectiveness of everolimus and temsirolimus therapy which is resolved by a dose adjustment after drug monitoring.