Since paclitaxel is metabolised by cytochrome P450 isoenzymes CYP 3A4 and 2C8, caution should be exercised with other drugs known to inhibit (e. g. erythromycin, fluoxetine, gemfibrozil, imidazole antifungals) or induce (e. g. rifampicin, carbamazepine, phenytoin, phenobarbital, efavirenz, nevirapine) these enzymes as they may affect the pharmacokinetics of paclitaxel.