- Caution should be exercised when administering paclitaxel (Taxol) concomitantly with medicines known to inhibit (e.g. ketoconazole and other imidazole antifungals, erythromycin, fluoxetine, gemfibrozil, cimetidine, ritonavir, saquinavir, indinavir and nelfinavir) OR induce (e.g. rifampicin, carbamazepine, phenytoin, efavirenz and nevirapine) either CYP2C8 or CYP3A4.