Tell the doctor or pharmacist if taking or have recently taken another medicine, especially an anticonvulsant, anti-tuberculosis, or treatment for AIDS such as: carbamazepine, oxcarbazepine, phenobarbital, phenytoin, rifabutin, rifampicin, ritonavir, nelfinavir, nevirapine, efavirenz, or preparations based on plants containing St. John's wort (Hypericum perforatum), even when it is a medicine obtained without a prescription.