Increased clearance of sex hormones w/ phenytoin, barbiturates, primidone, carbamazepine, rifampicin, & possibly oxcarbazepine, topiramate, felbamate, griseofulvin & products containing St. John's wort. Possible variable effects on the clearance of sex hormones w/ HIV/HCV PI & NNRTIs. Decreased clearance of sex hormones & increased plasma conc w/ strong & moderate CYP3A4 inhibitors [eg, azole antifungals (eg, itraconazole, voriconazole, fluconazole), verapamil, macrolides (eg, clarithromycin, erythromycin), diltiazem & grapefruit juice]. May influence certain lab test results including biochemical parameters of liver, thyroid, adrenal & renal function, plasma levels of carrier proteins (eg, lipid/lipoprotein fractions, carbohydrate metabolism, coagulation & fibrinolysis parameters).