Increased clearance of sex hormones w/ phenytoin, barbiturates, primidone, carbamazepine, rifampicin, oxcarbazepine, topiramate, felbamate, griseofulvin, nevirapine & St. John's wort containing-products. Increase plasma levels w/ azole antifungals, cimetidine, verapamil, macrolides, diltiazem, PIs, antidepressants.