a) Certain anticonvulsants,(phenytoin, carbamazepine, barbiturates, primidone, topiramate, oxcarbazepine)
3
Clarification: Although the interaction of certain anticonvulsants with POPs is not harmful to women, it is likely to reduce the effectiveness of POPs. Whether increasing the hormone dose of POPs alleviates this concern remains unclear. Use of other contraceptives should be encouraged for women who are long-term users of any of these drugs.