Effect of Antiepileptic Drugs on Oral Contraceptives

Metabolism of the OCP and the POP is accelerated by:

• Carbamazepine
• Phenytoin
• Phenobarbitone
• Oxcarbazepine
• Topiramate. 

The higher oestrogen (50mcg) containing OCP preparations are more effective than the typical lower dose preparations (30mcg) in patients on enzyme inducing medication, but are still approximately 10 times less effective than in women on the 30mcg preparations who do not take anti-epileptic medication.

There is no evidence that the metabolism of Depo-provera is affected by anti-epileptic medication.