Oxcarbazepine in focal epilepsy and hepatic porphyria: a case report

Despite the development of new antiepileptic agents (AEDs), the therapy of epilepsies along with hepatic porphyrias remains difficult. Most AEDs such as carbamazepine (CBZ), phenytoin (PHT), valproate (VPA), and lamotrigine (LTG) may precipitate clinically latent porphyria by inducing hepatic metabolism and increasing hepatic heme synthesis. Actually, only gabapentin (GBP), an AED without any hepatic metabolism, is known as a potential therapy for partial seizures in patients having hepatic forms of porphyria.

We present the case of a 28-year-old man with porphyria cutanea tarda (PCT) who has had pharmacoresistant epilepsy with complex partial and secondarily generalized seizures since early childhood. Despite having undergone several AED therapies over the years, no seizure-free interval had been observed. Only CBZ could cause a seizure reduction, but this treatment had to be discontinued as an elevation of the transaminases as well as pruritus and erythema were noted. The patient was then started on oxcarbazepine (OCBZ), a ketoanalogue of CBZ similar in its pharmacologic mechanism as well as its clinical use, but which, in contrast to CBZ, has only a low hepatic induction of microsomal enzymes. A final maintenance dose four times higher than that of CBZ was prescribed.

In the follow-up, the patient stopped having seizures, and his liver functions became normal.

It can be concluded that OCBZ can successfully be administered to patients with hepatic porphyria and focal epilepsy who did not respond to treatment with GBP.