Oral side effects of new antiepiletic drugs. A review of the literature

Objective: The principal goal of the epilepsy therapy is to achieve seizure freedom while minimizing adverse effects of treatment. However, one of the adverse effects of the antiepileptic drugs, specially, Phenytoin and Valproate is the gingival hyperplasia. In fact, 6-79% of patients in chronic treatment with this drugs present gingival hyperplasia. Ten newer antiepileptic drugs have been developed since 1990s. The purpose of this review was to establish the oral side effects of the new antiepileptic drugs such as: Felbamate, Gabapentin, Lamotrigine, Topiramate, Tiagabine, Levetiracetam, Oxcarbazepine, and Zonisamide. Material and Methods: Studies regarding the adverse effect of the new antiepileptic drugs were identified by searching major electronic databases (through January 2010). The key terms used were: oral side effects antiepileptic drugs, gingival hyperplasia, gingival enlargement, Felbamate, Gabapentin, Vigabatrin, Lamotrigine, Topiramate, Tiagabine, Levetiracetam, Oxcarbazepine, and Zonisamide. Results: None of the studies that were included reported oral side effect in epileptic patients in treatment with Felbamate, Gabapentin, Oxcarbazepine Topiramate, Tiagabine, and Levetiracetam. However, Vigabatrin induced an increase in cell proliferation and contributed, together with concomitant periodontal disease, to the gingival enlargement. Approximately 10-12% of patients treated with Lamotrigine developed a pharmacologic rush that may evolve to toxic epidermal necrosis with desquamation and mucosal involvement. Studies in rats reported that the use of Zonisamide caused a reduction of dentin formation specially in the interproximal areas of the teeth. Discussion and Conclusions: Oral side effect such as gingival hyperplasia during the treatment of epileptic with the new antiepileptic drugs was only reported only in one study. However, the literature regarding the oral side effects of the new antiepileptic drugs is still insufficient. This can be attributed to the fact that the studies conduced since nowadays had been focus to the other side effects caused by the antiepileptic drugs. Therefore, a more accurate monitoring of the oral side effects of this drugs has to be performed by the clinicians in order to establish their security.