Improvement in verbal memory after withdrawal of carbamazepine and valproate in patients with well-controlled epilepsy: a randomized, double-blind study.

BACKGROUND

For most major antiepileptic drugs, neuropsychological side effects have been reported. Healthy volunteer studies have found that both carbamazepine and valproate impair aspects of verbal memory.

OBJECTIVE

The aim of this study was to assess the effects of carbamazepine and valproate on verbal memory, in a well-controlled epilepsy population.

METHODS

This was carried out with a randomized, double-blind and placebo-controlled study of anticonvulsant withdrawal in patients receiving monotherapy.

RESULTS

In the carbamazepine group (n=92), withdrawal significantly improved recall after 30 min (P=0.03). In the valproate group (n=32), withdrawal significantly improved performance of immediate word span (P=0.04).

CONCLUSIONS

Withdrawal was randomized to placebo, but the choice of medication was not randomized to placebo. This means that the shown differences in neuropsychological outcome cannot with full certainty be attributed to either antiepileptic drug. The improvement of memory, after both carbamazepine and valproate withdrawal, was slight, and the impact on daily life function is uncertain.