A quantitative study of daytime sleepiness induced by carbamazepine and add-on vigabatrin in epileptic patients.

Background: The clinical relevance of daytime sleepiness associated with carbamazepine (CBZ) and vigabatrin (VGB) was objectively assessed by the multiple sleep latency test (MSLT) and nocturnal sleep recordings.

Methods: Twenty-six patients with partial epilepsy and mean monthly seizure frequency of 4, aged 18 to 48 years, receiving chronic monotherapy with CBZ and subsequent VGB addition for 2 months (14 patients), were compared with a group of healthy subjects. Subjective daytime sleepiness was complained by 13 patients on CBZ monotherapy and 9 patients during VGB add-on treatment.

Results: No differences in nocturnal sleep parameters, but significantly shorter daytime sleep latencies at the MSLT, were detected in CBZ-treated patients as compared with healthy controls. Addition of VGB therapy did not further enhance objective daytime sleepiness.

Conclusions: Some sleepiness occurs in chronically CBZ-treated epileptic patients, which can be objectively measured by the MSLT, but it is not aggravated by add-on VGB.