PHOTOSENSITIVE EPILEPSY - A MODEL TO STUDY THE EFFECTS OF ANTIEPILEPTIC DRUGS - EVALUATION OF THE PIRACETAM ANALOG, LEVETIRACETAM

The experimental antiepileptic drug, levetiracetam (UCB L059), a pirac etam analogue has been investigated in photosensitive patients in the ''photosensitivity model'', an early phase II study. A total of 12 pat ients (10 females, 2 males) with a mean age of 21.5 years (range 13-38 ) were investigated during a 3 day period in 3 centres (France, The Ne therlands, Germany), using the same standardised method. The subjects were either treated with a single oral dose of 250 mg, 500 mg, 750 mg or 1000 mg. In addition, 4 patients took 250 mg b.i.d. for 3-5 days, a fter which they were re-examined. In 9 of 12 photosensitive patients ( 75%) a clear suppression (3 patients) or abolishment (6 patients) of I FS evoked photoparoxysmal EEG responses was found. This effect appeare d to be dose-dependent, the higher the dose the greater the effect; co mplete abolishment was only seen at dosages of 750 mg and 1000 mg, occ urring at peak plasma levels and lasting between 6 and 30 h. There was no indication of pharmacokinetic interaction with concomitant antiepi leptic drugs such as valproic acid, ethosuximide or phenobarbitone. No serious side-effects were seen and some patients reported enhancement of their mood. Two patients with myoclonic jerks noticed a clear redu ction of their myoclonus, although this was not one of the objectives of the study. In conclusion, levetiracetam showed a clear antiepilepti c effect in the photosensitivity model.