FELBAMATE LEVELS IN PATIENTS WITH EPILEPSY

The usefulness of felbamate (FBM) levels in managing epilepsy patients has not been determined. The purpose of the present study was to dete rmine if FBM levels obtained at routine office visits correlated with side effects reported by patients. We determined FBM levels by high-pr essure liquid chromatography (HPLC) of 46 epilepsy patient plasma spec imens (41 patients) and assessed medication toxicity and seizure frequ ency by a questionnaire. Thirty-six patients were treated with other a ntiepileptic drugs (AEDs); concomitant AED levels not in ranges believ ed to cause toxicity. FBM levels ranged from 9 to 134 mu g/ml, and wer e divided into three groups for analysis, resulting in low-range (9-36 mu g/ml), mid-range (37-54 mu g/ml), and high-level (44-134 mu g/ml) groups. Anorexia and complaints of severe side effects were reported s ignificantly more often in the high-level group as compared with the l ow- and midrange groups. Significantly more patients in the high-level group (10/13) reported decreased seizure frequency, as compared with 12 of 30 of patients in the low- and midrange groups combined. FBM lev els correlated linearly with doses overall, but most closely in FBM mo notherapy patients.