Levetiracetam: a long-term follow-up study of efficacy and safety

To evaluate the efficacy and safety of long-term add-on treatment with levetiracetam 1,000-4,000 mg/day.

In this multicenter, open-label follow-up study, 505 patients, from 10 European countries, who had benefited from previous add-on treatment with levetiracetam in a clinical trial or compassionate-use program were enrolled; 274 (54.3%) stayed to the end. Most then continued levetiracetam by prescription or in a named patient program, where it was not yet commercially available. Mean treatment duration was 1,045 days (range: 24 days to >7 years). Median daily dosage was 3,000 mg/day (range: 250-6,000 mg/day), with 250 (49.5%) patients receiving levetiracetam for >3 years.

Median total and partial seizure frequency per week over the evaluation period were 0.8 and 0.7; seizure frequency per week was generally stable over time and remained low. There was a probability of 6.6% of remaining seizure-free for the first 3 years, and of 18.9% of having a seizure-free period of at least 3 years at any time. Most adverse events were mild or moderate and unrelated to study drug. Levetiracetam was well tolerated, and provided stable seizure control during long-term treatment.