Rapid versus slow withdrawal of antiepileptic monotherapy in two-year seizure-free adults patients with epilepsy (RASLOW) study: A pragmatic multicentre, prospective, randomized, controlled study

Purpose To establish whether a slow or a rapid withdrawal of antiepileptic monotherapy influences relapse rate in seizure-free adults with epilepsy and calculates compliance and differences in the severity of relapses, based on the occurrence of status epilepticus, seizure-related injuries, and death. Methods This is a multicentre, prospective, randomized, open label, non-inferiority trial in people aged 16 + years who were seizure-free for more than 2 years. Patients were randomized to slow withdrawal (160 days) or rapid withdrawal (60 days) and were followed for 12 months. The primary outcome was the probability of a first seizure relapse within the 12-months follow-up. The secondary outcomes included the cumulative probability of relapse at 3, 6, 9, and 12 months. A non-inferiority analysis was performed with non-inferiority margin of - 0.15 for the difference between the probabilities of seizure recurrence in slow versus rapid withdrawal. Results The sample comprised 48 patients, 25 randomized to slow withdrawal and 23 to rapid withdrawal. Median follow-up was 11.9 months. In the intention-to-treat population, 3 patients in the slow-withdrawal group and 1 in the rapid withdrawal group experienced seizure relapses. The corresponding probabilities of seizure recurrence were 0.12 for slow withdrawal and 0.04 for rapid withdrawal, giving a difference of 0.08 (95% CI - 0.12; 0.27), which is entirely above the non-inferiority margin. No patients developed status epilepticus and seizure-related injuries or died. Risks were similar in the Per-Protocol population. Conclusions Seizure-relapse rate after drug discontinuation is lower than in other reports, without complications and unrelated to the duration of tapering.