Objectives: To assess the treatment efficacy and tolerability of pregabalin in patients with idiopathic restless legs syndrome (RLS) in South Korea.~Study Design: A randomized, double-blind, placebo-controlled, multicenter clinical trial Study period: total 14 weeks: 2 weeks for placebo run in period and 12 weeks treatment after randomization (titration for 4 weeks and maintenance for 8 weeks).~Subjects: a total number of 100 participants (randomly assigned 1:1 to pregabalin or placebo). The sample number was calculated based on a superiority design, 1-sided, alpha 0.05 with power 80% and drop rate 10%.~Inclusion criteria: adults aged between 19-80 and diagnosed with idiopathic RLS with IRLS score of 15 or more.~Exclusion criteria: Secondary RLS; serum ferritin < 10 μg/L or history of oral iron therapy within 3 months or intravenous iron therapy within 1 year; severe comorbid medical or psychiatric disorders; history of pregabalin or gabapentin treatment within 3 months; other comorbid sleep disorders or shift workers.~Treatment schedule and dose~- Placebo responders, who showed a decrease of IRLS score of 40% or more, are excluded before randomization. Subjects will randomly assigned to receive either pregabalin or placebo with a 1:1 allocation. A starting dose is 75 mg/day for 2 weeks (taken 1-2 hours before habitual bedtime). At the visit of 2 weeks and 4 weeks, a dose can be titrated by 75-150 mg according to the response and tolerability. A dose ranging 75-300 mg per day will be maintained for 8 weeks.~Primary outcome: changes in IRLS score after 12-week treatment. Secondary outcomes: remission rate (decrease in IRLS score of 50% or more), CGI (clinical global impression)-improvement, changes in 10-cm visual analog scale (VAS), RLS-6, PSQI (pittsburgh sleep quality index), ISI (insomnia severity index), Johns Hopkins RLS QoL after 12-week treatment.~Statistical analysis: ANCOVA for changes in IRLS score with a baseline IRLS score as a covariate.~Tolerability: Safety profiles and Liverpool Adverse Event Profile (LAEP) will be assessed.
This randomized, double-blind, placebo-controlled, multicenter clinical trial is designed to to assess the treatment efficacy and tolerability of pregabalin in patients with idiopathic restless legs syndrome in South Korea.