rct for pregabalin in restless legs syndrome in south korea

Conditions: Restless Legs Syndrome

Summary: 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.

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.

Eligibility criteria:
inclusion criteria: * irls (international restless legs scale) score ≥ 15 * rls symptom occurring ≥ 3 times/week and persisting over ≥ 6 months * drug-naive patients or those who stop taking rls drugs for ≥ 1 week before screening exclusion criteria: * secondary rls (including iron deficiency anemia, pregnancy, chronic kidney disease \[egfr \< 60 ml/min/1.73 m2\], peripheral neuropathy, others) * 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 * high risk of obstructive sleep apnea by stop-bang questionnaire * other comorbid sleep disorders or shift workers * hypersensitivity to pregabalin * galactose intolerance, lapp lactase deficiency, or glucose-galactose malabsorption

Keywords: restless legs syndrome; pregabalin; willis-ekbom disease