Efficacy and safety of pramipexole in Japanese patients with primary restless legs syndrome: A polysomnographic randomized, double-blind, placebo-controlled study.
OBJECTIVE
To evaluate the efficacy of pramipexole on polysomnographic measures, patient ratings and a clinical rating in Japanese patients with primary restless legs syndrome (RLS).


METHODS
Patients with moderate to severe RLS having periodic limb movements in bed index (PLMI)>or=5 were randomly assigned to receive pramipexole or placebo in a 6-week, double-blind, placebo-controlled study with forced titration from 0.125 to 0.75mg/day. Both polysomnography (PSG) and the suggested immobilization test (SIT) were performed at baseline and 6weeks after starting treatment.


RESULTS
The analysis of covariance of log-transformed PLMI showed that the adjusted means at the end of study were significantly smaller in the pramipexole group than in the placebo group (p=0.0019). In all patients, variables on SIT did not show any differences between the two groups, whereas a significant improvement was shown in the pramipexole group compared with the placebo group for patients with a SIT-PLM index at baseline >or=15. Pramipexole group showed a significant reduction in the International Restless Legs Syndrome Study Group rating scale (IRLS; p=0.0005), a significant improvement in both Patient Global Impression (PGI; p<0.0001) and Clinical Global Impressions (CGI-I; p=0.0488), and a significantly greater mean reduction in the Pittsburgh Sleep Quality Index (PSQI; p=0.0016), when compared with those of placebo group at week 6.


CONCLUSIONS
Pramipexole is highly efficacious in the reduction of PLMI and in the improvement of subjective severity of RLS and subjective sleep disturbance caused by the disorder.
Inoue
Yuichi
Y
Japan Somnology Center, Neuropsychiatric Research Institute, Tokyo, Japan. inoue@somnology.com
Hirata
Koichi
K
Kuroda
Kenji
K
Fujita
Masahiko
M
Shimizu
Tetsuo
T
Emura
Narutsugu
N
Uchimura
Naohisa
N
Kagimura
Tatsuo
T
Sha
Koji
K
Nozawa
Taneyoshi
T
D000328:Adult; D000368:Aged; D001143:Arousal / Q000187:drug effects; D052160:Benzothiazoles / Q000009:adverse effects / Q000627:therapeutic use*; D018491:Dopamine Agonists / Q000009:adverse effects / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography / Q000187:drug effects*; D000077487:Pramipexole; D012148:Restless Legs Syndrome / Q000175:diagnosis / Q000188:drug therapy*; D012894:Sleep Stages / Q000187:drug effects; D016896:Treatment Outcome; D014851:Wakefulness / Q000187:drug effects
D052160:Benzothiazoles; D018491:Dopamine Agonists; D000077487:Pramipexole