Low-dose pramipexole in the management of restless legs syndrome. An open label trial

Dopaminergic agents are considered the treatment of choice for restless legs syndrome (RLS); levodopa is the only substance licensed for this disorder in some European countries. However, in a substantial proportion of patients symptoms are not adequately controlled for a whole night due to the short half-life of levodopa or because symptom augmentation may develop. To further investigate the impact of pramipexole on the management of RLS we performed a short-term open label trial with pramipexole in 17 patients who were being insufficiently treated with levodopa or for whom pramipexole was primarily being considered because of the severity of the RLS symptoms. A single dose of 0.125-0.75 mg pramipexole (mean 0.3 +/- 0.2 mg) in the evening resulted in a significant improvement of subjective RLS symptoms as rated by the International RLS Study Group Severity Scale (IRLS scores: 29.8 +/- 4.7 baseline vs. 7.3 +/- 5.9 endpoint; p = 0.0001). Polysomnographic recordings showed a significant improvement of the periodic leg movements (PLM) index, PLM sleep arousal index, sleep-onset latency, total sleep time and sleep efficiency. All patients who had developed a worsening of RLS symptoms under levodopa recovered from daytime symptoms after their medication was switched to pramipexole. Since pramipexole was well tolerated, an ideal dosage to control RLS symptoms could be reached rapidly. Pramipexole has proven a suitable alternative in patients with moderate to severe RLS, particularly when their therapy has to be switched to a dopamine agonist.