Restless legs syndrome improved by pramipexole: a double-blind randomized trial.

BACKGROUND: Restless legs syndrome (RLS) is characterized by leg paresthesia associated with an irresistible urge to move. Currently used dopaminergic agents, such as levodopa, pergolide, and bromocriptine, offer incomplete control of sensory and motor symptoms and induce severe side effects.

OBJECTIVE: To assess the safety and efficacy of pramipexole, a full D3-receptor agonist, in the treatment of RLS.

METHODS: Ten RLS patients were studied before and after two 1-month treatments (placebo and pramipexole) administered in a double-blind crossover fashion. The severity of sensory and motor manifestations was assessed by 1 week of home questionnaires and 2 consecutive nights of sleep laboratory recordings. The indexes of periodic leg movement during sleep (PLMS) and during wakefulness (PLMW) were used as primary outcome variables.

RESULTS: Pramipexole dramatically reduced the PLMS index to normal values (Wilcoxon, p = 0.005). The PLMW index was also significantly reduced (Wilcoxon, p = 0.007). Pramipexole also alleviated leg discomfort at bedtime and during the night as measured by the home questionnaires.

CONCLUSIONS: Pramipexole is the most potent therapeutic agent ever tested for RLS. Measures of both sensory and motor functions returned to normal values after treatment. Moreover, these results further support the hypothesis that D3 receptors play a major role in the physiopathology of this condition.