Effect of ropinirole on sleep onset: a randomized, placebo-controlled study in healthy volunteers.

Somnolence and "sleep attacks" have been reported as an adverse effect of several antiparkinsonian drugs. The authors document, in a placebo-controlled, randomized, double-blind, crossover study performed in 20 healthy volunteers, using the Multiple System Latency Test (MSLT) as primary outcome, that ropinirole reduces time to sleep onset in humans. Ropinirole therapy was not associated with daytime episodes of rapid eyes movement (REM) sleep.