Dopamine agonists induce episodes of irresistible daytime sleepiness.

We assessed the prevalence and risk factors for irresistible daytime sleepiness (IDS) in a cohort of patients with Parkinson's disease (PD) treated with dopamine agonists. Seventy consecutive PD patients on dopamine agonists were interviewed. IDS was experienced by 24 patients (34.3%). Fifty percent of the pramipexole patients, 15.4% of the pergolide patients, 23.1% of the ropinirole patients and the 2 patients on bromocriptine experienced IDS. Patients who experienced IDS were younger (p = 0.009). Nineteen patients had IDS while driving, 3 sustained a motor vehicle crash. Daytime somnolence (p = 0.05) and early arousals (p = 0.001) were risk factors and daytime napping (p = 0.007) and benzodiazepines (p = 0.006) were protective. Improvement was achieved by changing the dosing schedule, the amount of agonist per dose, discontinuing the agonist or accommodating the sleepiness. We conclude that dopamine agonists are commonly implicated in IDS.