To determine whether adding orally disintegrating selegiline (ODS) while decreasing dopamine agonist (DA) dosages would reduce DA-related adverse effects (AEs) of excessive daytime sleepiness (EDS), pedal edema, hallucinations, and impulse control disorders (ICDs) without compromising efficacy in Parkinson disease (PD) patients.

This was a 12-week open-label study of 60 PD patients with motor fluctuations and DA-related AEs of EDS, pedal edema, hallucinations, and ICDs. Orally disintegrating selegiline was initiated at 1.25 mg once daily, and down titration of the DA was started with a goal of a 50% reduction by 1 week. At week 6, ODS was increased to 2.5 mg, and further reductions of the DA were allowed if the AEs were not resolved.

The addition of ODS allowed a reduction in the mean daily dose of pramipexole from 2.3 to 0.5 mg and immediate-release ropinirole from 11.2 to 2.9 mg. Most subjects reported a reduction or resolution of DA-related AEs; 94% with EDS (n = 50), 73% with pedal edema (n = 26), 86% with hallucinations (n = 15), and 84% with ICDs (n = 25). Mean activities of daily living and motor scores from the Unified Parkinson's Disease Rating Scale as well as quality-of-life scores were significantly improved without an increase in daily "off" time. The most common AEs, most of which resolved after titration, were worsening of PD, nausea/vomiting, dyskinesia, increased off time, body aches, insomnia, orthostatic hypotension, and increased anxiety and depression.

In most subjects, the addition of ODS with decreasing dosages of DAs substantially reduced EDS, pedal edema, hallucinations, and ICDs without compromising efficacy.