Dopamine agonists have shown a strong association with incident impulse control disorders in patients with Parkinson disease, according to a study published in Neurology. Discontinuing dopamine agonists resulted in the progressive resolution of impulse control disorders.
This study included 411 individuals, 40.6% of whom were women, with a mean age of 62.3 years. In this cohort, 356 patients (86.6%) used a dopamine agonist a minimum of 1 time since the onset of Parkinson disease. The incidence of impulse control disorders over 5 years was 51.5% in dopamine agonist ever-users (95% CI, 41.8 to 62.1) and 12.4% in dopamine agonist never-users (95% CI, 4.8 to 30.0), yielding a cumulative incidence of 46.1% (95% CI, 37.4 to 55.7). Impulse control disorders grew more prevalent over 5 years after baseline, increasing from 19.7% to 32.8%, and showed an association with dopamine agonist ever use (prevalence ratio, 4.23; 95% CI 1.78 to 10.09). Impulse control disorders showed an independent association with lifetime average daily dose of dopamine agonists and length of treatment.
The average follow-up period for this study was 3.3 years. Data were drawn from a longitudinal cohort of individuals with a minimum of 5-year duration of Parkinson disease. Movement disorders specialists performed assessments of impulse control disorders through in-person interviews. The study researchers utilized Poisson models and generalized estimating equations to evaluate the correlation between several factors of dopamine agonist use. These definitions accounted for length of treatment, dose, and use of other drugs for Parkinson disease. Impulse control disorders were assessed during every visit.
The study researchers conclude that, “[In] this longitudinal study of patients with [Parkinson disease] characterized by a high prevalence of [dopamine agonist] treatment, the 5-year cumulative incidence of [impulse control disorders] was [approximately] 46%. [Impulse control disorders] were strongly associated with [dopamine agonist] use with a dose-effect relationship; both increasing duration and dose were associated with [impulse control disorders]. [Impulse control disorders] progressively resolved after [dopamine agonist] discontinuation.”
Corvol JC, Artaud F, Cormier-Dequaire F, et al; for the DIGPD Study Group. Longitudinal analysis of impulse control disorders in Parkinson disease [published online June 20, 2018]. Neurology. doi: 10.1212/WNL.0000000000005816