Background: Although dopamine agonists (DAs) are useful in Parkinson's disease (PD), they are not frequently used in elderly patients due to adverse effects. However, there is a lack of evidence because few elderly PD patients are enrolled in clinical trials.
Aims of the study: The aims of this study were to analyze the reasons of DA withdrawal (DAW) in a group of PD patients in clinical practice and to identify the related factors. Specifically, we studied the effect of age, comorbidity, and polypharmacy as potential risk factors for DAW.
Methods: A retrospective chart review of the follow-up (from May, 2012 to March, 2015) of a subgroup of PD patients receiving a DA (n = 68; 60.3% males, 69.3 ± 9.2 years old) from a cohort (n = 150) previously studied in detail in 2012 was used to identify predictive factors of DAW.
Results: The DAW percentage was 18.2% (12/66; follow-up of 690.2 ± 232.6 days). DAW causes were cognitive impairment (3), reduction therapy (3), hallucinations (2), dyskinesia (2), and excessive diurnal somnolence (2). Only a higher levodopa daily dose (HR 1.003; 95% CI 1.001-1.006; P = 0.044) was an independent predictor of DAW after adjustment for other explanatory variables.
Conclusions: The frequency of DAW was low. Advanced age alone is not a contraindication to the administration of DAs.
Keywords: Age; Parkinson′s disease; comorbidity; dopamine agonist; polypharmacy; tolerability.