Discontinuation of ropinirole and pramipexole in patients with Parkinson's disease: clinical practice versus clinical trials

Objective To compare characteristics and incidence of discontinuation of Parkinson's disease (PD) patients starting ropinirole or pramipexole in clinical practice with data from randomised controlled clinical trials (RCTs). Methods Included in the retrospective clinical-practice cohort were first-time users of ropinirole or pramipexole diagnosed with PD before 2005. Baseline characteristics and incidence of discontinuation were compared between the clinical-practice cohort and RCTs. Treatment discontinuation was defined as more than 180 days between two refills of ropinirole or pramipexole. The incidence of discontinuation in RCTs was based on the reported rate of discontinuation for any cause. Results Included were 45 patients who started with ropinirole and 59 patients who started with pramipexole. Treatment was discontinued within 3 years in 51% ( ropinirole) and 60% ( pramipexole) of the patients. Ten RCTs with ropinirole and 12 with pramipexole were identified. Baseline characteristics did not differ between the clinical-practice cohort and RCTs. RCTs reported discontinuation rates comparable with those at the same timepoint in the clinical practice until 1 year of follow-up. Conclusion This study shows that the overall incidence of discontinuation of ropinirole and pramipexole between the patients in our clinical-practice cohort and patients in the RCTs was comparable for the short term. However for the long term, discontinuation in practice is possibly higher.