Long-term safety and sustained efficacy of extended-release pramipexole in early and advanced Parkinson's disease.

BACKGROUND AND PURPOSE: To assess the long-term safety and efficacy of pramipexole as a once-daily (q.d.) extended-release oral formulation in early or advanced Parkinson's disease (PD). METHODS: In two double-blind (DB) studies of early PD and one of advanced PD,active-treatment arms received pramipexole immediate release (IR) or extended release (ER), with exposure lasting up to 33 weeks. In open-label (OL) extensions that followed immediately, subjects took ER q.d. for up to 80 weeks, with dosage adjustment permitted (range 0.375-4.5 mg q.d.). RESULTS: Of 590 subjects completing an early-PD DB study, 511 entered the early-PD OL extension; 408 completed it. Reported adverse events (AEs) with incidence ≥10.0% were somnolence (15.1%), peripheral edema (11.7%) and back pain (10.6%). Of 465 subjects completing the advanced-PD DB study, 391 entered the advanced-PD OL extension; 329 completed it. Reported AEs with incidence ≥10.0%were dyskinesia (27.4%) and somnolence (13.6%). Impulse control disorders were identified by semi-structured interview in 13 subjects (1.4% of 902). In exploratory analyses, adjusted mean Unified Parkinson's Disease Rating Scale (UPDRS) PartsII + III scores (excluding ex-placebo recipients) remained substantially improved from DB baseline scores prior to pramipexole introduction, at -6.6 and -6.3 points amongst ex-DB-ER and ex-DB-IR recipients after 113 weeks of pramipexole (33 DB plus 80 OL) in early PD, and -11.5 and -9.1 after up to 113 weeks (up to 33 DB plus 80 OL) in advanced PD. CONCLUSIONS: These results support the long-term safety and efficacy of pramipexole ER in early and advanced PD. AEs were typical for dopaminergic medications, and UPDRS scores suggested sustained symptomatic benefit.

Patient-reported convenience of once-daily versus three-times-daily dosing during long-term studies of pramipexole in early and advanced Parkinson's disease.

BACKGROUND AND PURPOSE: In chronic diseases including Parkinson's disease (PD), complex pharmacotherapy dosing schedules are reported to reduce adherence, perhaps leading to less-effective symptom control and, in PD, more erratic stimulation of dopamine receptors. However, blinded clinical-trial designs preclude direct comparisons of adherence to various schedules. METHODS: In two double-blind (DB) studies of early PD and one of advanced PD, subjects received three-times-daily (t.i.d.) pramipexole or placebo. In open-label (OL) extensions, subjects took extended-release, once-daily (q.d.) pramipexole. At 24 or 32 OL weeks, q.d. versus t.i.d. dosing preference was surveyed by questionnaire. RESULTS: Of 590 DB-trial completers with early PD, 511 entered the OL extension. Of 374 survey respondents, 94.4% preferred q.d. dosing (72.2% of them found it 'very much more convenient' and 27.8%'more convenient'), 2.7% preferred t.i.d., and 2.9% chose 'no difference'. Of 465 DB-trial completers with advanced PD, 391 entered its OL extension. Of 334 survey respondents, 88.9% preferred q.d. dosing (59.9% of them found it 'very much more convenient' and 40.1%'more convenient'), 5.7% preferred t.i.d., and 5.4% chose 'no difference'. Results excluding DB-placebo recipients were highly similar. CONCLUSIONS: In this first direct comparison of patient preference for q.d. versus t.i.d. dopamine-agonist dosing, patients with early or advanced PD had a strong preference for q.d. rather than t.i.d. pramipexole. The high proportion of advanced-PD patients declaring this preference indicates that it does not depend on whether a patient is taking concomitant PD medications dosed more frequently than q.d.

Success rate, efficacy, and safety/tolerability of overnight switching from immediate- to extended-release pramipexole in advanced Parkinson's disease.

BACKGROUND AND PURPOSE: For Parkinson's disease (PD), an extended-release (ER) pramipexole formulation taken once daily, has shown efficacy, safety, and tolerability resembling those of immediate-release (IR) pramipexole taken three times daily. The present study assessed, in advanced PD, the success of an overnight switch from adjunctive IR to ER. METHODS: Levodopa users experiencing motor fluctuations were randomized to adjunctive double-blind (DB) placebo, IR, or ER. Amongst completers of ≥18 weeks, ER recipients were kept on DB ER, whilst IR recipients were switched overnight to DB ER at unchanged daily dosage. After a DB week, switch success was assessed. During the next 5 weeks, all patients underwent ER titration to optimal open-label maintenance dosage. RESULTS: One week post-switch, 86.2% of 123 IR-to-ER and 83.8% of 105 ER-to-ER patients had ≤15% (or ≤3-point, for pre-switch scores ≤20) increase on UPDRS Parts II + III, and 77.9% (of 122) and 70.2% (of 104) had ≤1-h increase in daily OFF-time. At 32 weeks, the groups showed comparable improvements from DB baseline (pramipexole inception), including, on UPDRS II + III, adjusted mean (SE) changes of -14.8 (1.5) for IR-to-ER and -13.3 (1.6) for ER-to-ER. Rates of premature discontinuation owing to adverse events were 6.5% for IR-to-ER and 4.9% for ER-to-ER. CONCLUSIONS: By OFF-time and UPDRS criteria, majorities of patients with advanced PD were successfully switched overnight from pramipexole IR to ER at unchanged daily dosage. During subsequent maintenance, pramipexole showed sustained efficacy, safety, and tolerability, regardless of formulation (IR or ER) in the preceding DB trial.