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.