The effectiveness and tolerance of piribedil as adjunct therapy to levodopa in patients with Parkinson's disease: a nine month follow up

Background: Piribedil is a D2 D3 dopamine agonist, which has been shown to be well tolerated and to improve Parkinsonian symptoms, particularly tremor. However, few studies have been published about this Dopamine Agonist as an adjunct to levodopa therapy in patients with Parkinson's disease (PD). This placebo controlled, parallel group study was undertaken to investigate the effects of piribedil in PD patients insufficiently controlled with levodopa in a nine months follow up.

Methods: We included 62 PD patients insufficiently controlled with levodopa and needed an increase in dopamine stimulation. Patients were randomized in two similar groups, one of them taking Piribedil and levodopa and the other group taking a placebo and levodopa. The primary efficacy measures were the items II and III of the UPDRS. The patients were evaluated prior to the start of therapy, and 3, 6 and 9 months after the start of the study.

Results: Patients taking Piribedil showed an average of improvement of 37,8% (p < 0.01) in the part II and 63,2% (p < 0.01) in the part III of the UPDRS at the end of the study. At 9 month evaluation, tremor at rest showed an average improvement of 68,6%, rigidity, fingers taps and legs agility improved substantially in their respective items of the UPDRS at the end of the study.

Conclusions: We concluded that PD patients with functional worsening while on stable levodopa doses exhibit a steady improvement of the UPDRS part II and III with the adjunction of Piribedil 150 mg mean daily dose for 9 months.