Activity and acceptability of piribedil in Parkinson's disease: a multicentre study
Several controlled trials have shown that the dopamine agonist, Trivastal (piribedil), is active in the treatment of Parkinson's disease, particularly with regard to tremor. To determine its efficacy as monotherapy in patients previously untreated with levodopa, a 3-month multicentre study was conducted with Trivastal 50 mg LP in 113 patients with idiopathic Parkinson's disease. The study population consisted of 66 men and 47 women, aged 63.1, SD 0.6 (43–79) years with a 2.1, SD 0.2 (1–15) year history of Parkinson's disease. Mean disease stage was 1.82 (1–4) by the Hoehn and Yahr classification. Tremor was the predominant clinical feature in 42 patients; the remaining 71 patients displayed the full parkinsonian syndrom. Trivastal 50 mg LP was prescribed stepwise up to doses of 150–250 (207, SD 6.4) mg/day at the end of 3 months. No concomitant antiparkinsonian medication was given. Patients were clinically assessed at 1, 2 and 3 months on the Webster scale, a specific tremor scale and the HARD depression scale. Mean results were as follows in the 90 patients completing the study. On the Webster scale, tremor fell from 1.7 to 1 (−41%,P<0.001), bradykinesia from 1.5 to 0.8 (−47%,P<0.001) and rigidity from 1.3 to 0.9 (−31%,P < 0.001); on the specific scale, rest tremor decreased in daily duration and amplitude from 3.9 to 2.4 (−39%,P < 0.001) and from 2.9 to 2.1 (−35%,P < 0.001), respectively. The 32 patients in whom tremor was the predominant feature improved their total score on the Webster scale from 5.8 to 4.7 (−19%,P<0.05) and their tremor score from 1.7 to 1.2 (−29%,P < 0.05). The 58 patients with the full parkinsonian syndrom improved their total Webster score from 11.8 to 6.9 (−42%,P < 0.001). Eight of the ten items on the scale were significantly reduced, from between 33% (facial expression) to 53% (manual bradykinesia). The depression rating fell from 10.2 to 7.3 (P < 0.001), the most marked improvement being in mood and inhibition. In conclusion, monotherapy with Trivastal 50 mg LP at a mean dose of 200 mg/day is effective within 1 month regarding the major features of Parkinson's disease.