The dopamine agonist piribedil with L-DOPA improves attentional dysfunction: relevance for Parkinson's disease.

Cognitive deficits are often associated with motor symptoms in Parkinson's disease. This study investigates the ability of piribedil ([(methylenedioxy-3,4 benzyl)-4 pyperazinyl-1]-2 pyrimidine), a D(2)/D(3) dopamine (DA) receptor agonist with antagonist activity at alpha(2A)-adrenoceptors, to restore motor and attentional deficits in nigrostriatal 6-hydroxydopamine-lesioned rats. Subjects were trained to depress a lever, detect a stimulus occurring after variable foreperiods, and release the lever quickly afterward.

Repeated administration of piribedil induces less dyskinesia than L-dopa in MPTP-treated common marmosets: a behavioural and biochemical investigation.

Piribedil ([1-(3,4-methylenedioxybenzyl)-4-(2-pyrimidinyl)piperazine]; S 4200) is a dopamine agonist with equal affinity for D(2)/D(3) dopamine receptors effective in treating Parkinson's disease as monotherapy or as an adjunct to levodopa (L-dopa). However, its ability to prime basal ganglia for the appearance of dyskinesia is unknown. We now report on the ability of repeated administration of piribedil to induce dyskinesia in drug naïve 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) -lesioned common marmosets compared with L-dopa and its actions on the direct and indirect striatal outflow pathways.