Piribedil

General information

Piribedil is a piperazine derivative, a non-ergot dopamine receptor agonist, whose pharmacology is unusual, in that it is an agonist at D ₂ and D ₃ receptors and an α ₂ -adrenoceptor agonist. It has been used for about 40 years in the treatment of Parkinson’s disease, including drug-induced parkinsonism [ ], but has received comparatively little attention. It has also been recommended for the treatment of patients with intermittent claudication [ , ], degenerative retinal vasculopathies [ ], depression [ , ], and restless legs syndrome [ ], memory impairment [ ].

Somnolence is a common adverse reaction to piribedil and it can occur at low doses [ ]. At higher doses gastrointestinal reactions (anorexia and nausea) occur in 13% of patients taking a gradually increasing dose up to 120 mg/day [ ]. At very high doses (240 mg/day), changes in liver function tests occasionally occur. After intravenous administration (1.5–3.0 mg/hour for 6 hours) drowsiness, cold extremities, and spontaneous erections are common [ ].

Drug studies