About Ropinirole A non-ergoline Dopamine Agonist, Anti-Parkinson`s Agent. Mechanism of Action of Ropinirole Ropinirole is a non-ergoline Dopamine agonist. The antiparkinsonian activity is due to stimulatory effect on post synaptic Dopamine receptors (D2) within the caudate- putamen. It has affinity for other dopamine receptors such as D3 &D4. Ropinirole also has moderate invitro affinity for opioid receptors. Ropinirole and its metabolite has very little affinity for D1, 5HT1, 5HT2,Benzodiazepines, GABA, muscarinic, alpha and beta adreno receptors. Indications for Ropinirole 1. Parkinson`s disease - idiopathic Parkinson`s disease. Interactions for Ropinirole Oestrogens decrease the oral clearance of ropinirole thereby increasing its plasma levels. Cimetidine, ciprofloxacin, Diltiazem and Mexiletene increase its levels by altering the clearance. Phenothiazines and butyrophenones decrease its effectiveness.