[Ropinirole in the treatment of Parkinson's disease: an update]

Ropinirole is a non-ergot dopaminergic agonist with a high affinity for D2 dopaminergic receptors which improves the symptoms of Parkinson's disease (PD) and delays the appearance of motor complications. It is different to the first generation of dopaminergic agonists in that, because it lacks an ergolinic structure, it does not have the side effects that usually appear with the use of this pharmacological group.

Recent functional neuroimaging studies suggest a possible neuroprotector effect of the drug, although this aspect is still under discussion. The question as to when and how early treatment of PD must be started has been a controversial issue for many years now. Dopaminergic agonists have been used in monotherapy in patients with de novo disease with the intention of deferring treatment with levodopa and, in consequence, postponing the onset of the complications stemming from its use. Ropinirole has been evaluated in different studies both in monotherapy and as adjunctive therapy with levodopa.

In the numerous clinical trials that were carried out, it would seem clear that ropinirole can be administered for years as sole early treatment for PD and that it offers a notable reduction in the appearance of dyskinesias. Given the linear dose-response relation it presents, the drug has a wide "therapeutic window" that allows the dosage to be increased as the disease progresses.