Treating Parkinson's disease at an early stage with the dopamine agonist cabergoline can significantly reduce the risk of developing motor complications, while maintaining symptom control, according to new data. In newly diagnosed patients treated with cabergoline alone, the risk of developing motor complications was 50 per cent lower than if only treated with levodopa.
The results of a five-year trial of 419 patients were presented recently at the International Congress on Parkinson's disease in Canada. Patients received cabergoline (up to 4mg a day) or levodopa (up to 600mg a day). Pharmacia & Upjohn, the manufacturer of cabergoline (Cabaser), said in a press statement that it hoped to extend the licence for Cabaser to include use in early disease. At present, the drug is only licensed for the treatment of advanced Parkinson's disease in combination with levodopa.
Previous clinical trial data have suggested that another dopamine agonist, ropinirole, could be used first-line in the treatment of Parkinson's disease (PJ, July 31, p150).
Dr John O'Sullivan (clinical research fellow, National Hospital for Neurology and Neurosurgery, London) told The Journal on September 2: "The early use of dopamine agonists is further supported by these studies." He believed that all dopamine agonists would have similar effects. There was no evidence to suggest that patients already taking levodopa would do better if changed to a dopamine agonist, Dr O'Sullivan said.
In a newly diagnosed patient, dopamine agonists should "at least be considered" but it would not be appropriate to suggest that all patients should receive them. In many patients, levodopa would still be appropriate, he said.