Parkinson's drugs causing serious behavioural problems

The major drugs for treating Parkinson’s disease are causing compulsive behavioural problems in around 22 per cent of all patients, a new study has discovered.
Mirapex (pramipexole) and Requip (ropinirole), both dopamine agonists, are responsible for a range of compulsive behaviours, including pathological gambling, hypersexuality, binge eating, spending and excessive computer use.
Researchers at the Mayo Clinic found a direct association between dose and behaviour – patients taking higher doses were more likely to have a behavioural problem.  
Around one in four patients had behavioural problems if they were taking a standard dose of one of the drugs, but the problem affected one in three patients on a higher dose.
Patients taking a dopamine agonist usually found their behaviour returned to normal within a month of stopping the treatment, say the Mayo researchers.
(Source: Parkinsonism & Related Disorders, 2011; doi: 10.1016/j.parkreldis.2011.01.009).