GlaxoSmithKline could face legal action after its Requip drug, taken by Parkinson’s disease sufferers, was said to cause gambling addiction.

A man from the UK is the latest patient to complain about the drug, saying that he became addicted to internet gambling and attempted suicide three times after he was first treated with the medicine eight years ago.

Since 2003, an increasing number of Parkinson’s sufferers in the UK, the US and Europe have complained of obsessive behaviour, developed after taking dopamine agonists such as pramipexole, cabergoline, pergolide and ropinirole (Requip).

The undesired side effects of Requip have been known for years, but a warning only appeared inside its packaging in 2006.

The man is seeking damages from GlaxoSmithKline, which he accuses of selling a ‘defective’ drug, and from his neurologist, for not properly informing him about Requip.