Almost 200 Australians who developed gambling and sexual addictions after taking prescription drugs used to treat Parkinson's disease will be awarded compensation over alleged failures to warn them about side-effects.

Drug manufacturer Pfizer this month agreed to settle with 160 Australians who took its drug Cabaser to treat tremors associated with Parkinson's disease or restless legs syndrome between 1996 and 2010.

Pat Galea, who suffers from Restless Legs Syndrome, was part of the class action against drug company Pfizer. Credit:Meredith O'Shea

The agreement, ahead of a class action due to be heard in the Federal Court, follows a settlement last year for 32 people in a similar action against Aspen Pharmacare and Eli Lilly over their drug Permax.

Patients are expected to share in millions of dollars' compensation, with some losing hundreds of thousands of dollars on gambling binges after taking the drugs despite not having prior gambling problems.