Impact of deprenyl and tocopherol treatment on Parkinson's disease in DATATOP subjects not requiring levodopa. Parkinson Study Group.

In the controlled trial Deprenyl and Tocopherol Antioxidative Therapy of Parkinsonism (DATATOP), 310 of the 800 enrolled subjects did not reach the primary end point of disability requiring levodopa therapy during 21 +/- 4 (mean +/- SD) months of observation or need early initiation of deprenyl (selegiline) during a 2-month withdrawal of experimental treatments. While maintaining the blindness of their original deprenyl and tocopherol treatment assignments, these 310 subjects were administered deprenyl 10 mg/day (open label) and were monitored systematically at 1- to 3-month intervals for up to 18 months (12 +/- 5 mo). During this extended trial, the 189 subjects who had been assigned originally to active deprenyl tended to reach the end point of disability faster than the 121 subjects who had not been assigned originally to deprenyl (hazard ratio, 1.43; 95% CI, 0.98, 2.09; p = 0.065). However, the differential rates of reaching the end point may have been due in part to the more severe baseline impairment of deprenyl-assigned subjects, who benefited originally from deprenyl but who were more likely to require levodopa during this extended period of observation. Prior treatment with deprenyl did not lead to superior survival with respect to the end point of disability requiring levodopa, suggesting that the initial advantages of deprenyl were not sustained.