Increased life expectancy resulting from addition of L-deprenyl to Madopar treatment in Parkinson's disease: a longterm study.

In an open, uncontrolled study the longterm (9 years) effect of treatment with Madopar alone (n = 377) or in combination with l-deprenyl (selegiline, selective monoamine oxidase type B inhibitor) (n = 564) have been compared in Parkinsonian patients. In patients who lost their response to conventional Madopar therapy the addition of l-deprenyl resulted in a significant recouping of levodopa effect. The survival analysis revealed a significant increase of life expectancy in Madopar--l-deprenyl group regardless of the fact whether or not the significant demographic differences between the two groups were taken into account. Although the mechanism underlying this action of l-deprenyl is not known, the results are interpreted as indicating l-deprenyl's ability to prevent or retard the degeneration of striatal dopaminergic neurons. l-Deprenyl is the first anti-Parkinson drug having such a property. This hypothesis is not far fetched since l-deprenyl selectively prevents the degeneration of striatal dopaminergic neurons induced in animals by the illicit drug 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Since latter compound is known to cause Parkinsonism in man and primates or Parkinson-like neurochemical and pathological changes in other animals the implications of the present study involving monoamine oxidase activity and l-deprenyl are apparent.