Current controversies in the use of selegiline hydrochloride

Selegiline hydrochloride (-)-deprenyl is now established as a safe and valuable adjuvant therapy in the management of Parkinson's disease. About fifty per cent of patients with mild levodopa-induced fluctuations are improved by the addition of 10 mg a day of selegiline and there may be associated relief of nocturnal and early morning disabilities. This effect is usually apparent within a week of starting treatment and is sustained in the majority of responders for at least one year, after that oscillations progressively return. Compared with other anti-parkinsonian drugs this medication is relatively easy to use and has few adverse side-effects. Unlike conventional monoamine oxidase inhibitors, dietary restrictions of tyramine are unnecessary and rises in blood pressure do not occur when it is used together with L-dopa. Selegiline also has mild L-dopa sparing effects (100-200 mg per day) and it may also increase alertness, drive and motivation (Lees et al., 1977). Some of the more controversial issues relating to selegiline will be discussed in this article.