Selegiline is a selective MAO-B inhibitor which prevents dopamine breakdown in the brain. It also inhibits the re-uptake of dopamine at the pre-synaptic dopamine receptor. These effects potentiate dopaminergic function in the brain and help to even out and prolong the effect of exogenous or endogenous dopamine.
Recent studies have demonstrated that use of Selegiline in previously untreated patients can delay the development of disability and prolong the time before levodopa therapy is required. Selegiline potentiates and prolongs the effect of levodopa in the treatment of parkinsonism. The addition of Selegiline to levodopa (with or without decarboxylase inhibitor) therapy helps to alleviate dose related fluctuations and end-of-dose deterioration. At a later stage in the disease it can also smooth the symptoms of the on/off effect.
Unlike conventional MAO inhibitors, which inhibit both the MAO-A and MAO-B enzyme. Selegiline is a specific MAO-B inhibitor and can be given safely with levodopa. There are no dietary restrictions associated with Selegiline treatment, i.e. it does not cause the so called cheese effect.