Dopamine Agonists

The enzymes responsible for synthesizing dopamine are depleted in the brains of Parkinsonism patients, and drugs acting directly on dopamine receptors may therefore have a beneficial effect additional to that of levodopa. There are a number of dopamine agonists with antiparkinsonism activity.

e.g: Bromocryptine

Monoamine Oxidase Inhibitors: Selegiline (deprenyl), a selective inhibitor of monoamine oxidase B, hinders the breakdown of dopamine; as a result, it prolongs the antiparkinsonism effect of levodopa. Selegiline has only a minor therapeutic effect on parkinsonism when given alone. It may reduce disease progression.