The disadvantages of the levodopa monotherapy - comparable to other dopaminergic substances - are the dose-dependent development of dyskinesia in ON-phases, and bradykinesia and akinesia in OFF-phases, the latter being a sign of dopaminergic deficiency with a recurrence of Parkinson's symptoms.<h4>Aim of the study</h4>In order to omit the side effects of levodopa, we devised a combination therapy consisting of amantadine, a monoamine oxidase type B-inhibitor and a dopamine agonist. The gene discussed is MAOB; the disease is Parkinson disease.