MAO- A- hæmmere, tricykliske antidepressiva, noradrenalin- reuptake- hæmmere som f. eks. desipramin, maprotilin og venlafaxin og lægemidler, som metaboliseres via COMT (f. eks. katekollignende forbindelser, paroxetin).
A significant number of Parkinson's disease patients have been treated with the combination of levodopa, carbidopa and entacapone with several active substances including MAO-A inhibitors, tricyclic antidepressants, noradrenaline reuptake inhibitors such as desipramine, maprotiline and venlafaxine and medicinal products that are metabolised by COMT (e. g. catechol-structured compounds, paroxetine).