Drug interactions with selegiline versus rasagiline

In patients with Parkinson’s disease (PD), long-term, successful use of a medication is not only determined by its efficacy, but also by its therapeutic safety and tolerability. This is especially relevant when two effective medications from the same class of active substances are available, in our case two monoamine oxidase B inhibitors (MAO-BI): Rasagiline and selegiline. The monitoring, collection, analysis and reporting of information for drug safety (“pharmacovigilance”) are receiving increasing attention. Ever increasing demands are placed on the establishment of faster lines of communication between physicians, the pharmaceutical industry and the supervising authorities for reporting and investigating adverse events. Neglect or delay in the communication of serious side effects can also – even after introduction onto the market – entail immediate sanctions, extending to authorisation restrictions or revocation of the authorisation. Hence the broad application of budipine was considerably restricted due to its possible prolongation effect on the QT interval, cisapride was removed from the market and cabergoline and pergolide may only now be used as second-line dopamine agonists. It is not generally known to the physicians that adverse effects of a medication are frequently caused by interactions with other drugs. As a chronic progressive neurodegenerative illness, PD necessitates lifelong continual treatment with a highly complex combination of active substances. Adding to this are concomitant diseases requiring treatment and the generally advanced age of the patients. The main focus of the present work is to demonstrate possible drug interactions described in the literature when using rasagiline and selegiline, which could lead either to limitation in efficacy or to potential harm to the patient through an unforeseen alteration of efficacy. In addition, differences in the interaction potential of both MAO inhibitors are addressed.