A medication taken to lower high blood pressure (antihypertensive) that can cause Parkinson’s-like symptoms. The risk for experiencing those symptoms is high enough, and there are so many alternative antihypertensive medications, that people with Parkinson’s disease generally should not use reserpine. Doctors sometimes prescribed reserpine to take advantage of this side effect, in fact, to reduce dyskinEsias in neurode-gEnErativE conditions such as Huntington’s disease or in tardive dyskinesia before other medications became available. And this side effect made it possible to create the first laboratory model of Parkinson’s, a crucial step in understanding the disease’s pathological process and developing effective treatments.
Reserpine became available in 1952 as one of the first drugs to treat hypertension after it was isolated as the active ingredient in a botanical remedy, rauwolfia (snakeroot), that had long been used in herbal medicine to treat high blood pressure. Rauwolfia also was known to have a powerful sedative effect and was given to calm people who had severe psychiatric disorders. This effect intrigued the Swedish neuroscientist Arvid Carlsson, who began investigating the relationship between reserpine and serotonin and norEpinEphrinE, brain nEu-rotransmittErs related to emotion and mood.
During his research, Carlsson serendipitously discovered that high dosages of reserpine administered to laboratory animals caused the development of tremors and bradykinEsia (slowed muscle response), the hallmark symptoms of Parkinson’s disease. Following this trail led Carlsson to recognize that dopamine is an independent neurotrans-mitter; previously scientists had believed it to be solely a norEpinEphrinE precursor. From Carlsson’s work evolved the current understanding of Parkinson’s disease as the consequence of dopaminErgic neuron death and dopamine depletion in the brain and of current treatment regimens based on dopamine replacement with levodopa. Carlsson shared the 2000 Nobel Prize in medicine or physiology for his groundbreaking work that started with reserpine.
As a plant alkaloid, reserpine has numerous side effects in addition to its tendency to cause Parkinson’s-like symptoms, including potentially serious cardiac arrhythmias (irregular heartbeat) and depression. It also interacts with numerous medications, in particular levodopa. Reserpine cannot be taken with the antidEpressant medication class MONOAMINE OXIDASE INHIBITORS (MAOIs) and the selective MAO-B inhibitor selEgiline, which some people with Parkinson’s take for its neuroprotective effect, or with tricyclic antidepres-sants and selective serotonin rEuptake inhibitor (SSRI) antidepressants.
Reserpine is available in numerous products, some of which combine it with a diuretic such as hydrochlorothiazide. Common brand name products include Ser-Ap-Es, Regroton, Hydropres and Salutensin.