Reserpine is a naturally occurring drug that has been used for centuries in ancient India. It is extracted from the root of Rauwolfia serpentina or Rauwolfia vomitoria, plants found in India and Africa. In traditional herbal medicine, the root was brewed as a tea and used in humans to treat hypertension, insanity, snakebite, and cholera. The purified alkaloid, reserpine, was isolated in 1952 and is considered the first modern drug for the treatment of hypertension.
Reserpine irreversibly binds to the storage vesicles of neurotransmitters, particularly norepinephrine, serotonin and dopamine. Eventually, catecholamine depletion occurs because of the body’s inability to store these neurotransmitters. It is an unusual drug; it takes many hours or days to reach full effect and continues to have some subtle sedating effects for many days after the last dose.