Reserpine (Rauwolfia sp.)
Reserpine is extracted from the root of Rauwolfia serpentina or Rauwolfia vomitoria, shrubs or small trees found in India and Africa. In traditional Indian herbal medicine, the root was brewed as a tea and used to treat hypertension, insanity, snakebite, and cholera. It was the first drug found to interfere with the human sympathetic nervous system, and its mode of action has been imitated in a number of pharmaceuticals used in the control of hypertension.
Reserpine is a sedative and also reduces the output of the heart and relaxes blood vessels, both resulting in reduced blood pressure. Only a small dose is required to achieve results and to avoid side effects. Nasal congestion is the most common side effect.