Quinine side effects include deafness, low blood platelets, and an irregular heartbeat. Use can make one more prone to sunburn. While it is unclear if use during pregnancy causes harm to the baby, use to treat malaria during pregnancy is still recommended. Quinine is an alkaloid, a naturally occurring chemical compound. How it works as a medicine is not entirely clear. Quinine was first isolated in 1820 from the bark of a cinchona tree. Bark extracts have been used to treat malaria since at least 1632. It is on the World Health Organization's List of Essential Medicines, the most effective and
Cinchona a strong decoction of the cinchona bark served with wine. Wine was used because some alkaloids of the cinchona bark are not soluble in water, but are soluble in the ethanol in wine. In 1681 "Água de Inglaterra" was introduced into Portugal from England by Dr. Fernando Mendes who, similarly, “received a handsome gift from (King Pedro) on condition that he should reveal to him the secret of its composition and withhold it from the public”. In 1738, "Sur l'arbre du quinquina", a paper written by Charles Marie de La Condamine, lead member of the expedition, along with Pierre Godin