text: The first commercial tonic water was produced in 1858 when it was patented by the owner of Pitt & Co., Erasmus Bond. The mixed drink gin and tonic also originated in British colonial India, when the British mixed their medicinal quinine tonic with gin and other ingredients to make the bitter medicine more palatable. Soldiers in India were already given a gin ration, so the sweet concoction was easy to make. In 1868, the first known record of a gin and tonic was in the Oriental Sporting Magazine and was described as a refreshing cocktail for spectators of horse racing, not as a medicine.
  Quinine content
  Medicinal tonic water originally contained only carbonated water and a large amount of quinine. Most modern tonic waters contain comparatively less quinine, and are often enhanced by citrus flavors. As a result of the lower quinine content, tonic water is less bitter. It is also usually sweetened, often with the addition of high-fructose corn syrup or sugar. Some manufacturers also produce diet (or "slimline") tonic water, which may contain artificial sweeteners, such as aspartame. Traditional-style tonic water with high amounts of quinine and carbonated water is less common, but may be preferred by those who desire the bitter flavor.
  In the United States, the US Food and Drug Administration (FDA) limits the quinine content in tonic water to 83 ppm (83 mg per liter), while the daily therapeutic dose of quinine is in the range of 500–1000 mg, and 10 mg/kg every eight hours for effective malaria prevention (2,100 mg daily for a  adult). Until about 2010, quinine was often recommended as a relief for leg cramps, although medical research suggested some care was needed in monitoring doses. Because of quinine's risks, the FDA cautions consumers against using "off-label" quinine drugs to treat leg cramps.