Quinine giving a further half dose. No injectable preparation of quinine is licensed in the US; quinidine is used instead. Quinine is a flavor component of tonic water and bitter lemon drink mixers. On the soda gun behind many bars, tonic water is designated by the letter "Q" representing quinine. According to tradition, the bitter taste of anti-malarial quinine tonic led British colonials in India to mix it with gin, thus creating the iconic gin and tonic cocktail, which is still popular today. Nowadays, the amount of quinine in tonic is much lower and drinking it against malaria is useless. Quinine
Human genetic resistance to malaria as in other diseases, innate immunity leads into, and stimulates, adaptive immunity. Mutations may have detrimental as well as beneficial effects, and any single mutation may have both. Infectiousness of malaria depends on specific proteins present in the cell walls and elsewhere in red blood cells. Protective mutations alter these proteins in ways that make them inaccessible to malaria organisms. However, these changes also alter the functioning and form of red blood cells that may have visible effects, either overtly, or by microscopic examination of red blood cells. These changes may impair the function of red blood cells in various