Q. Since quinine sulfate is no longer available for leg cramps, I wonder if there is any danger in drinking “tonic water” just for the flavor. Quinine is an ingredient, I believe.
A. Although the FDA has banned the use of prescription quinine pills to treat leg cramps, the agency has not proposed eliminating tonic water from the market. If it did, a lot of people who enjoy gin and tonic might revolt.
Readers aware of the quinine in tonic water have put it to use: “I have been drinking tonic water with quinine for about two months now, and my leg and foot cramps have disappeared completely.”
FDA banned quinine from use against leg cramps because sensitive people may develop a potentially deadly blood disorder in reaction to quinine. Although this complication is rare, it is extremely serious. One reader reported being hospitalized after drinking a 5-ounce glass of tonic water. She developed a terrible skin reaction and her blood platelets plummeted. She was told that in her case even a drop could be lethal.