Q. My niece told me that drinking tonic water helped her restless legs syndrome. I tried sipping some before I went to bed, and it helps.
After I read in your column that the FDA bars doctors from prescribing quinine, I looked on the label. Quinine is listed as one of the ingredients. Is quinine harmful?
A. Some people are susceptible to quinine and develop irregular heartbeats or a life-threatening blood disorder when they consume it. It can also cause birth defects. The FDA banned it for treating leg cramps to prevent the serious side effects it can cause. Doctors are still permitted to prescribe it for malaria.
The dose of quinine found in tonic water is low, but we heard from one reader who suffered a severe reaction from drinking it:
“One evening I drank 5 ounces of tonic water; the next morning I was in the emergency room with a frightening skin reaction. I was hospitalized for many days.
“My platelet count dropped to 1,000. Now it has gradually come back up to 266,000. I was diagnosed with ITP (idiopathic thrombocytopenic purpura), triggered by the quinine in the water. It nearly killed me.”