The Food and Drug Administration has banned the use of quinine to treat leg cramps. Although this drug has been available for centuries, the FDA has determined that it is far too dangerous to use for anything but malaria.
The trouble is that some people are extremely sensitive to quinine’s toxic effects. This drug can cause headache, rash, ringing in the ears, nausea, dizziness and blurred vision.
The most serious reactions are rare but can be life threatening. Blood disorders can lead to hemorrhaging. Dozens of hospitalizations and two deaths are linked to quinine.
Clearly, quinine can be dangerous for certain people, but the FDA has not banned quinine from tonic water. Quinine gives this beverage its distinctive flavor. Either the FDA doesn’t consider tonic water a danger to public health or the agency worries about arousing the ire of millions of gin and tonic drinkers.
Because of this loophole, many people have discovered that drinking tonic water can help prevent muscle cramps. One reader related her experience: “I suffered with nightly leg cramps until one magic day on the Greek island Santorini. I had gone on tour as a guest singer of the New York Choral Society. One free afternoon, a group of us went to a black sand beach where I swam. The only other member of the group who also swam was a New York trauma surgeon. I developed a cramp and was trying to walk it out when he told me about Schweppes tonic, which contains a very small amount of quinine.
“I couldn’t find any tonic on Santorini or in Athens, but as soon as I returned home I started drinking a large glass (diet, with cranberry) every night. It has worked for me for several years, but I definitely know if I skip a dose!
“I asked a pharmacist friend to search the literature to see if anything else contains a small amount of quinine. She couldn’t find anything and told me the dangers of using high-dose quinine. I have checked with my doctors and have heard nothing against my practice of drinking Schweppes.”
Tonic contains 83 mg. of quinine in a liter. An eight-ounce glass or tonic would only have about 20 mg of quinine, considerably less than the dose that used to be prescribed for leg cramps (200 to 300 mg).
Despite the low dose, however, many readers maintain that it works: “My doctor recommended tonic water for nocturnal leg cramps. It works every time very quickly. In less than five minutes I get relief and can go back to sleep. I suffer NO pains if I drink half a glass before I go to bed.”
Some people find even the small amount of quinine in tonic water can pose problems. These folks may experience ringing in the ears, rash, itching or blurred vision and should steer clear of tonic water altogether.
For such people, home remedies may be the best way to get relief from nocturnal leg cramps. Our Guide to Leg Pain has instructions on stretching as well as a range of remedies.