Copyright People’s Pharmacy

Q: For years, I’ve suffered severe muscle spasms all over m body.  One cramp would begin, and I’d stretch the muscle to try to rid myself of it.  No sooner would it start to relax than another would begin.  The pain would be excruciating, with tears and exhaustion following.  My doctor did not seem very concerned, although he prescribed muscle relaxers.  These never did help, even when he doubled the dose and I took them three times a day.  I often wondered how I could continue to live this way.  Finally, someone suggested tonic water, and it changed my life.  I can’t believe the relief I’ve gotten,  Each night I open a can of tonic water and let it sit because carbonation bothers me.  Once it is flat, I drink the full can and haven’t suffered a cramp since.

A: We used to think that the small amount of quinine (20mg) in a glass of tonic water would be inadequate to prevent or treat muscle cramps.  That’s because doctors used to prescribe 200 to 300mg of quinine for patients with leg cramps.  Nonetheless, many readers have stories similar to yours.  We now think we have figured out the explanation.  Quinine stimulates a specialized channel on cell membranes called TRPM7.  Such transient receptor potential  (TRP) channels are found on nerves throughout the body.  Activating them through the TRP channels appears to reverse the nerve hyperactivity that causes muscle cramps.  Other things that also trigger TRP channels include vinegar, ginger, garlic and chili peppers.