Unfortunately, I'm not convinced that any medication, including quinine, is effective for nighttime (nocturnal) leg cramps.

Although nighttime leg cramps are common, the cause is unknown. Besides aging, they are associated with flat feet, a sedentary lifestyle, dehydration and diabetes. Doctors tend to check electrolytes and minerals, including potassium, sodium, magnesium and calcium. However, a definite cause is rarely found.

Options for treatment include:

• Stretching
• Regular exercise
• Drinking plenty of fluids, especially around the time of exercise
• Applying heat (before or just after a cramp)
• Changing footwear, including using arch supports and good cushioning

Although unproven, a number of medications are often tried:

• Quinine
• Muscle relaxants (such as cyclobenzaprine)
• Diphenhydramine (Benadryl and many others)
• Verapamil
• Gabapentin

The Food and Drug Administration took action in late 2006 to limit the use of prescription quinine so that it is only used as a treatment for malaria. That's because studies suggest it does little to improve night cramps and it has some serious potential side effects, including an unstable heart rhythm, low blood counts and allergic reactions. It can also cause trouble by interacting with other medicines.

Although nocturnal leg cramps are not dangerous, they are quite painful and they disrupt sleep, so see your doctor for an evaluation. Your doctor will look for a specific cause of your leg cramps and review treatment options with you.