Quinine taken medicinally can prevent leg cramps, but patients should view it as a last resort due to its potential dangers, advises Patient.co.uk. While the low doses of quinine typically prescribed for leg cramps usually do not produce side effects, any side effects experienced can be severe.
Taking sufficient amounts of calcium and magnesium can also help prevent leg cramps as can staying adequately hydrated, as MedicineNet indicates. Taking 1 gram of calcium per day, or even more for women, may prevent leg cramps at night. Supplemental doses of 50 to 100 milligrams of magnesium may also be helpful, and some people find that taking vitamin E also prevents leg cramps.