Quinine and leg cramps

I thank Katzberg and Breiner for their letter.1 I do not believe that the use of quinine for muscle cramps should be banned, and I concur with the conclusion of the systematic review that Katzberg coauthored: “quinine derivatives for the treatment of muscle cramps should be avoided for routine treatment.” Quinine derivatives should only be prescribed to patients who have been informed of the potentially serious adverse effects and “when cramps are very disabling, no other agents relieve symptoms, and there is careful monitoring of side effects.”2

Our intent was to voice caution about the indiscriminate use of quinine for idiopathic muscle cramps in older patients, not to limit its use for patients with conditions such as amyotrophic lateral sclerosis, who were excluded from the study by Garrison and colleagues.3