Quinine for night-time leg cramps no longer recommended

Quinine for nighttime leg cramps? Think again

If you have nocturnal (nighttime) leg cramps, your doctor might prescribe quinine (Qualaquin)-even though the U.S. Food and Drug Administration has approved it for only one purpose: to treat malaria (although doctors can legally prescribe most medications for any type of treatment they deem appropriate).

Leg cramps are uncontrolled muscle contractions that can be so painful they can waken you from sleep. They occur in many adults and are reported more often by women, and especially pregnant women.

Since the 1940s, doctors have been prescribing quinine for leg cramps because there are no other reliable treatments. The practice has continued despite multiple alerts from the FDA about the risks of quinine and its limited effectiveness.

Prescribing remains high despite warnings

The FDA has issued warnings about quinine since 1994 and more recently about its minimal effectiveness in treating leg cramps. In 2006, it banned the sale of all unapproved drugs that contained quinine except the branded drug, Qualaquin, because of the risk of serious side effects or death. Yet in the first six months of 2008, more than 124,000 people in the U.S. received close to 300,000 prescriptions for Qualaquin, according to the FDA. Since the Centers for Disease Control and Prevention reports that only about 1,500 individuals were diagnosed with malaria last year, it appears that quinine is still frequently prescribed off-label.

Indeed, from January 2006 to June 2008, 62 percent of Qualaquin prescriptions were for musculoskeletal symptoms, mainly for nocturnal leg cramps. Of the 38 reports of serious adverse events received by the FDA in roughly the same time period, over half (55 percent) were from people who had taken quinine for leg cramps.