Stop to marketing quinine for night leg cramps - health risks of prescription quinine - Brief Article

FDA Consumer, July-August, 1995

Less than a year after ordering a halt to the marketing of over-the-counter (OTC) quinine sulfate for night leg cramps based on its serious risks, FDA ordered a stop to the marketing of prescription quinine for this use because even under a doctor's care, its risks outweigh any possible benefits.

In January, FDA sent warning letters to 44 companies stating that it is unlawful to market their quinine sulfate products for night leg cramp relief because FDA has not approved the drug for this use. By the end of March, all major manufacturers and distributors had stopped labeling their products for this use, including Marion Merrell Dow, the manufacturer of the original and best-known quinine drug, Quinamm.

From 1969 through June 1992, FDA received 157 reports of health problems related to quinine use, including 23 that resulted in death. Nonserious problems included temporary sight and hearing disturbances, dizziness, fever, nausea, vomiting, and diarrhea. Serious problems included thrombocytopenia, a destruction of blood platelets that can lead to massive bleeding and sometimes death.

After weighing the benefits and risks of OTC quinine sulfate for night leg cramps, FDA concluded that quinine is not safe and effective for this use because:

* No studies demonstrate that quinine is effective against night leg cramps.

* Night leg cramps are not a threat to life or health.

* Health risks outweigh any small potential benefits.

Based on this finding, the agency published a rule in the Aug. 22, 1994, Federal Register prohibiting OTC marketing of the drug for leg cramps.

FDA also proposed to stop OTC marketing of quinine for another use--to prevent or treat malaria. The public has until July 3 to comment on the proposal, published in the April 19, 1995, Federal Register. The agency based the proposal on its conclusion that physician monitoring is essential to the safe and effective treatment of this serious, potentially life-threatening disease. Written comments may be sent to: FDA Dockets Management Branch (HFA-305), Rockville, MD 20857.