FRIDAY, July 9 (HealthDay News) -- In response to continued reports of serious side effects in patients using quinine sulfate (Qualaquin) off-label for the treatment or prevention of nocturnal leg cramps, the U.S. Food and Drug Administration has approved a Risk Evaluation and Mitigation Strategy (REMS) to educate practitioners and patients about the potential for serious side effects associated with such unapproved uses.
Between April 2005 and Oct. 1, 2008, 38 U.S. cases of serious side effects associated with the use of quinine, the active drug in Qualaquin, were submitted to the FDA's Adverse Event Reporting System. The FDA has approved Qualaquin only for the treatment of uncomplicated malaria caused by the parasite Plasmodium falciparum; however, the majority of the drug's use in the U.S. is for the treatment or prevention of nocturnal leg cramps.
The product labeling states that the risks associated with such use of Qualaquin outweigh any potential benefits, due to the absence of evidence of its effectiveness for the treatment or prevention of nocturnal leg cramps. According to the FDA, the use of quinine sulfate may result in serious adverse events, including hematological reactions, which could cause permanent kidney damage, hospitalizations, and death. The REMS requires that patients be given a Medication Guide and that the manufacturer issue a letter to practitioners warning of the risk of serious and life-threatening hematological side effects. Qualaquin is marketed by AR Scientific in Philadelphia.
According to a recent FDA safety alert, "health care professionals should discuss with patients the warning signs of thrombocytopenia, such as easy bruising, severe nose bleeds, blood in the urine or stool, bleeding gums, and the appearance of unusual purple, brown, or red spots on the skin. Patients are encouraged to read the Medication Guide given to them at the pharmacy before starting Qualaquin and each time they get a refill."
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