AR Scientific, Inc, the manufacturer of the malaria drug Qualaquin (Quinine), warns that misuse of the drug could result in serious or life-threatening hematologic complications. Quinine is intended to be used as a treatment for malaria. Some physicians have prescribed the drug off-label to treat nocturnal leg cramping.
In a release sent to health care providers across the United States, AR Scientific warns that using Quinine for the treatment or prevention of nocturnal leg cramps may lead to thrombocytopenia and hemolytic-uremic syndrome/thrombotic thrombocytopenic purpura (HUS/TTP). Chronic renal impairment associated with the development of TTP has been reported. The release also states that there is no evidence that Quinine is effective in treating or preventing nocturnal leg cramps.