Long-term off-label use of quinine, still prescribed to individuals with muscle cramps despite Food and Drug Administration warnings of adverse events, is associated with an increased risk of death. This is according to a study published by JAMA.
Laurence Fardet, MD, PhD, of the Universite Paris Est Creteil, France and colleagues used data from a UK primary care database and included adults who received new quinine salt (sulfate, bisulfate, dihydrochloride) prescriptions for idiopathic (unknown cause) muscular cramps or restless leg syndrome for at least one year from January 1990 to December 2014 at an average dosage of 100 mg/d or more (exposed group).