Use of Quinine for Relief of "Night Cramps" in the Extremities

Painful tonic spasms of muscles in the extremities of middle aged and elderly patients who may show little evidence of serious structural changes of the peripheral blood vessels frequently cause the practicing physician considerable concern. These muscular contractions usually occur while the patient is at rest and are frequently referred to as "night cramps." On the basis of reports of Wolf and Kennedy¹regarding the effect of quinine hydrochloride on skeletal muscles in myotonia congenita and in myotonia atrophica, one of us (H. K. M.) administered quinine sulfate to a woman whose suffering from these "night cramps" in both lower extremities was of such intensity that she was afraid to go to bed. The rapid cessation of symptoms prompted a study in a group of patients both with and without evidence of organic changes in the peripheral arteries. Since March 1939 clinical studies have been conducted in the Vascular