"The U.S. Food and Drug Administration (FDA) continues to educate patients and health providers about safety risks associated with using Quinine (which does not alleviate RLS in any way) to prevent or treat nocturnal leg cramps. While Quinine is approved for use in malaria in certain cases, it has not been adequately studied, is not considered safe treatment for nocturnal leg cramps, and is "off label"( non FDA approved) for that use. Quinine is asssociated with-
Thrombocytopenia(low blood platelet count)
Hypersensitivity reactions, and
QT prolongation (an increase of the electrical activation signal that triggers heartbeat.)"
This is why Quinine is no longer in any over the counter meds in the US, plus is never used, or should NEVER be used for RLS OR nocturnal leg cramps (two different things) at all any more. It is only approved for certain cases of malaria. This is universal and non one should be using Quinine unless you have malaria. Period.