structural:summarization, structural:reformatting
Medical

As of 2006, quinine is no longer recommended by the World Health Organization (WHO) as a first-line treatment for malaria, because there are other substances that are equally effective with fewer side effects. They recommend that it be used only when artemisinins are not available. Quinine is also used to treat lupus and arthritis.

Quinine was frequently prescribed as an off-label treatment for leg cramps at night, but this has become less common since 2010 due to a warning from the US Food and Drug Administration (FDA) that such practice is associated with life-threatening side effects. Quinine can also act as a competitive inhibitor of monoamine oxidase (MAO), an enzyme that removes neurotransmitters from the brain. As an MAO inhibitor, it has potential to serve as a treatment for individuals with psychological disorders, similar to antidepressants that inhibit MAO.