RT Book, Section A1 Darracq, Michael A. A2 Olson, Kent R. A2 Anderson, Ilene B. A2 Benowitz, Neal L. A2 Blanc, Paul D. A2 Clark, Richard F. A2 Kearney, Thomas E. A2 Kim-Katz, Susan Y. A2 Wu, Alan H. B. SR Print(0) ID 1179992453 T1 QUININE T2 Poisoning & Drug Overdose, 7e YR 2018 FD 2018 PB McGraw-Hill Education PP New York, NY SN 9780071839792 LK accessmedicine.mhmedical.com/content.aspx?aid=1179992453 RD 2024/04/19 AB Quinine is an optical isomer of quinidine, a class Ia sodium channel blocking antidysrhythmic drug, with which it shares similar pharmacologic effects. Quinine is the primary alkaloid found in the bark of the cinchona tree and was once widely used for the treatment of malaria and is still occasionally used for chloroquine-resistant cases. A 2006 FDA advisory warned against the use of quinine in the treatment of nocturnal muscle cramps. Quinine is found in tonic water and has been used to cut street heroin. It has also been used as an abortifacient.