Nicholas J. WhiteSornchai LooareesuwanDavid A. WarrellMahidol UniversityUniversity of OxfordLiverpool School of Tropical Medicine2018-10-122018-10-121983-01-01Journal of Cardiovascular Pharmacology. Vol.5, No.2 (1983), 173-17515334023016024462-s2.0-0020678283https://repository.li.mahidol.ac.th/handle/123456789/30541We recorded electrocardiograms from 31 patients receiving quinine and 14 patients receiving quinidine for the treatment of Plasmodium falciparum malaria. Despite plasma quinine concentrations of up to 20 mg/L, there was no evidence of cardiotoxicity. QT prolongation was considerably greater in the quinidine-treated patients. The mean ratio of change in corrected QT interval to change in plasma concentration (ΔQTc%/ΔCo) was 3.2%·mg-1·L1for quinidine, compared to 0.74%·mg-1·L1for quinine (p < 0.001). T-wave flattening was observed in both groups. Plasma concentrations of quinine cannot be predicted from the EKG, because concentrations within the therapeutic range produced only minor and unpredictable abnormalities. © 1983 Raven Press, New York.Mahidol UniversityMedicinePharmacology, Toxicology and PharmaceuticsArticleSCOPUS10.1097/00005344-198303000-00001