"Despite hundreds of millions of doses administered in the treatment of malaria, there have been no reports of sudden unexplained death associated with quinine, chloroquine or amodiaquine, although each drug causes QT/QTcinterval prolongation. Unfortunately, there are relatively few prospective studies of the electrocardiographic effects of these drugs."
Link to paper: https://www.who.int/malaria/mpac/mpac-mar2017-erg-cardiotoxi...
Link to Chris Martenson's video where I first heard about the 2017 paper: https://www.youtube.com/watch?v=rN_YpFhdii4
Chris Martenson is doing an awesome job staying on top of the science in an apolitical manner.