Active Ingredient: QUININE
Quinine and Quinidine block inward Na current (INa) and hERG (IKr) channel. They have very different activities and QT prolongation where quinine is about four times less arrythmogenic than quinidine
https://doi.org/10.1016/S1473-3099(07)70187-1, https://academic.oup.com/europace/article/27/8/euaf076/8100306, https://pmc.ncbi.nlm.nih.gov/articles/PMC5023602/, https://www.fda.gov/media/178811/download