Everyone's an expert….
HCQ is no different than any other medication; yes it can cause QT prolongation, Torsades and eventually V-fib (lethal arrhythmia) - usually found in long term use or in high doses, or in patient's with other medical conditions that could cause unwanted reactions. These things are called contraindications (relative - risk versus benefit, absolute - risk too high for any benefit) and or precautions. If a thorough history is done, and no absolute contraindications, it can be used safely. Some people refuse to see fact over the "MSM truth".