On this episode, I discuss the pharmacology surrounding QTc prolongation and drug interactions. I discuss which medications are more likely to cause QTc prolongation and which patient populations we should be more concerned about. Antiarrhythmics are a common class of medication that can exacerbate QTc prolongation when used with other interacting medications. 500 ms is a common value utilized to help identify patients at risk for QTc prolongation and ultimately torsades de pointes.