As toxicity is the main issue related to the drugs, computational approaches with quantitative structure–activity relationship (QSAR) models and ML methods are used to identify six types of toxicity as cardiac toxicity outcomes: arrhythmia, cardiac failure, heart block, hERG toxicity, hypertension, and myocardial infarction efficiently and accurately. The gene discussed is KCNH2; the disease is Arrhythmia.