The presence of sinus bradycardia is due to cardiac glycoside toxicity, which can be treated with atropine. When cardiac glycoside poisoning is detected, it is necessary to stop continuing to take cardiac glycosides, and it is recommended to go to a hospital immediately for diagnosis and oxygen therapy. In case of conduction block or chronic arrhythmia, i.e. sinus bradycardia, intravenous atropine can be administered. At this moment isoproterenol may cause sinus arrhythmia and is not necessary to install a temporary pacemaker. The presence of a one-time atrioventricular block or a solitary preterm contraction will disappear after discontinuation of the drug. For patients with tachyarrhythmias, potassium-depleting diuretics such as phenytoin sodium or lidocaine can be used if the blood potassium concentration is high. Low concentrations use intravenous potassium supplements. Patients should not use drugs indiscriminately to avoid unnecessary situations or adverse consequences.