What is one of the most dangerous complications of an untreated drug overdose?

Cardiac arrest is one of the most dangerous complications of an untreated drug overdose due to the profound effects certain drugs can have on the cardiovascular system. Many overdose situations involve substances that depress or alter the heart's rhythm, leading to significant disturbances such as bradycardia, tachycardia, or complete cardiac failure. Opioids, for instance, can significantly slow down the respiratory rate and heart function, resulting in hypoxia and decreased blood circulation, which can culminate in cardiac arrest.

Other complications can arise from an overdose, such as kidney failure from prolonged hypoperfusion and potential seizures caused by certain stimulants or withdrawal effects. While stomach bleeding can occur in cases of specific overdoses, it is not as immediate or life-threatening as the risk of cardiac arrest. Therefore, understanding the critical impact that drug overdoses can have on heart function underscores the importance of rapid and effective intervention in these medical emergencies.