Acute poisoning by drugs with membrane-stabilizing effect

A rare clinical situation characterized by acute, potentially life-threatening toxic effects of drugs acting on voltage-gated sodium or calcium channels, such as tricyclic antidepressants, anticonvulsants, local anesthetics and antiarrhythmics, some beta-blockers, and chloroquine. Clinical manifestations include abnormal ECG findings (intraventricular conduction block with widening of the QRS complex, T wave flattening, prolongation of the QT interval) and variable signs and symptoms depending on the drug, typically involving the cardiovascular and central nervous system, among others.