The Cardiotoxicity of Drugs and Poisons

Abstract

Cardiotoxicity is manifested by conduction abnormalities, arrhythmias and depression of myocardial contractility but, despite the attention it has attracted, it tends to be uncommon. Potential cardiotoxins vary widely from venoms and inorganic salts to drugs in common use. Tricyclic antidepressants comprise the single most important group of drugs since they are frequently taken in overdosage but newer antidepressants such as maprotiline and older drugs including phenothiazines (particularly thioridazine and mesoridazine) and chloral hydrate, although less commonly encountered in overdosage, occasionally cause serious cardiotoxicity. Of the non-psychotropic drugs, beta-adrenoceptor blockers, bronchodilators of the theophylline type and narcotic analgesics (particularly dextropropoxyphene) are the most important. Acute poisoning with cardiac glycosides would be expected to cause serious cardiac problems but does so less readily than therapeutic overdosage and is uncommon in most countries.