What combination of effects is associated with tricyclic antidepressants due to receptor blockade?

• A. Cardiac conduction abnormalities, convulsions, coma
• B. Liver toxicity and jaundice
• C. Weight gain and metabolic syndrome
• D. Hypertension and tachycardia only

Answer: (A)

Tricyclic antidepressants block multiple receptors, and when toxicity occurs, the most concerning and characteristic picture is a mix of central nervous system depression and cardiac electrical disturbance. The cardiac problems come from blockade of fast sodium channels in the heart, which slows conduction and can produce widened QRS complexes and dangerous arrhythmias. In parallel, high drug levels cause central nervous system effects leading to seizures and coma. This combination—cardiac conduction abnormalities plus seizures and coma—is the classic overdose pattern with TCAs, reflecting their broad pharmacologic blockade. The other options describe organ-specific or less characteristic effects (liver toxicity, weight/metabolic effects, or isolated hypertension/tachycardia) that don’t capture the dangerous, systemic overdose syndrome TCAs can produce.