ECG changes in pure impramine overdose as function of plasma level.

ECG changes occur with therapeutic doses of tricyclic antidepressants and cardiovascular conduction alteration is the lethal effect in overdoses on these drugs. These ECG changes depend on the plasma level and metabolism of the particular antidepressant. Information about the relative toxicity and metabolism characteristics can be obtained by studying overdoses if the attempt simply involves one tricyclic and no other drug ingestion. Such a case report involving a known quantity of imipramine is presented. The early toxic signs leading to cardiac arrest and the recovery from coma are discussed. The ECG along with corresponding plasma levels of imipramine and its metabolite desmethylimipramine are given as a function of time after ingestion. The relative toxicity of these metabolites and the use of anticholinesterase in the acute management is considered.