Imipramine Poisoning
Quang X. Nghiem MD1
Randy C. Randel MD
Thomas L. Leach MD
1 Associate Professor, Department of Pediatrics (Cardiology), The University of Texas Medical Branch, Galveston
The incidence of imipramine poisoning in adults and children is increasing. Toxic effects include an anticholinergic syndrome in the early phase and direct cardiotoxicity that produces abnormalities in rhythm, conduction, and depression of contractility in later phases. In fatal cases, the cardiotoxicity is the most common cause of death. Electrocardiographic changes are so characteristic of imipramine poisoning that the diagnosis can be made or at least suspected on the basis of electrocardiographic alteration. This is illustrated by the case report. Treatment includes induced emesis and/or gastric lavage to remove unabsorbed drug. Diazepam followed by phenobarbital is used to control seizures. Physostigmine is a good agent for treatment of the anticholinergic syndrome, including supraventricular hyperexcitability. Lidocaine is useful for ventricular hyperexcitability. As shown in the case presentation, epinephrine can be effective in reversing the most advanced manifestation of cardiac toxicity, cardiogenic shock.
