Overdose of Metoprolol Treated with Enoximone

Abstract

To the Editor: Severe poisoning with β-adrenergic–receptor blocking agents, which leads to decreased production of cellular cyclic AMP and impaired release of calcium from the sarcoplasmic reticulum, causes bradycardia and hypotension that can be refractory to treatment with catecholamines, calcium, and glucagon.1 We report on a patient with a life-threatening overdose of metoprolol, whose hemodynamic condition improved dramatically with the administration of enoximone, an inhibitor of phosphodiesterase III. The patient was a 55-year-old woman who intentionally ingested metoprolol in a total dose of 10 g. She was found unconscious about one hour later, with a heart rate of 55 beats . . .