Carvedilol Overdose with Quantitative Confirmation

Abstract: Carvedilol is a non-selective β-adrenoreceptor antagonist that is also an antagonist at the α₁-adrenoreceptor. This unique pharmacological effect may produce a different toxicodynamic profile compared to other β-adrenoreceptor antagonists. Only one previous case of carvedilol overdose has been reported. Here, we report massive carvedilol ingestion confirmed by quantitative analysis. The case report deals with an 84-year-old man who chewed a total of 60 (6.25 mg) tablets and rapidly developed symptoms. Vital signs on presentation were systolic blood pressure 70 mmHg; heart rate 45 beats/min.; respirations 18 breaths/min.; temperature 37°. The electrocardiogram showed a junctional rhythm at 49 beats/min. The patient was treated with normal saline boluses, repeated glucagon boluses (2–3 mg each) and a dopamine infusion. At 14 hr after ingestion, he was weaned off vasopressors and was in a normal sinus rhythm. Quantitative confirmation showed a carvedilol serum concentration of 472 ng/ml (steady-state concentration 8.5 ng/ml during 6.25 mg twice daily dosing). Despite its unique pharmacological properties, the clinical manifestations of carvedilol overdose appear similar to other β-adrenoreceptor antagonists.