Severe labetalol overdose in an 8-month-old infant

We report a case of a large labetalol overdose in an eight-month-old infant that was being treated for hypertension following surgery for coarctation of the aorta. Labetalol, both alpha and beta adrenergic blocking agent was used for treating postoperative hypertension. By mistake, the patient was given an extremely high dose of labetalol intravenously (17.2 mg·kg⁻¹). Remarkably, the medication error had a surprisingly limited clinical effect on the infant who survived the incident. We discuss the pharmacokinetic, pharmocodynamic and possible explanations for this fortunate turn of events.