Hypoglycemia-induced hypertension in a diabetic patient on metoprolol

Metoprolol is the only cardioselective (β₁) beta-adrenergic antagonist approved for use in the United States. This agent may be preferable to nonselective β-adrenergic blocking agents in stressful situations in which nonselective β₁ and β₂ blockade would permit unopposed epinephrine induced α-adrenergic vasoconstriction and hypertension. Because insulin-induced hypoglycemia may result in elevated levels of epinephrine, metoprolol has been recommended for use in diabetic hypertensive patients in preference to propranolol. We report a case of severe hypertension induced by hypoglycemia in a diabetic hypertensive patient receiving metoprolol.