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have varied degrees of effect on vasodilation, myocardial contractility, and
sinoatrial (SA)-atrioventricular (AV) node function.
Clinical Considerations. Both BBs and CCBs may present with fulminant
cardiovascular and neurologic findings after a large overdose. Typical
presentations of both agents include marked bradycardia and hypotension;
particularly with the CCBs, common additional findings are those of abnormal
AV node conduction, with AV block or accelerated junctional rhythm. However,
it is important to note that overdoses of dihydropyridine CCBs (amlodipine,
nifedipine, etc.) may present with initial hypotension and reflex tachycardia. The
CNS may also be affected, with coma and/or convulsions that occur in either
category of overdoses, though more commonly seen with BBs as compared to
CCBs. Metabolic disturbances include hypoglycemia with BBs and
hyperglycemia and metabolic acidosis with CCBs. Bronchospasm may further
complicate BB toxicity in patients with underlying reactive airway disease.
Management of significant ingestions begins with consideration of aggressive
gastric decontamination for both types of agents. Administer activated charcoal to
patients presenting soon after ingestion if there are no contraindications.
Sustained-release preparations may cause prolonged effects, and whole bowel
irrigation may be considered in this context. Bradycardia and hypotension may
improve with standard treatment such as atropine, fluid boluses, and direct-acting
vasopressors such as norepinephrine; however, many cases prove resistant to
these measures.
Additional therapy includes calcium infusion, which may be beneficial in both
CCB and BB ingestions, with the recommended adult initial dose being 10 mL of
10% calcium chloride or 30 mL of 10% calcium gluconate, which may be
repeated two or three times as necessary (e.g., an initial pediatric dose of
approximately 0.2 mL/kg calcium chloride or 0.6 mL/kg of calcium gluconate).
Serum calcium and ionized calcium should be monitored. Glucagon increases
intracellular cyclic adenosine monophosphate (cAMP) by a mechanism
independent of β-receptors and has been used with success to improve heart rate
and blood pressure in overdoses of BB agents. The usual adult dosing regimen is

3 to 5 mg by IV bolus, which may be repeated to a total dose of 10 mg, followed
by infusion at 2 to 5 mg/hr. Such dosing translates to 50 to 150 μg/kg boluses and
similar amounts per hour for pediatric patients. Emesis is a potential side effect of
glucagon administration.
For hemodynamically significant overdose of a CCB, hyperinsulinemia–
euglycemia therapy is recommended; this therapy should be guided by a clinician