Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 38-25: Calcium Channel Blockers Overdose + Key Features Download Section PDF Listen +++ ++ All calcium channel blockers can cause arteriolar vasodilation and depression of cardiac contractility after acute overdose Examples of calcium channel blockers Verapamil Diltiazem Nifedipine Nicardipine Amlodipine Felodipine Isradipine Nisoldipine Nimodipine + Clinical Findings Download Section PDF Listen +++ ++ Bradycardia, atrioventricular (AV) nodal block, hypotension, or a combination With severe poisoning, cardiac arrest may occur + Diagnosis Download Section PDF Listen +++ ++ Clinical Junctional bradycardia is common, with even moderate verapamil or diltiazem poisoning + Treatment Download Section PDF Listen +++ ++ Activated charcoal Give 60–100 g mixed in aqueous slurry orally or via gastric tube Do not use for comatose or convulsing patients unless they are endotracheally intubated Perform whole-bowel irrigation as soon as possible if a sustained-release product has been ingested Treat hypotension and bradycardia with calcium chloride intravenously Start with 10%, 10 mL, or calcium gluconate, 20 mL; repeat the dose every 3–5 minutes Maximum dose has not been established Many toxicologists recommend raising the ionized serum calcium level to as much as twice the normal level Calcium is most useful in reversing negative inotropic effects It is less effective for AV nodal blockade and bradycardia High doses of insulin 0.5–1.0 units/kg bolus followed by 0.5–1.0 units/kg/h infusion with sufficient dextrose to maintain euglycemia may be beneficial Infusion of Intralipid 20% lipid emulsion has been reported to improve hemodynamics in animal models and case reports of calcium channel poisoning Methylene blue (1–2 mg/kg) was reported to reverse refractory shock due to profound vasodilation in a patient with amlodipine poisoning