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©2013 UpToDate ® Print Email Calcium channel blocker poisoning: Rapid overview To obtain emergent consultation with a medical toxicologist, call the United States Poison Control Network at 1-800-222-1222, or access the World Health Organization's list of international poison centers ( www.who.int/gho/phe/chemical_safety/poisons_centres/en/index.html ). Clinical features Hypotension and bradycardia are prominent Electrocardiogram may show PR prolongation or any bradydysrhythmia Patients with a significant calcium channel blocker (CCB) ingestion can deteriorate rapidly Diagnostic evaluation Assays for CCBs are not routinely available Diagnosis depends on the history and clinical presentation Differential diagnosis for unexplained bradycardia includes toxicity from medications including CCBs, beta-blockers, clonidine, and digoxin Structural cardiac disease and active myocardial ischemia must be excluded Treatment Assess and stabilize airway, breathing, and circulation For patients with severe calcium channel blocker (CCB) poisoning (eg, profound hypotension refractory to crystalloid boluses and atropine), give ALL of the following: calcium salts, glucagon, high dose insulin and dextrose, vasopressor, and lipid emulsion therapy For patients with mild CCB poisoning, give the following treatments in succession based upon patient response (see topic text for details): IV crystalloid, atropine, calcium salts, glucagon, high dose insulin and dextrose, vasopressor, and lipid emulsion therapy Initiate treatment for hypotension and bradycardia, if present: Intravenous crystalloid (hypotension): isotonic saline 500 to 1000 mL boluses Atropine (bradycardia): 1 mg IV; may repeat for 3 total doses Intravenous calcium (hypotension and/or bradycardia) Bolus therapy: Calcium chloride - 10 to 20 mL of 10 percent solution (via central venous access if possible) Calcium gluconate - 30 to 60 mL of 10 percent solution Continuous infusion of 0.5 meq calcium/kg per hour Monitor serum calcium and ECG for evidence of hypercalcemia Glucagon (bradycardia) Bolus therapy: 1-5 mg IV push, may repeat up to 15 mg total Continuous infusion: Determine bolus amount needed to obtain response; give this "response dose" every hour as continuous infusion Vasopressor support (hypotension) Norepinephrine: begin 2 mcg/minute IV, titrate rapidly to systolic blood pressure 100 mmHg Hyperinsulinemia with euglycemia (hypotension) Bolus therapy: Regular insulin 1 Unit/kg IV

Continuous infusion: Determine bolus amount needed to obtain response; give this "response dose" every hour as continuous infusion Vasopressor support (hypotension) Norepinephrine: begin 2 mcg/minute IV, titrate rapidly to systolic blood pressure 100 mmHg Hyperinsulinemia with euglycemia (hypotension) Bolus therapy: Regular insulin 1 Unit/kg IV Dextrose 25-50 grams IV; repeat for hypoglycemia; give potassium for hypokalemia Maintenance infusions: Regular insulin: start infusion at 0.5 Units/kg per hour IV; titrate upwards until hypotension corrected or maximum dose of 2 Units/kg per hour reached Dextrose 0.5 grams/kg per hour; titrate to euglycemia Gastrointestinal decontamination Activated charcoal: 1 gram/kg up to 50 grams Whole bowel irrigation: 2 L/hour by mouth; for extended-release preparations only Consider the following therapies if the above measures fail: Transvenous cardiac pacing Intraaortic balloon pump Cardiopulmonary bypass Extracorporeal membrane oxygenation