Severe Overdose of Calcium Channel Blocker and Successful Management: A Literature Review and Case Report

Background: Calcium channel blocker (CCB) toxicity is one of the most lethal and common drug overdoses encountered in the emergency department (ED). The toxicity of these drugs results from blockade of L-type calcium channels in smooth cells, myocardial cells, and beta cells of the pancreas. Severe toxicity can result in bradycardia, hypotension, hyperglycemia, metabolic acidosis, shock, cardiac arrest and death. According to the American Association of Poison Control Centers’ National Poison Data System’s annual report in 2015, cardiovascular medications were the fourth most common adult poisoning exposure and second most common cause of adult poisoning fatality in the USA. CCBs are responsible for a substantial portion of the mortality associated with cardiovascular medication overdose cases. Understanding the emergent management of CCB toxicity is essential. Treatment of patients with CCB overdose remains challenging especially in those with refractory hypotension and end organ dysfunction. Case Presentation: A 45-year-old male with massive amlodipine overdose presented to ED with syncope and severe hypotension. Intensive medical therapy (fluid resuscitation, inotropes, calcium gluconate, and hyperinsulinemia euglycemia therapy [HIET]) was initiated in the ED and continued in the Intensive Care Unit (ICU), and resulted in the patient’s total recovery, without any major complications. Fortunately, ECMO implantation (extracorporeal membrane oxygenation) was not required in this patient. Conclusion: Urgent administration of fluids, calcium, vasopressors, and HIET therapy seem to be the most well validated initial approaches to CCBs overdose treatment. Our successful management strategy should serve as a good learning experience as well as a recommendation for managing such patients.