Beta Blocker and Calcium Channel Blocker Toxicity

The answer first

Beta blocker (BB) and calcium channel blocker (CCB) poisoning is a potentially lethal toxidrome dominated by bradycardia, hypotension and shock from a combination of negative chronotropy, negative inotropy and peripheral vasodilatation, and it is managed by a sequence that begins with resuscitation, decontamination and escalating antidotal therapy, with high-dose insulin euglycaemic therapy (HIET) as the cornerstone adjunct and venoarterial extracorporeal membrane oxygenation (VA-ECMO) as the salvage bridge for refractory cardiogenic shock. ^{[1] [2]} The answer-first decision at the bedside is to recognise the toxidrome, institute HIET early — before the patient is in extremis — and not to wait for standard chronotropes and vasopressors to fail before escalating to lipid emulsion, pacing and extracorporeal support. ^{[4] [11]}

For the FRACP candidate, this is a high-yield DCE short-case and DWE vignette topic because it tests the integrated physician: cardiorespiratory resuscitation, toxicology, endocrine pharmacology, intensive care retrieval and ethics around self-harm. Lead with the decision (the patient is in calcium-channel-blocker-induced shock, I am starting HIET now and have called the ECMO service), then defend the pharmacology, then name the trap (a "transient responder" after calcium or fluids is not a safe patient). ^{[1] [3]}

References12ShowHide

1. [1]St-Onge M, Anseeuw K, Cantrell FL, et al. Experts Consensus Recommendations for the Management of Calcium Channel Blocker Poisoning in Adults Crit Care Med, 2017.PMID 27749343
2. [2]Lavonas EJ, Akpunonu PD, Arens AM, Babu KM, et al. 2023 American Heart Association Focused Update on the Management of Patients With Cardiac Arrest or Life-Threatening Toxicity Due to Poisoning Circulation, 2023.PMID 37721023
3. [3]Graudins A, Lee HM, Druda D Calcium channel antagonist and beta-blocker overdose: antidotes and adjunct therapies Br J Clin Pharmacol, 2016.PMID 26344579
4. [4]Engebretsen KM, Kaczmarek KM, Morgan J, Holger JS High-dose insulin therapy in beta-blocker and calcium channel-blocker poisoning Clin Toxicol (Phila), 2011.PMID 21563902
5. [5]Krenz JR, Kaakeh Y An Overview of Hyperinsulinemic-Euglycemic Therapy in Calcium Channel Blocker and β-blocker Overdose Pharmacotherapy, 2018.PMID 30141827
6. [6]Rotella JA, Greene SL, Koutsogiannis Z, et al. Treatment for beta-blocker poisoning: a systematic review Clin Toxicol (Phila), 2020.PMID 32310006
7. [7]Routsolias JC, Berg SE, Paloucek FP Does Glucagon Really Work for Beta Blocker Overdose? J Med Toxicol, 2023.PMID 36536191
8. [8]Wong A, Hoffman RS, Walsh SJ, et al. Extracorporeal treatment for calcium channel blocker poisoning: systematic review and recommendations from the EXTRIP workgroup Clin Toxicol (Phila), 2021.PMID 33555964
9. [9]Cole JB, Arens AM Cardiotoxic Medication Poisoning Emerg Med Clin North Am, 2022.PMID 35461630
10. [10]Meamar R, Samsamshariat S, Dorvashi G, Feizi A, et al. Intravenous Lipid Emulsion in Beta-Blocker With or Without Calcium Channel Blocker Toxicity: A Systematic Review of Human Case Reports and Series J Appl Toxicol, 2026.PMID 42365995
11. [11]Mégarbane B High-dose insulin should be used before vasopressors/inotropes in calcium-channel blocker toxicity Br J Clin Pharmacol, 2023.PMID 36604796
12. [12]Finn D, Stevens J, Tolkacz M, et al. Calcium Channel Blocker Overdose: What Role Does Extracorporeal Membrane Oxygenation Have in Support? A Systematic Review of the Literature ASAIO J, 2024.PMID 38165982