Combined calcium channel blocker and angiotensin-converting enzyme inhibitor overdose

Authors

• Fares Kahal Faculty of Medicine, Syrian Private University, Damascus, Syria
• Natasha Guérard-Poirier Department of Emergency Medicine, McGill University, Montreal, Canada; Department of Emergency Medicine, Jewish General Hospital, Montreal, Canada
• Cheng Ji Department of Pharmacy, McGill University Health Center, Montreal, Canada
• Ashvini Gursahaney Faculty of Medicine, McGill University, Montreal, Canada; Department of Medicine, McGill University Health Centre, Montreal, Canada; Department of Critical Care Medicine, McGill University Health Centre, Montreal, Canada
• Marc Perreault Department of Pharmacy, McGill University Health Center, Montreal, Canada; Faculty of Pharmacy, Université de Montréal, Montreal, Canada
• Ghina Moussa Department of Pharmacy, McGill University Health Center, Montreal, Canada

fareskahal@hotmail.com

Keywords

Abstract

Introduction: Combined overdoses of angiotensin-converting enzyme inhibitors and calcium channel blockers are rare but associated with more severe toxicity than either agent alone.
Case description: A 48-year-old woman presented to the emergency department nine hours after intentionally ingesting 40 tablets of amlodipine (10 mg) and 40 tablets of ramipril (10 mg). On arrival, she was hypotensive and tachycardic. Initial management included fluids, intravenous calcium and insulin bolus followed by high-dose insulin euglycaemic therapy (HIET). Despite escalating vasopressor support, she developed mixed vasoplegic and cardiogenic shock complicated by acute kidney injury, fluid overload, respiratory failure and metabolic acidosis, necessitating intubation and continuous renal replacement therapy. Improvement in haemodynamics was only achieved by day 9. She was transferred from the intensive care unit (ICU) on day 20 with residual weakness from ICU-acquired myopathy and was ultimately discharged after 66 days, with a prolonged hospitalisation attributed to delirium and deconditioning.
Discussion: Severe combined angiotensin-converting enzyme inhibitors (ACEI) and calcium channel blockers (CCB) overdose may cause prolonged, refractory haemodynamic instability requiring extended high-dose insulin euglycaemic therapy (HIET), vasoactive support and fluid administration. Concentrated insulin, dextrose and vasopressor preparations may help mitigate fluid overload. Angiotensin II may be a potential treatment for refractory vasoplegia, although evidence and availability remain limited. Secondary complications can prolong recovery beyond the duration of drug toxicity.
Conclusion: This case highlights the need for individualised, multidisciplinary management, early HIET, vasoactive support and fluid-sparing strategies in severe combined ACEI and CCB overdose.

References