Published:December 25, 2022DOI:



      Angiotensin-converting enzyme (ACE) inhibitor overdose is an uncommonly presenting toxicologic emergency. Management is primarily supportive care, but a small body of evidence exists to support naloxone for management of hypotension.

      Case Report

      We present a case of accidental ACE inhibitor overdose. The patient took approximately 300 mg lisinopril over 48 h and presented for evaluation of syncope. He was hypotensive and unresponsive to fluids. We administered naloxone with immediate and sustained resolution in hypotension. The mechanism of action is briefly discussed.
      Why Should an Emergency Medicine Physician Be Aware of This? Naloxone is a rapid, low-risk, low-cost, and effective intervention for hypotension due to ACE inhibitor toxicity. It is supported by basic science research and clinical experience.


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