Glucagon-Airway connection

Case: 44 years old male with a past medical history of hypertension (HTN) but stable on extended-release metoprolol, is brought to the Emergency Department (ED) after developing a severe anaphylactic reaction at a local restaurant. Paramedics administered two doses of intramuscular (IM) epinephrine, but there was little to no relief. Intravenous fluid (IVF) resuscitation started in the field. The ED physician administered Glucagon before administering the third dose of 'epi'. The patient developed severe vomiting and aspiration and required intubation.

Discussion: Rapid IV administration of glucagon may induce severe vomiting and may cause life-threatening aspiration and respiratory failure, particularly if trained staff or a controlled environment is not available. Glucagon should be administered with a slow IV push over 5 minutes, followed by an infusion of 5 to 15 mcg/minute until symptoms are resolved. (Pediatric dosing is different.)

Conventionally, literature has described that patients on beta-blockers, and more so, those who are also taking them in combination with angiotensin-converting enzyme inhibitors, develop more severe anaphylactic reactions, but some recent data failed to sustain that claim. Said that the clinician should stay ready in these patients with all arsenals in hand, as anaphylactic shock does not provide any luxury of time! 

Glucagon provides inotropic and chronotropic effects that are not mediated through beta receptors.

#allergy

#hemodynamics

References:

1. Nassiri M, Babina M, Dölle S, et al. Ramipril and metoprolol intake aggravate human and murine anaphylaxis: evidence for direct mast cell priming. J Allergy Clin Immunol 2015; 135:491.

2. White JL, Greger KC, Lee S, et al. Patients Taking β-Blockers Do Not Require Increased Doses of Epinephrine for Anaphylaxis. J Allergy Clin Immunol Pract 2018; 6:1553.

3. Thomas M, Crawford I. Best evidence topic report. Glucagon infusion in refractory anaphylactic shock in patients on beta-blockers. Emerg Med J 2005; 22:272.

4. Miyashiro D, Abud EM, Cook KA, White AA. Managing anaphylaxis in patients on β-blockers: Case insights and practical considerations. Ann Allergy Asthma Immunol. 2025 Jul 7:S1081-1206(25)00335-7. doi: 10.1016/j.anai.2025.06.031. Epub ahead of print. PMID: 40633724.