Patients Taking β-Blockers Do Not Require Increased Doses of Epinephrine for Anaphylaxis.

BACKGROUND: β-Blocker use has been associated with increased anaphylaxis severity.

OBJECTIVE: We aimed to assess for an association between β-blocker use and requirement for more than 1 dose of epinephrine for anaphylaxis management.

METHODS: We conducted a retrospective observational study of patients seen in our emergency department for anaphylaxis between April 2008 and January 2015. The primary outcome measure was the number of doses of epinephrine. Associations with repeat epinephrine administration (>1 vs ≤1 dose of epinephrine) and associations with any epinephrine administration (>0 vs 0 dose) were evaluated using logistic regression models and summarized as odds ratio (OR) and 95% CIs. The study was powered to detect a 10% or greater difference in need for repeat epinephrine administration between patients who were and were not taking β-blocker medications.

RESULTS: Of 789 patient visits with a documented medication history included in the study, 63 (8%) required more than 1 epinephrine dose and 83 (11%) were on β-blocker therapy. Among patients who required more than 1 epinephrine dose, 8 (13%) were taking a β-blocker, compared with 75 patients (10%) who received 0 or 1 dose of epinephrine (OR, 1.26; 95% CI, 0.58-2.75). Among patients who required at least 1 epinephrine dose, 41 (9%) were taking a β-blocker, compared with 42 patients (12%) who received no epinephrine (OR, 0.73; 95% CI, 0.46-1.14).

CONCLUSIONS: β-Blocker use may not be clinically significant with regard to the need for epinephrine dosing among emergency department patients with anaphylaxis.