Efficacy of high-dose inhaled salbutamol for the treatment of
gastro-intestinal anaphylaxis.
Abstract
Background: Abdominal pain is a frequent symptom of IgE-mediated food
allergy with limited therapeutic options. Visceral smooth muscle cell
relaxation can be induced by activation of the beta-adrenergic
receptors. Objective: To evaluate the efficacy of inhaled salbutamol
empirically used to relieve abdominal pain caused by IgE-mediated
allergic reactions at one center. Methods: All double-blind
placebo-controlled food challenges to peanut performed at CHU
Sainte-Justine between 2016 and 2020 were reviewed to identify patients
that presented abdominal pain as part of their reaction. The primary
outcome measure was the delay between the initiation of therapy and
improvement of abdominal pain. It was compared between patients that had
received inhaled salbutamol as part of their treatment and those that
did not. Linear regression was performed to control for potential
confounders. Results: During the study period, 174 positive DBPCFCs were
performed, including 116 for peanut allergy. Of these, 77 presented
abdominal pain and 49 met the criteria for inclusion in the study.
Patients that received salbutamol improved significantly faster (median
14 minutes; range 5-66) than those that did not (61 minutes range 5-194)
(p<0.0001). In the linear regression, only the administration
of salbutamol and emesis were found to independently accelerate the
recovery of abdominal pain, each reducing the time to improvement by an
average of 61 ±10 minutes (p<0.0005) and 44 ±13 minutes
(p<0.0005), respectively. Conclusion: This retrospective study
provides low-quality evidence of a large effect for salbutamol in the
treatment of gastro-intestinal anaphylaxis. Further investigation in
randomized controlled trials would be warranted.