Inhaled Salbutamol Versus Placebo for the Treatment of Acute IgE-Mediated Abdominal Pain From Allergic Food Reactions (INSPIRE Trial): A Double-Blind Randomized Trial.

Abstract

Abdominal pain is a frequent occurrence in IgE-mediated food allergy, for which evidence-based acute treatments remain limited. Salbutamol, a short-acting β₂-adrenergic agonist, may induce relaxation of gastrointestinal smooth muscle. To evaluate the efficacy of inhaled salbutamol versus placebo for the treatment of moderate-to-severe IgE-mediated abdominal pain reactions. This randomized, double-blind, placebo-controlled trial enrolled patients aged 6 years to 55 years or less who developed moderate-to-severe abdominal pain during an oral food challenge or oral immunotherapy dose administration. Participants were randomized (1:1) to receive 800 μg of inhaled salbutamol or placebo. Participants self-reported pain intensity at 1-minute intervals for 30 minutes using the Numerical Rating Scale. The primary outcome was time to patient-perceived adequate analgesia. Twenty-four participants (median age, 11.5 years, 37.5% females) were randomized at a single center. The median time to patient-perceived adequate analgesia was 6.0 minutes in the salbutamol group and was not reached by 30 minutes in the placebo group (hazard ratio, 0.35; 95% CI, 0.12-0.99; P = .034). The median time to complete resolution of abdominal pain was 10.0 minutes with salbutamol and was not reached by 30 minutes in the placebo group (hazard ratio, 0.33; 95% CI, 0.12-0.92; P = .027). The trial was terminated early because of changes in clinical practice resulting in slower-than-expected recruitment. In this prematurely terminated randomized trial, inhaled salbutamol was associated with faster relief from IgE-mediated, food allergy-related abdominal pain compared with placebo. These findings require confirmation in a larger, multicenter study.