The bronchodilator effect of intravenous glucagon in asthma exacerbation: a randomized, controlled trial

Glucagon is a rapid-acting smooth muscle relaxant with a short half-life. Previous studies suggested glucagon may have bronchodilator effects. We sought to determine whether intravenous glucagon produces clinically important immediate bronchodilation in emergency department patients with asthma exacerbation.

We conducted a randomized, double-blind, placebo-controlled study at 2 university-affiliated community teaching hospital EDs (annual census 90,000). ED patients 18 to 50 years old with asthma exacerbation and peak expiratory flow rate (PEFR) less than 350 L/min were eligible. Exclusion criteria were need for intubation, chronic obstructive pulmonary disease, diabetes mellitus, insulinoma, pheochromocytoma, pregnancy, lactation, or current oral steroid treatment. Patients were randomly assigned to receive glucagon 0.03 mg/kg or an equivalent volume of saline solution intravenously. At 10 minutes, PEFR was measured and all patients began standardized albuterol therapy. Successful bronchodilation was a PEFR increase of 60 L/min at 10 minutes.

Success occurred in 2 (9.5%) of 21 glucagon-treated patients and 3 (12%) of 25 placebo-treated patients (95% confidence interval [CI] for difference of -2.5% [-20.4% to 15. 4%]). Mean PEFR improvement for glucagon was 2 L/min versus 9 L/min for placebo (95% CI for difference of -7 L/min [-36 L/min to 23 L/min]).

Glucagon alone provided no clinically important immediate bronchodilation in ED patients with asthma exacerbation.