[Unfounded objections against the use of salbutamol/ipratropium].

Abstract

In acute bronchospasm due to asthma/COPD exacerbations two bronchodilators are frequently used: ipratropium, an acetylcholine antagonist, and salbutamol, a β2-agonist. The combination ipratropium/salbutamol gives more bronchodilation than ipratropium monotherapy in asthma/COPD exacerbations, but there are concerns about cardiac safety of salbutamol. Salbutamol in regular dosage does not affect heart rate in diverse populations (ED, ICU and children). Only a dosage 5-10x the standard dosage of 2,5 mg leads to a 20-30-beat increase in heart rate. High-dose salbutamol induced a mild increase of QTc interval (±360 to ±390ms) and QTc dispersion (maximum minus minimum QTc; marker for susceptibility to arrhythmia), but not to a clinically relevant extent. Most importantly, literature shows that the incidence of arrhythmia is similar between salbutamol and placebo. Salbutamol did not induce severe arrhythmias, including in arrhythmogenic ICU populations or in patients with severe COPD with cardiac comorbidity. We therefore argue that the current caution exercised with the use ipratropium/salbutamol is unjustified. Treatment should not be withheld in case of tachycardia or underlying heart disease.