Intravenous salbutamol: too much of a good thing?

OBJECTIVE: To review the evidence for the use of intravenous salbutamol, its systemic effects and the potential complications that may occur in patients with severe asthma. DATA SOURCES: A review of articles reported on intravenous salbutamol in patients with acute asthma. SUMMARY OF REVIEW: Intravenous salbutamol is recommended in the treatment of severe asthma when there is failure to respond to nebulised beta2-agonists. To date, however, there are no published trials that establish the efficacy or safety of the combination of inhaled salbutamol and a continuous intravenous salbutamol infusion over inhaled salbutamol alone for treatment of severe acute asthma. beta2-agonists have numerous systemic actions that may adversely affect patients with severe respiratory compromise. The most important of these is the potential for beta2-agonists to cause a lactic acidosis, which, by increasing respiratory demands, could precipitate respiratory failure.
CONCLUSIONS: Systemic salbutamol has metabolic effects that may worsen respiratory function in asthma and should not be given by intravenous infusion to asthma patients outside of clinical trials. For patients who fail to respond to inhaled beta2-agonists, ipratropium and systemic steroids, consideration should be given to other therapies such as non-invasive ventilation rather than increasing the dose of a drug that may paradoxically worsen respiratory function.