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Thursday, April 29, 2010

Another challenge to reported risks of long-acting β2-agonists

The FDA’s position on long-acting β2-agonists has taken another hit, this time in an article reporting results from analysis of a massive database: the UK’s General Practice Research Database.

De Vries et al. (Eur Resp J 2010, published online, doi:10.1183/09031936.00124209) look at SABAs and LABAs prescribed for adults with asthma and associated clinical outcomes of death, asthma death, and hospitalization for status asthmaticus. The authors use a new pattern analysis method to determine absolute hazard rates rather than relative risk, which has the advantage of detecting differential effects independent of changes in exposure to treatment.

Starting with the British Thoracic Society’s guidelines for asthma management, exposure outcomes follow the 5 treatment steps that go from minimal intervention with SABAs to routine use of oral corticosteroids in addition to LABAs and ICS. Hazard rates were highest for the first-step and last-step interventions. These populations are recent starters and heavy, long-term treatment users, respectively. Heterogeneity of asthma medication exposure resulted in substantial variability of risk, but overall, no significant risk increases in all-cause and asthma deaths are associated with LABAs, irrespective of other concomitant therapies.

The finding associated with long-term exposure isn’t entirely surprising, but the high risk for new users is unexpected. De Vries et al. speculate that this effect could derive from excessive use of SABAs when no other treatment is prescribed or treatment of misdiagnosed cardiovascular dyspnoea.

Tell us what you think. Please feel free to post your own comments and/or predictions below. Topics and articles that you think would be of interest in our NBOP section and/or this blog can be sent to the JACI Editorial Office at jaci@njhealth.org.

1 comment:

  1. For more on LABAs and the reaction to the FDA's recommendation, see the AAAAI's resource page for physicians and patients at: http://www.aaaai.org/members/resources/expert_labas.asp

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