The safety of long-acting beta-agonists: more evidence is needed.

There is controversy regarding the possibility that long-acting beta-agonists (LABA) may paradoxically contribute adversely to asthma mortality. While studies and meta-analyses indicate increased risk, epidemiological data indicate a slow fall in asthma mortality since the introduction of LABA. Advocates for LABA propose that mandatory simultaneous use of inhaled corticosteroids satisfactorily reduce any potential risk. In the face of lingering doubts, others propose that LABA should be withdrawn from use. In this pro-con article, Kazani et al. provide the rationale for a modified randomized controlled trial that would define the level of risk more clearly, and provide the basis for a clear judgment to be made. Sears argues that current knowledge about the risks associated with LABA, especially when prescribed as monotherapy, provides sufficient evidence for clinicians and licensing authorities alike, and that the logistics and likely outcomes for a large prospective study are unjustified.