Beta2-agonists: Friend or foe?

This review summarizes the effects of beta2-agonists on asthma severity. There has been a controversy as to whether the regularly scheduled use of beta2-adrenergic agonists increases the risk of adverse outcomes in asthma. A number of epidemiological and clinical studies have found an association between the regularly scheduled use of beta-agonist drugs and increased risk of asthma morbidity and mortality. However, this observation has not been consistent across studies. We discuss here the potential mechanisms to explain the relationship between the use of beta-agonists on a regularly scheduled basis and adverse outcomes of asthma therapy; and we provide a brief review of the effect of genetic diversity at the beta2-adrenergic receptor locus on asthma severity. Overall, the evidence suggests that the beta2-agonists in current use in the United States are generally safe and effective; friends, not foes.