Beta-2 adrenergic agonists: focus on safety and benefits versus risks.

The use of beta(2)-adrenergic receptor agonists, or beta agonists, and their potential for an increased risk of asthma-related death were identified in the 1960's, and appears to have been related to the marketing of specific preparations of short-acting beta agonists (SABA) that are no longer in use today. Subsequent studies have reported a potential for life-threatening or fatal adverse events with the use of long-acting beta agonist (LABA) therapy, but this conclusion must be tempered by the suboptimal design of the studies which form the foundation for these conclusions. Multiple prospective clinical trials and meta-analyses have demonstrated that the combination of a LABA and an ICS confers proven clinical benefits which appear greater than the rare risk for serious or life-threatening adverse events, although all of these studies have inadequate power to be definitive.