In 2010, in response to a prolonged debate over the safety of long-acting beta-agonists (LABAs), the United States Food and Drugs Administration (FDA) issued guidelines for the use of LABAs in asthma,1 and mandated a very large trial examining the safety of LABAs used with concomitant inhaled corticosteroid (ICS).2 Strong voices have called for new safety data,3 4 while others have expressed doubt regarding the need for, and likely outcomes of, new trials.5 6

Controversy regarding safety has surrounded the use of long-acting beta-agonists in asthma virtually since salmeterol (Serevent, GlaxoSmithKline) was introduced into clinical practice in the UK in 1990 (figure 1). Studies showed greater control of asthma with addition of salmeterol to ICS compared with increased doses of ICS7