Getting to the heart of asthma: Can "β blockers" be useful to treat asthma?

β₂-adrenoceptor agonists are the mainstay for the acute symptomatic treatment of asthma and provide effective bronchoprotection to a wide range of bronchoconstrictor agents. However, over the past 4 decades there has been a continuing debate concerning whether regular chronic treatment with these drugs may be doing more harm than good. The FDA's recent decision to add black box warnings concerning the regular use of salmeterol- and formoterol-containing compounds, as well as their decision not to recommend agents containing long-acting β₂-adrenoceptor agonists as first-line therapy, seems to confirm the concerns regarding the regular use of the long-acting β₂-adrenoceptor agonists. A similar debate arose in the late 1980s concerning the use of β-adrenoceptor agonists in the treatment of heart failure. In this disease, short-term use of β agonists is associated with increased cardiac index and stroke volume, yet their long-term use is associated with increased morbidity and mortality. Moreover, certain β blockers that are initially detrimental when used short term are now considered beneficial in the treatment of this disease when used chronically. Here, there is a parallel, as β blockers are contraindicated in patients with asthma but the use of β blockers chronically has never been evaluated. This begs the question of whether a similar paradigm shift is applicable in the treatment of asthma and whether under certain circumstances the long-term use of certain β blockers may be useful in the treatment of this disease.