Asthma

What the evidence shows

Short-acting reliever monotherapy is over. In mild asthma, as-needed budesonide-formoterol cut severe exacerbations by roughly two thirds compared with as-needed terbutaline (SYGMA 1) and matched daily inhaled steroid for exacerbation prevention on a quarter of the steroid dose (SYGMA 2). Be honest about the trade: daily inhaled steroid still gives better day-to-day symptom control. The same anti-inflammatory reliever principle extends to patients on separate maintenance therapy, and to salbutamol rather than formoterol (MANDALA).

Adding to inhaled steroid and LABA, a long-acting muscarinic antagonist gives modest bronchodilation and a 21% reduction in severe exacerbations (PrimoTinA-asthma) — cheap, tolerable, and worth trying before a biologic.

Biologics work, and the interesting question is for whom. Tezepelumab acts upstream at TSLP and halved exacerbations regardless of eosinophil count, including in patients below 300 cells per microlitre (NAVIGATOR) — the group anti-IL-5 agents cannot help. Depemokimab achieved comparable exacerbation reduction with just two injections a year (SWIFT), though as with the other anti-IL-5 drugs quality of life did not follow. Benralizumab given at the time of an acute eosinophilic attack beat prednisolone (ABRA), which is a different idea altogether: treating the exacerbation rather than preventing it.

For the patient no biologic will help — the neutrophilic, non-eosinophilic asthmatic — azithromycin remains one of the few options, reducing exacerbations by 41% and improving quality of life (AMAZES). Screen hearing and the QT interval first, as the trial did.