Data from 15 randomised trials show that while long-acting muscarinic antagonists reduced exacerbation risk by a third, there was no significant improvement compared with long-acting beta-agonists.

Long-acting beta-agonists (LABAs), such as salmeterol, are currently the primary add-on therapy for patients with persistent asthma. However, the comparative efficacy of long-acting muscarinic antagonists (LAMAs), such as tiotropium bromide, is less clear.

To explore, researchers carried out a systematic review and meta-analysis of 15 randomised trials comparing a LAMA with placebo or a LABA, as add-on therapy to inhaled corticosteroids (ICS) in 7,122 patients with persistent asthma[1].