Safety of budesonide/formoterol maintenance and reliever therapy in asthma trials

The safety of long-acting beta(2)-agonists (LABAs) in asthma is debated. This study examined the safety of the inhaled corticosteroid (ICS)/LABA combination budesonide/formoterol dry powder inhaler used as maintenance and reliever therapy versus combination treatments based on guideline recommendations.

Safety data from six double-blind, randomised clinical trials (RCTs) in asthma where budesonide/formoterol was used as maintenance and reliever therapy for at least 6 months were reviewed (N=14 346). All-cause mortality and asthma-related serious adverse events (SAEs) (co-primary endpoints), overall and cardiac SAEs, and discontinuations due to adverse events (DAEs) were assessed. Estimated Mantel-Haenszel (MH) relative risks (RR) with this regimen versus comparators were calculated.

There was no increase in all-cause mortality with budesonide/formoterol maintenance and reliever therapy (four deaths [0.07%] versus nine [0.10%]; pooled MH RR 0.70, 95% confidence interval [CI] 0.21-2.30). Asthma-related SAEs were reduced with budesonide/formoterol maintenance and reliever therapy: 41 (0.73%) versus 121 (1.38%); pooled MH RR 0.59, 95% CI 0.42-0.85. All-cause and asthma-related DAEs were also reduced with budesonide/formoterol maintenance and reliever therapy: pooled MH RR 0.60 (95% CI 0.46-0.79) and 0.43 (0.28-0.68), respectively. Overall and cardiac-related SAEs were comparable between treatment groups: pooled MH RR 0.96 (95% CI 0.82-1.14) and 1.26 (0.72-2.22), respectively.

Budesonide/formoterol dry powder inhaler maintenance and reliever therapy was well tolerated in RCTs versus fixed-dose alternatives and not associated with increased risk of death or cardiac-related SAEs and DAEs, and asthma-related SAEs and DAEs were significantly reduced. Given the limitations of RCTs, particularly exclusion of patients with co-morbidities, ongoing surveillance is appropriate.