As-needed budesonide-formoterol was well-tolerated in patients with mild asthma, and no new safety signals were identified.

As-needed budesonide-formoterol had a safety profile similar to that of twice-daily maintenance budesonide but with a lower total exposure to corticosteroid. The safety profile of as-needed budesonide-formoterol was favorable compared with as-needed terbutaline.

Only a very small proportion of patients receiving as-needed budesonide-formoterol required sustained high use of their treatment.