What do systematic reviews say?

Adults: formoterol/ICS vs salmeterol/ICS

Adults: formoterol/ICS showed no clear difference in all‐cause non‐fatal serious adverse events ‐… compared with salmeterol/ICS (moderate certainty).

• Regular treatment with formoterol and an inhaled corticosteroid versus regular treatment with salmeterol and an… 2021 · Cochrane Headline outcomes only
  OR 0.94 [0.43, 2.08]
  6 studies · 1941 participants
  Moderate