What do systematic reviews say?

Regular salmeterol vs salbutamol

Regular salmeterol showed no clear difference in asthma‐related mortality ‐ adults and adolescents compared with regular salbutamol (moderate certainty).

• Regular treatment with salmeterol for chronic asthma: serious adverse events 2008 · Cochrane Headline outcomes only
  OR 2.36 [0.78, 7.16]
  4 studies · 26463 participants
  Moderate

Regular salmeterol vs placebo

Regular salmeterol leads to higher asthma‐related mortality ‐ adults and adolescents compared with placebo (high certainty).

• Regular treatment with salmeterol for chronic asthma: serious adverse events 2008 · Cochrane Headline outcomes only
  OR 3.49 [1.31, 9.31]
  10 studies · 29128 participants
  High

Intervention not reported

• Inhaled steroids with and without regular salmeterol for asthma: serious adverse events 2018 · Cochrane Headline outcomes only
  no estimate extracted
  41 studies · 27951 participants
  Moderate

Intervention not reported

• Inhaled steroids with and without regular salmeterol for asthma: serious adverse events 2018 · Cochrane Headline outcomes only
  no estimate extracted
  8 studies · 8453 participants
  Moderate