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Do people with asthma have fewer serious adverse events when taking formoterol and inhaled corticosteroids or salmeterol and inhaled corticosteroids?

Cates CJ, Lasserson TJ
Published Online: 
December 7, 2011

Asthma is a condition that affects the airways – the small tubes that carry air in and out of the lungs. When a person with asthma comes into contact with an asthma trigger, their airways become irritated and the muscles around the walls of the airways tighten so that the airways become narrower (bronchoconstriction) and the lining of the airways becomes inflamed and starts to swell. Sometimes, sticky mucus or phlegm builds up, which can further narrow the airways. These reactions cause the airways to become narrower and irritated - making it difficult to breathe and leading to coughing, wheezing, shortness of breath and tightness in the chest. People with asthma are generally advised to take inhaled steroids to combat the underlying inflammation, but if asthma is still not controlled, current clinical guidelines for people with asthma recommend the introduction of an additional medication to help. A common strategy in these situations is to use a long-acting beta-agonists: formoterol or salmeterol. A long-acting beta-agonist is an inhaled drug which opens the airways (bronchodilator) making it easier to breath.

We know from previous Cochrane reviews that there is a small increase in serious adverse events (such as very severe asthma attacks as well as other life-threatening events) when either of regular formoterol and regular salmeterol are compared with placebo treatment in patients who are not also taking inhaled steroids. This review sought information from trials that compared the two treatments (i.e. when people taking salmeterol with an inhaled corticosteroid were compared directly with people taking formoterol and an inhaled corticosteroid) to see if we could determine which drug was the safest.

We found 10 trials on 6769 adults and adolescents, but we did not find any trials on children. We found no significant difference between the treatments, but serious adverse events were too rare to be confident that the risks are the same for both treatments. There are no trials in children; we therefore could not draw any conclusions for children and so more trials are needed.

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