Review question

We reviewed the evidence for the benefit of long-acting inhaled bronchodilators (treatment which opens up the airways often called “relievers”) in people with cystic fibrosis.

Background

Cystic fibrosis affects many systems in the body, in particular how well the lungs work. There is a build-up of thickened, sticky mucus which makes breathing more difficult and makes people with cystic fibrosis more likely to get infections in their lungs. Short- and long-acting bronchodilators are prescribed for most people with cystic fibrosis to widen the airways and improve symptoms. This review partly replaces an earlier review of both short-acting and long-acting inhaled bronchodilators.

Search date

The evidence is current to: 10 October 2017.

Trial characteristics

We included four trials in our review, with a total of 1082 people whose ages ranged from five months to 70 years. The trials included in the review looked at the effects of two different types of long-acting inhaled bronchodilator (beta-2 agonists e.g. salmeterol, and muscarinic antagonists e.g. tiotropium). The trials lasted between 28 days and 12 weeks.

Key results

The small trial of beta-2 agonists compared to placebo (no active medication) reported some improvement in lung function (forced expiratory volume at one second (FEV₁)) after treatment, but did not provide data we could analyse. They did not report on any side effects.

Only one of the three trials comparing tiotropium to a placebo reported on FEV₁ (measured in litres) and found little difference between treatment and placebo. Two of these trials reported on quality of life, but there was not enough evidence to comment on whether this improved or not. Three trials noted side effects, some of which were seen after treatment with tiotropium, but these symptoms were also seen in the group of people who were given placebo. Future trials would improve our knowledge if they measure side effects and quality of life in a more meaningful way.

Quality of the evidence

Only 16 people took part in the trial of the beta-2 agonist which only lasted for 28 days, which makes the results less reliable. The trials of muscarinic antagonists included 1066 people and the trials appeared to be well run. We don’t think any design factors will have influenced the results in a negative way.

None of the trials ran for more than 12 weeks which makes it difficult to comment on the effects over a longer time period.