Salmeterol for asthma may cause serious events

NEW YORK (Reuters Health) - Patients with chronic asthma who use the salmeterol on a daily basis are at increased risk for serious adverse events, researchers conclude in the latest issue of The Cochrane Library.

The findings, which stem from a review of 32 clinical trials involving 62,630 patients, also suggest that the use of inhaled corticosteroids with salmeterol may help reduce the adverse effects.

"We found that the biggest increase in risk was seen in people with asthma who were not taking inhaled corticosteroids; however, there is no guarantee that inhaled corticosteroids abolish the risk altogether," lead researcher Dr. Christopher Cates, from Community Health Sciences at St. George's, London, said in a statement.

The studies in the review, which lasted at least 12 weeks, were all clinical trials in which participants were randomly assigned to regular salmeterol or placebo or salbutamol. Of the participants, 2380 were children. Salmeterol is a long-acting beta2-adrenergic receptor agonist that comes as a dry powder and is administered with a special inhaler. It is also sold under the trade name Serevent.

Although the mortality from any cause was higher with salmeterol than with placebo, the difference was not statistically significant, the report indicates. However, salmeterol did increase the risk of non-fatal serious events.

The researchers calculate that one extra serious event arose over 28 weeks for every 188 patients who used salmeterol on a daily basis.

Due to a lack of evidence, the researchers were unable to determine if regular salmeterol use is more or less risky in children compared with adults.

Using data from two large surveillance studies, the researchers found that regular salmeterol use increased the risk of asthma-related mortality in patients not using inhaled steroids.

Patients whose asthma is not adequately controlled by moderate doses of inhaled corticosteroids, the addition of salmeterol can relieve symptoms, "but this may be at the expense of an increased risk of serious adverse events and asthma-related mortality; risks which are not clearly abolished by inhaled corticosteroid," the authors conclude.

SOURCE: Cochrane Database System Review 2008.