A new analysis that compares two common inhalers for patients suffering from chronic obstructive pulmonary disease (COPD) finds that one reduces respiratory-related hospitalizations and respiratory deaths, but the other—which is prescribed in the majority of cases—increases respiratory deaths.
The Cornell and Stanford universities’ statistical analysis of 22 trials with 15,276 participants found that common bronchodilators known as anticholinergics (tiotropium, ipratropium) reduced severe respiratory events by 33% and respiratory-related deaths by 73%, compared with a placebo.
However, the same meta-analysis (which combines the results of the numerous studies) found that regularly inhaled beta-agonists (metaproternol, formoterol, salmeterol, albuterol) increased the risk of respiratory death more than twofold, compared with a placebo.
Yet only 5% of all prescriptions for COPD are anticholinergics, with beta-agonists dominating what doctors prescribe, the researchers report.
The study, now online, will be published in an upcoming issue of the Journal of General Internal Medicine.
Previous studies have shown that patients with COPD build up tolerance to beta-agonists’ bronchodilator and bronchoprotective effects after regular treatment compared with the first dose.
While beta-agonists may reduce symptoms through bronchodilation, the researchers believe they also promote bronchial inflammation and sensitivity by reducing bronchial protection without any warning of increased symptoms, which can then lead to a life-threatening response.
In the trials that were analyzed, only two patients out of 4,036 who took anticholinergics died of respiratory causes, while 12 of 3,845 participants in the placebo group died of respiratory ailments. When patients inhaled beta-agonists, there were 21 respiratory deaths out of 1,320 patients and eight respiratory deaths out of 1,084 participants in the placebo group.