QUICK STUDY : A weekly digest of new research on major health topics

chronic obstructive pulmonary disease

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With severe symptoms, not all inhalers act the same.

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· THE QUESTION Two commonly used inhaled drugs have been shown to reduce the wheezing and breathing difficulties that accompany chronic obstructive pulmonary disease (COPD). When symptoms of this progressive lung condition become more severe, do the inhalers still yield comparable results?

· THIS STUDY combined data from 22 studies involving 15,276 people with COPD. In some of the studies, participants had been randomly assigned to use an anticholinergic bronchodilator or a placebo; in other studies, they had used a beta-agonist bronchodilator or a placebo. Beta-agonists used in the studies were albuterol (Proventil, Ventolin, Volmax), metaproterenol (Alupent), formoterol (Foradil) and salmeterol (Serevent, Advair); anticholinergics used were ipratropium (Atrovent) and tiotropium (Spiriva). People who took anticholinergics were 33 percent less likely than those who took placebos to have severe symptoms requiring hospitalization; the hospitalization rate for people who took beta-agonists did not differ from that of the placebo group. Anticholinergics reduced the risk of death by 73 percent vs. placebo (two deaths among 4,036 people, compared with 12 deaths among 3,845 people), whereas beta-agonists more than doubled the risk of death from COPD (21 deaths among 1,320 people vs. eight deaths among 1,084 people).

· WHO MAY BE AFFECTED BY THESE FINDINGS? People with COPD, estimated to number 24 million in the United States. Smoking is a key cause of the disease, but air pollution, respiratory infections and asthma also may contribute.

· CAVEATS All studies of beta-agonists allowed people in the placebo groups to use the drug as needed, thus creating a comparison of regular use vs. as-needed use rather than the standard comparison of treatment vs. no treatment. The authors suggested that the increase in respiratory deaths among beta-agonist users may have been due in part to increased cardiovascular problems, something they were not always able to determine. They also theorized that beta-agonists may keep COPD symptoms in check but not control worsening of the underlying disease.

· FIND THIS STUDY Online issue of the Journal of General Internal Medicine; abstract available at http://www.blackwell-synergy.com/loi/jgi (click "Online early issue" and search for "COPD").

· LEARN MORE ABOUT COPD at http://www.cdc.gov/nceh and http://familydoctor.org .