May 20th, 2013

Similar Cardiovascular Risk Observed with COPD Drugs

A large observational study has found no difference in the increased risk for cardiovascular disease between the two main classes of drugs used in the first-line treatment of chronic obstructive pulmonary disease (COPD). LABAs (long-acting inhaled beta-agonists) and LAMAs (long-acting muscarinic antagonists) have a variety of beneficial effects in COPD patients, but evidence has been building that these agents may produce a small but significant increase in cardiovascular risk.

In a new study published online in JAMA Internal Medicine, Andrea Gershon and colleagues analyzed data from nearly 200,000 elderly COPD patients from Ontario, Canada. Of these, 28% of the group had a cardiovascular event. When compared to matched controls not taking either of the drugs, new users of the two drugs were more likely to experience a cardiovascular event  (odds ratio for LABAs: 1.31, CI 1.12-1.52; OR for LAMAs: 1.14, CI 1.01-1.28). The difference between LABAs and LAMAs was not significant. The elevated risk for both class of drugs was highest in the first few weeks after the start of treatment.

The results, write the authors, “support the need for close monitoring of all patients with COPD who require long-acting bronchodilators regardless of drug class.”

In an accompanying commentary, Prescott Woodruff writes that the study provides an accurate portrait of the real-world use of these drugs. The study, he notes, “captures early ‘sentinel’ events that might otherwise lead to participant exclusion in a clinical trial.” However, the study does not provide information about the relative safety of a newer formulation of one LAMA, the Respimat Soft Mist Inhaler (Boehringer Ingelheim), which delivers a smaller dose of tiotropium in a fine cloud but may result in higher plasma levels. The safety of the Respimat system is now being studied in a large trial. In addition, the Ontario study did not study any difference in effect that might exist between LAMAs and LAMAs when used in combination with inhaled corticosteroids.


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