However efficient drugs may be for treating one condition, it is no longer a secret that they can have harmful effects on other parts of our body. This is also the case of inhaler drugs, one of the most commonly prescribed treatments for chronic obstructive pulmonary disease (COPD). According to a study published in the September 24 issue of the Journal of the American Medical Association, these drugs appear to increase the risk of heart attacks and even death.

COPD is often caused by smoking and is the fourth-leading cause of death in the United States, affecting more than 24 million people and killing more than 100,000 each year. The disease is characterized by emphysema and chronic bronchitis, which obstructs airflow to the lungs. There is no cure for this deadly disease and the current drugs do not slow its progression.

The drugs under scrutiny are tiotropium, sold as Spiriva Handihaler by Boehringer Ingelheim Pharmaceuticals, Inc., and Pfizer and ipratropium, available generically and also sold by Boehringer under the brand name Atrovent.

Spiriva was approved in 2004 while Atrovent in 1998 and they both are used to relax muscles and open lung airways. Eight million patients worldwide have used the Spiriva since its approval.

Dr. Sonal Singh, assistant professor of internal medicine at Wake Forest University Baptist Medical Center in Winston-Salem, N.C. and colleagues conducted a meta-analysis of available studies on inhaled anticholinergic drugs that had been used for the treatment of COPD for at least 30 days. There were 17 studies involving almost 15,000 patients. The studies followed the patients for six weeks to five years.

The researchers found a 58 percent increased risk of cardiovascular death, heart attack or stroke in participants receiving inhaled anticholinergics.

“We found a 58 percent increased risk of cardiac death, heart attack or stroke” in people using these inhalers. “In absolute terms, what it means is that if you were to use these drugs for a year, your absolute risk of developing an additional cardiac death would be one in 40,” Dr. Singh said.

Overall, the use of Spiriva and Atrovent drugs increased the risk of a heart attack by 53 percent, cardiovascular death by 80 percent and stroke by 46 percent. This is not new, considering the fact that earlier in March the US Food and Drug Administration said Spiriva may raise the risk of stroke, citing a pooled analysis of 13,500 patients. The researchers couldn’t tell for sure what exactly increased the risk of heart attack in the drugs’ composition, but they believe damaging proteins involved in inflammation are involved in both COPD and heart disease.

Leaving aside this analysis, a Veterans Affairs study published last week linked Atrovent with an increased risk for heart-related deaths in men.

On the other hand, Boehringer and Pfizer released a statement saying that their analysis of 30 studies involving 19,545 patients found no increased risk of heart attack, stroke or death from any cause among the chronic lung-disease patients taking Spiriva.

“We strongly disagree with the conclusion reached by Singh et al. We have disclosed to regulatory authorities worldwide this important information, which is part of a very robust analysis of all our double-blind, placebo-controlled, parallel group trials with a duration of at least 4 weeks. Our analysis, which includes data from the four-year UPLIFT trial, supports the safety profile of Spiriva. Patients and physicians can be confident that Spiriva is a safe and effective medication,” Dr. Andreas Barner, vice chairman of the board of managing directors at Boehringer Ingelheim, said in the statement.