A widely prescribed drug used to treat patients with chronic obstructive pulmonary disease – the fourth leading cause of death in the United States – may damage patients’ hearts, according to a recent study conducted by Northwestern’s Feinberg School of Medicine.
Chronic obstructive pulmonary disease, in most cases, refers to two incurable illnesses: chronic bronchitis and emphysema. Both illnesses are caused by an inflammatory response of the lungs to harmful dust or particles. Over time, the disease leads to an irreparable decline in breathing ability.
The drug in the study, ipratropium, is marketed under the brand names Atrovent and Combivent. Both drugs, called bronchodilators, manage symptoms by inhibiting mucus secretion and airway constriction.
But patients who used the ipratropium-based drugs for their COPD symptoms were 34 percent more likely to die of heart-related problems than those who used alternative medications, the Feinberg study, published Sept. 15, found.
The study was conducted by looking into the causes of death for 145,000 veterans from 1999 to 2003.
Dr. Todd Lee, lead author of the study and research assistant professor at the Institute for Healthcare Studies at Feinberg, said that even though about 12 million Americans have COPD, public knowledge about it is limited.
“COPD really flies underneath the radar screen – it’s not as high-profile of a disease as cancer or heart disease,” Lee said.
Although the study shows a strong correlation between ipratropium use and heart problems, researchers are still studying the actual effects of ipratropium on the cardiovascular system.
“That’s a key question,” Lee said. “If we knew that, the results would be more believable. We need to try to understand the systemic effects of this medication.”
However, bronchodilator medication could induce increased heartbeat which might lead to potential heart ailments, he said. Lee also said the data are not completely conclusive.
“This is just one observational study,” Lee said. “More research will either support or refute what we found.”
Drug companies have a responsibility to look into the safety of their products, Lee said, adding that there are other options for doctors prescribing drugs for COPD patients.
“Ipratropium is not the only choice – other medications are available,” he said. “If I were treating a COPD patient, I’d consider alternative treatments.”
The study, funded by a grant from the U.S. Department of Veterans Affairs Health Services Research and Development, used administrative data from the National Veterans Affairs Database to draw its correlations.
The database has its limitations, said A. Simon Pickard, an associate professor of Pharmacy Practice and Pharmacy Administration at University of Illinois at Chicago who worked with Lee on the study.
“In this study, we did not have access to data on how the patient feels, such as their ability to manage symptoms and their quality of life,” Pickard said. “Risk of mortality is obviously an important factor that guides treatment decision making, but quality of life is also a critical issue to patients with chronic disease.”
Dr. Ravi Kalhan, assistant professor and director of the COPD Program at Feinberg’s Division of Pulmonary & Critical Care, was not involved in the study but said future ipratropium studies need to consider both the risks and benefits of the drug.
“I think the benefits (of ipratropium) outweigh the risks,” Kalhan said.
