The use of inhalers to deliver the drug tiotropium significantly increased the death rate among people suffering from chronic bronchitis or emphysema, according to a new study.
The results show that those using such an inhaler were 52 percent more likely to die than those using a placebo, the researchers said.
"What we think is going on is that the mist inhaler is delivering a higher concentration of tiotropium than it should be and that may be increasing the risk of death," said study researcher Dr. Sonal Singh, an assistant professor at the Johns Hopkins University School of Medicine.
The new study raises concerns not only about the mist inhaler but also about the drug itself, the researchers said. In the United States and elsewhere, the medication is available in a powdered form and sold under the brand name Spiriva. The drug is commonly used to treat chronic obstructive pulmonary disease (COPD).
Fifty-five other countries now allow tiotropium to also be administered using a mist inhaler.
The Food and Drug Administration has not approved such inhalers for use in the U.S., though U.S. patients are taking part in a large, 17,000-patient study comparing two devices using the same drug.
"I'm worried about the participants assigned to the use of the mist inhaler," Singh said. "They are not fully informed about what could be serious safety issues with the device."
The increased number of deaths linked to the inhaler are primarily from cardiovascular disease, Singh said. Tiotropium belongs to a group of drugs called anticholinergics, which increase the risk of heart rhythm disturbances (arrhythmias), especially among those with existing heart conditions.
The new study was an analysis of five previously conducted studies involving 6,500 people.
The study showed there was one death yearly, above what would statistically be expected, due to the mist inhaler for every 124 patients treated.
COPD is the fourth leading cause of death worldwide, and includes the chronic lung diseases emphysema and bronchitis, which are usually brought on by decades of smoking, the researchers said. Tiotropium is routinely given to COPD patients with symptoms such as shortness of breath, and those with hospitalizations as a result of their breathing problems.
The shortness of breath caused by COPD can be treated with other long-acting bronchodilators, the researchers said. The risk of additional hospitalizations for these chronic lung diseases can be reduced somewhat by other COPD inhalers. Singh said patients should discuss the risks and benefits of COPD treatments with their doctors.
The findings are published today in the British Medical Journal. The research was funded by a grant from the National Center for Research Resources and the National Institutes of Health Roadmap for Medical Research.
Pass it on: The drug in Spiriva may be linked to an increased risk of dying from heart disease.