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Atrovent raised risk, while Spiriva might have the opposite effect, two separate studies found
Two separate studies on two different COPD drugs found that the drugs have opposite effects in terms of risk of developing heart problems. The findings of a recent study show that ipratropium bromide (Atrovent), a drug commonly used in treating patients with chronic obstructive pulmonary disease (COPD) may increase the chances of heart attack and heart failure, whereas in a separate study, researchers found that another COPD drug triatropium (Spiriva) may well cut the odds of heart problems and death.
The two aforementioned inhaled medications are the most widely prescribed everyday treatments for patients with COPD, a respiratory disease considered as the fourth-largest killer in the United States. The two studies appear in the January issue of the journal Chest.
"The short-acting form [Atrovent] seems to increase cardiovascular risk, while the long-acting form [Spiriva] seems to decrease it," according to Dr. Norman H. Edelman, chief medical officer of the American Lung Association. He said though that it is necessary to draw attention to the fact "that the difference is an indirect inference."
Edelman added that to provide proof beyond the realms of scientific doubt that the two types of antichilinergic drugs vary in this way and in others, "there would have to be a head-to-head comparison," a study which, he said, has no likelihood of being conducted.
For the first study, Todd A. Lee, from the Hines VA Hospital in Illinois, and fellow researchers, gathered data on 82,717 American veterans with COPD. Forty-four percent of these patients were on Atrovent medication at some point during the course of the study.
The researchers monitored the patients until they (the patients) developed a cardiovascular episode, died or until the end of the study in September 2004. During the follow-up period, 6,234 patients experienced a cardiovascular event: 44 percent had heart failure, 28 percent suffered heart attacks or pain in the chest, and 28 percent had irregular heartbeats, the researchers said.
Moreover, Lee and colleagues found that during the first six months of using Atrovent, patients were at a higher risk of experiencing these cardiovascular events, albeit for those who used the drug for a period of more than six months without having an episode, the odds of suffering a heart attack or heart failure did not increase.
In conclusion, the researchers mentioned that these findings are in harmony with issues raised in the past regarding the cardiovascular safety of using ipratropium bromide.
According to Boehringer Ingelheim, the pharmaceutical company that manufactures Atrovent, the drug is safe and the most recent findings do not provide evidence that it is linked to a higher risk of heart-related problems like heart failure.
Susan Holz, spokeswoman for the company, said that Atrovent has been extensively used in the U.S. for two decades. She added that the findings discussed in the study "are not consistent with the Boehringer Ingelheim clinical trial and safety database for Atrovent, which do not support evidence of an increased risk for cardiovascular events among patients using Atrovent."
Nevertheless, Dr. Sonal Singh, an assistant professor of internal medicine at Wake Forest University Baptist Medical Center in Winston-Salem, N.C., was not in agreement.
He said that the current research on ipratropium corroborates their past evaluation on the cardiovascular risks linked to anticholinergic drugs with the short-acting form of ipratropium.
In the second study, researchers led by Dr. Bartolome Celli, from Caritas-St. Elizabeth's Medical Center in Boston reviewed and analyzed the results of 30 clinical trials involving 19,545 patients, some of whom were treated with Spiriva while others received a placebo.
Celli and colleagues found that compared to patients who were given placebo, those who were taking Spiriva had a lower risk of death. Furthermore, patients on Spiriva therapy showed a lesser number of respiratory events. Sponsoring the study were Boehringer Ingelheim and Pfizer, two gigantic pharmaceutical companies.
"There is a benefit of tiotropium in terms of mortality when data from all of the trials with tiotropium are pooled together," Celli said, adding that this is in on the contrary to a past scare that anticholinergic drugs could be linked to "poor outcomes." He said that in general, tiotropium is "a safe medication that can really help most patients with COPD."
On the other hand, Singh expressed doubts regarding the findings of the study. He said that a considerably higher risk of death and cardiovascular events "has been reported with tiotropium Respimat inhaler in several year-long trials."
According to Singh, "the concomitant use of short-acting inhaled anticholinergics, the incomplete reporting of nonfatal cardiovascular events such as heart attack and mortality in one trial, and the fact that none of these trials were designed to measure cardiovascular risk" is indicative of the fact that the cardiovascular safety of tiotropium is still not clear and entails a thorough investigation by independent researchers.
A progressive, devastating pulmonary disease that is usually caused by smoking, COPD has no known cure to date. Among the symptoms of this disease are difficulty breathing, over-secretion of mucus, oxidative stress and airway inflammatory reaction.
By preventing the air passages from narrowing, anticholinergic inhalants alleviate breathing difficulty experienced by patients with COPD.
The hazards associated with the use of these drugs are still not clear, said Dr. Neil Schachter, a professor of pulmonary medicine at Mount Sinai Medical Center in New York City.
He further said that he is not going make changes in any of his "prescribing habits" at this time. At present, Schachter prescribes Atrovent less frequently than Spiriva.
"Spiriva is certainly a very useful drug," Schachter said. He said that based on his personal experience, there are fairly few side effects associated with the drug. "It is generally well-tolerated, and patients seem to have a good response to it," he added.
In spite of this, he sees no reason not to give Atrovent to some patients.
For patients with severe cases of COPD, Schachter’s prescribes a combination therapy using three drugs composed of Spiriva in addition to a long-acting beta-agonist and a steroid.
He said that a lot of these patients are "desperate." Nevertheless, "you have to be cautious and do the best for the patient you have," Schachter added.
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