WEDNESDAY, July 6 (HealthDay News) -- The heart failure drug Natrecor (nesiritide) is ineffective and linked to increased rates of potentially dangerous low blood pressure, a new study finds.

The intravenous drug was approved in 2001 to help heart failure patients breathe more easily when they were struggling with severe shortness of breath. But the drug had no significant effect on breathing difficulties or other disease-related problems and may also result in low blood pressure, according to the researchers.

The report was published in the July 7 issue of the New England Journal of Medicine.

The study "doesn't show any use for nesiritide, that's for sure," said Dr. Eric J. Topol, professor of translational genomics at the Scripps Research Institute in La Jolla, Calif., and author of an accompanying journal editorial.

Topol noted nesiritide isn't used much, because it is considered no better than some other less expensive drugs. According to Topol, who was not involved in the study, nesiritide can cost $500 to $700 per infusion. Other drugs such as Lasix (furosemide),and nitroglycerin given intravenously cost substantially less and have proven efficacy, he said.

However, Topol's real concerns are much broader. "It shouldn't take this long to find out the truth about a drug," he said. "There should be a drive to get as much information about a drug as early as possible and not have a lost decade, as we saw here."

One of the study authors noted that the research documented the potential risks and benefits of the drug in people with heart failure who have severe trouble breathing -- a condition called dyspnea -- because their disease is worsening.

"This trial demonstrated that nesiritide did not cause an increase in the rate of death or worsening of renal function and that prior concerns regarding the safety of nesiritide were unfounded," said study co-author Dr. Gregg C. Fonarow, a professor of cardiology at the University of California, Los Angeles.

"However, there was only a small non-significant effect on reducing death, rehospitalization and improving dyspnea with nesiritide use for acute decompensated [deteriorating] heart failure in this study," he said. "These results better inform clinicians regarding the potential risks and benefits of nesiritide in treating [such] patients."

After it was approved by the U.S. Food and Drug Administration in 2001, concerns were raised that nesiritide may increase the risk of worsening renal function and mortality, Fonarow noted.

For the study, Fonarow and colleagues randomly assigned 7,141 hospitalized heart failure patients to nesiritide or a placebo along with standard care. The drug or placebo were given from 24 up to 168 hours.

The researchers looked for changes in difficulty breathing at six and at 24 hours after treatment began. In addition, they also looked at the number of people rehospitalized for heart failure within a month.

The researchers found 44.5 percent of the patients receiving nesiritide said their breathing improved after six hours, as did 42.1 percent of those receiving placebo. After a day, 68.2 percent of those receiving nesiritide reported improved breathing, as did 66.1 percent of those on placebo.

However, these differences were not significant, the researchers noted.

In addition, the rates of rehospitalization within 30 days were also not significant -- 9.4 percent for those who had received nesiritide and 10.1 percent for those who received placebo, they added.

There was also no significant difference in the number of deaths or declining kidney function among patients in either group, the investigators found.

Heart failure that deteriorates and causes life-threatening difficulty breathing "is a leading cause of hospitalization worldwide and results in substantial morbidity, mortality and health-care expenditures," Fonarow said.

"The clinical syndrome of [this type of] heart failure is characterized by the development of shortness of breath associated with increased ventricular filling pressures and the accumulation of fluid in the lungs," Fonarow explained.

Nesiritide had previously been shown to reduce lung filling pressures and reduce dyspnea in patients with acute decompensated heart failure, he added.

But, "nesiritide was not associated with an increase or a decrease in the rate of death and rehospitalization and had a small, non-significant effect on dyspnea when used in combination with other therapies," the study authors wrote.

"[Nesiritide] was not associated with a worsening of renal function, but it was associated with an increase in rates of hypotension (low blood pressure). On the basis of these results, nesiritide cannot be recommended for routine use in the broad population of patients with acute heart failure," they concluded.

The study was funded by Scios, a subsidiary of Johnson & Johnson that makes nesiritide.

For his part, Topol worried that there is simply not enough data on the effectiveness of many drugs on the market, such as the cardiovascular drug Zetia (ezetimibe). "It will be over 10 years before we learn the truth about Zetia," he predicted.

Since 2008, the FDA has been investigating claims that Zetia increases the risk of cancer and plaque build-up in the carotid arteries, and when combined with a cholesterol-lowering drug and sold as Vytorin, it does not reduce the risk of cardiovascular events in people with narrowed carotid arteries.

"For new drugs, we don't have an adequate plan to have enough data," Topol said. "We need a rebooting of the whole process so doctors and patients can be comfortable," he said. "It's also an example of profound waste. Billions of dollars were spent on nesiritide when we could have just used Laxis or intravenous nitroglycerin, which costs pennies a dose."

Topol doesn't think nesiritide will be taken off the market, because it "doesn't hurt anyone. But just because it doesn't harm people doesn't mean it should be on the market," he said.

More information

For more information on heart failure, visit the American Heart Association.