By Steve Mitchell, MS
WebMD Washington Correspondent
Reviewed by Gary D. Vogin, MD
Aug. 13, 2001 (Washington) -- The FDA approved the first new treatment for acute heart failure in 14 years on Monday, and it appears to be safer than current therapies for the condition.
Called Natrecor, the drug is a synthetic version of a human hormone called natriuretic peptide, which dilates veins and arteries. Clinical trials show that it works faster than nitroglycerin to improve dyspnea.
Natrecor will be at hospitals by the end of the week.
About 5 million Americans have heart failure and approximately 1 million of these patients experience acute episodes of severe shortness of breath requiring a hospital for treatment.
Natrecor, which is manufactured by Scios Inc., is intended for these latter patients. The drug is given intravenously for one to three days at a hospital, Scios' vice president of medical affairs Darla Horton, MD, tells WebMD.
Previously, the FDA had rejected the drug because of concerns that it may cause hypotension.
So Scios went back to the drawing board and conducted one of the largest-ever heart failure studies and "demonstrated to our satisfaction and the advisory committee's" that the drug was effective with a low risk of hypotension, Douglas Throckmorton, MD, tells WebMD. Throckmorton is a deputy director for the FDA.
Natrecor caused some hypotension, but no more so than nitroglycerin, Throckmorton says. The key was that the new trial used a lower dose and a slower rate of infusion of the drug, he says.
But the agency wanted the risk emphasized on labeling to ensure that doctors carefully monitor blood pressure, because when hypotension occurs with Natrecor it tends to last longer than with nitroglycerin, Throckmorton says.
Uri Elkayam, MD, who is director of the heart failure program at the University of Southern California and was involved in two clinical trials of the drug, doesn't see hypotension as a major concern. As long as the physician is aware of it and monitors for it, "it's not really something that is life-threatening," he tells WebMD.
Natrecor makes patients feel better, but whether it extends their life has yet to be determined, Scios' Horton tells WebMD. But she notes that another class of heart failure treatments called inotropes can actually increase the risk of death. "Natrecor does not do this," she says.
Elkayam agrees. Natrecor is "equally effective" as the inotropes but "substantially safer."
He notes that a head-to-head comparison of the two drug types showed that inotropes caused significant arrhythmias, but Natrecor did not.
Elkayam predicts that this advantage will make Natrecor available "in ERs and anywhere in the hospital" in the future. This is not possible with the inotropes because their risk of arrythmia requires them to be administered in the intensive care unit where the patient can be treated quickly if a problem develops.
Natrecor is also safer than nitroglycerin -- it is "more effective and has fewer side effects," Elkayam says.
Another advantage is that Natrecor is easier for physicians to manage than nitroglycerin. Patients first receive an initial dose of Natrecor followed by a continuous infusion of the drug, and the "effect is quite predictable," Elkayam says. With nitroglycerin, it is difficult to know the correct effective dose and when to stop administering the drug.