TUESDAY, Jan. 20, 2004 (HealthDayNews) -- A drug that uses a unique tactic to lessen the workload of the heart can help people with the chronic chest pain of angina when other medications fall short, a new study says.
The drug, ranolazine, prevents heart cells from metabolizing fatty acids, their usual energy source. The cells then get their energy from glucose in a metabolic process that is easier on them. The result is improved exercise capacity and decreased pain.
More than 6 million Americans have chronic angina, which is caused by partial blockage of the coronary arteries. Angina can be relieved by bypass surgery or angioplasty to increase blood flow, but many patients must take drugs to limit the number and severity of angina attacks.
A report in the Jan. 21 issue of the Journal of the American Medical Association on a large-scale study says that adding ranolazine to existing drug regimens brought significant benefits to patients with chronic angina.
The trial was sponsored by CV Therapeutics Inc., the company that developed ranolazine. It included 823 people with chronic angina who were taking nitroglycerin, the basic medication for angina, and other cardiac drugs such as beta blockers or calcium channel blockers.
"We report the first evidence that ranolazine can reduce both angina frequency and nitroglycerin consumption when added to a standard dose of one of three frequently prescribed anti-anginal drugs," the researchers write.
Ranolazine probably will be used in addition to existing drugs when it comes on the market, says study leader Dr. Bernard R. Chaitman, a professor of medicine at Saint Louis University School of Medicine. He is also a paid consultant to CV Therapeutics.
"The drug would be effective in patients who also are on a beta blocker or calcium channel blocker," Chaitman says. How it will be used in clinical practice depends in part on the labeling authorized by the U.S. Food and Drug Administration, he adds.
But, Chaitman says, "I would be comfortable in using it for some patients without another agent." An earlier trial showed it to be effective as a single agent, he says.
For example, ranolazine would be good alternative to a patient who could not take a beta blocker because of a very low heart rate, he says. Beta blockers slow the heart rate even further.
Candidates for ranolazine treatment are those "who have chronic angina that does not respond to the usual kind of therapy," he says. "These are patients with four or five attacks of angina a week."
Even after angioplasty or bypass surgery to improve blood flow and existing drug treatments, about a quarter of all angina patients experience persistent attacks, the journal report notes.
Ranolazine is in the final stages of the process leading to approval by the FDA for its use as an angina treatment. The agency has issued a letter saying the drug appears to be effective in a step that usually leads to approval for general use in medical practice.
"There was a recent advisory meeting in December to discuss the application," says John Bluth, spokesman for CV Therapeutics. "The next step is for us to talk to the FDA and map out a path for potential approval. The company is engaged in a dialogue with the FDA, which has expressed an interest in more data."
More information
A review of current drug treatments for angina can be found at the American Heart Association, while the National Heart, Lung, and Blood Institute has a primer on the disorder.
