Experimental Drug Looks Good for Treating Chest Pain
May 24, 2001 (New York) -- For many of the seven million people who live with the crushing chest pain known as angina, current treatments have proven frustrating to say the least.
In fact, some people may be on two or three drugs and still have chest pain when they perform such basic tasks as vacuuming their living room or taking a walk with their spouse. And for those who undergo invasive procedures such as bypass surgery or balloon angioplasty to open blocked arteries, the pain often returns over time.
But that may all be about to change, according to information presented here at a recent meeting sponsored by the American Medical Association.
Ranolazine, the first of a new class of drugs, may offer angina relief minus the side effects of current therapies, according to Marc D. Thames, MD, chief of the section of cardiology at Temple University Medical School in Philadelphia. The drug is still being studied and is not yet available, but its developer, CV Therapeutics, expects to file for FDA approval in mid-2002.
Angina is a signal that the heart is working beyond its capacity. It occurs when the blood flow to the heart muscle is reduced (often by artery-clogging plaque from heart disease), impairing the delivery of vital oxygen and nutrients to the cells and the removal of waste products.
In some cases, blood flow may be enough for normal needs of the heart, but not enough when the heart's needs increase. Running to catch a bus, for example, could trigger an attack of angina. It may also happen during physical exercise, strong emotions, or extreme temperatures.
Currently doctors use a combination of medicines and surgical procedures to open up narrowed heart arteries. The drugs used to treat angina -- including beta-blockers, calcium-channel blockers, and nitrates -- are usually effective, but have a tremendous amount of side effects. For example, beta-blockers may increase risk of depression, sexual dysfunction, and asthma flare-ups, and they can cause swelling of the ankles and legs.
"We hope that once ranolazine is approved, it will be a new choice for people who can't tolerate beta-blockers or other available therapies", Thames says.
And the benefits from the surgical options are often short-lived. For instance, one-quarter of those who undergo bypass surgery to reopen blocked blood vessels will have recurrent angina within a year, as well 40% of those who have the less invasive balloon dilation of heart arteries, or angioplasty.
Ranolazine works by helping the heart get better gas mileage. When the heart is not getting enough oxygen because its blood flow is diminished, it can't burn its fuel -- in this case, fats and blood sugar -- that it needs for energy. But ranolazine helps the heart burn its fuel more efficiently, reducing its need for more oxygen while still allowing it to do its vital job of pumping blood to the rest of the body.