A Breakthrough Drug for Pulmonary Hypertension

A pill can prolong lives, reduce need for implanted catheter

FRIDAY, Oct. 5, 2001 (HealthDayNews) -- A new drug is promising both medical -- and perhaps financial -- relief to patients with the rare and potentially fatal condition called pulmonary hypertension.

An estimated 30,000 people in the United States suffer from the condition, a progressive narrowing of the small blood vessels in the lung that often leads to failure of the right side of the heart and death. Until now, the only treatment has been a medication that must be delivered 24 hours a day through an implanted catheter.

The new drug, bosentan, is taken in pill form and is called "a major breakthrough in the field" by the researcher who led one study that led to Food and Drug Administration approval last month. The findings are reported in the Oct. 6 issue of The Lancet.

"There were really striking results which were even somewhat surprising to us," says study leader Dr. Richard Channick, associate clinical professor of medicine at the University of California, San Diego. "This was a pilot study that was supposed to look at drug safety. The results were extremely powerful despite the small number of patients."

Half the 32 patients in the study got bosentan and half got a placebo. After 12 weeks, the bosentan patients had improved heart function, reduced resistance to blood flow in the pulmonary arteries and substantially improved performance in a walking test compared with the placebo patients.

Bosentan acts against a hormone called endothelin, which causes blood vessels to constrict, Channick says.

Lorie Simmons, director of advocacy and awareness for the Pulmonary Hypertension Association, says, "This means that for the first time, patients with pulmonary hypertension will have a new option for treatment, a drug specifically developed for this disease."

The current cost of treatment with 24-hour infusion of Flolan, the only available drug, through an implanted catheter is $120,000 a year, she says. The catheter is attached to a reservoir of the drug worn around the waist.

Simmons says, "Compare that to a pill. I don't know what the cost of Tracleer [the brand name of bosentan] will be, but hopefully it will be a lot less expensive."

Channick says availability of the new drug may lead to more diagnoses of pulmonary hypertension, which is "probably often unrecognized." Symptoms, which include shortness of breath during physical exertion, chest pain, dizziness or fainting spells and swelling of the legs, often are attributed to asthma, emphysema or other conditions, he says.

"The findings and presentation of the patients are fairly subtle, so significant delays in diagnosis and misdiagnosis can occur," he says.

Simmons says pulmonary hypertension often occurs as a complication of another disease, such as lupus erythematosus or scleroderma and often is overlooked in the treatment of those diseases,. "With a pill available, those dermatologists who are looking after scleroderma patients may be aware that they can treat pulmonary hypertension, so we may have greater diagnosis and treatment."

Actelion, Ltd, a Swiss pharmaceutical company, will market bosentan which is expected to be available in the next few months.

What To Do

This drug won't be for everyone. Tests have shown, for example, that it can cause liver problems.

Information about pulmonary hypertension and its treatment is offered by the Pulmonary Hypertension Association, the American Lung Association and the National Heart, Lung and Blood Institute.

SOURCES: Interviews with Richard Channick, M.D., associate clinical professor of medicine, University of California, San Diego, and Lorie Simmons, director of advocacy and public awareness, Pulmonary Hypertension Association, Silver Spring, Md.; Oct. 6, 2001 The Lancet
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