Nashville helps pass new drug

Wednesday, July 13, 2005 at 1:00am

The U.S. Food and Drug Administration (FDA) recently approved the drug BiDil for the treatment of heart disease, specifically heart failure, in black patients. Nashville was heavily involved with the successful testing of the drug, the first to target disease in a particular race.

Meharry Medical College, Saint Thomas Hospital, Baptist Hospital, Centennial Medical Center and Vanderbilt University Medical Center - part of 170 institutions participating across the country - were all involved in conducting the specialized clinical study.

In an earlier, non-race specific study, it was determined that BiDil was much more effective for blacks with certain heart problems than any other racial group. The decision was then made to focus tests on blacks.

"BiDil proved to be very effective," said Dr. Theodore Addai, cardiology department chairman and physician in charge of the study at Meharry. "The 43 percent reduction in death rates and a 39 percent decrease in hospitalization is the highest experienced by any group."

The positive results are very significant to the black community because they experience a higher incidence of heart disease than the general population, according to Addai.

Heart failure, also called end-stage cardiovascular disease, affects about 750,000 black people.

Patients experiencing this disease have a number of symptoms including fatigue, swelling of legs, awareness of heart rate that is irregular, difficulty in sleeping and shortness of breath. The longer-term result is heart failure and eventually death.

More than 50 percent of patients with the disease die within five years of diagnosis.

"The crux of the problem for the [black] patients is the neurotransmitters that produce a fight-or-flight response," said Dr. Mark Aaron, medical director of heart transplants at Saint Thomas Hospital. "The [patient's] body is in a continuous state of fight-or-flight."

As a result of the condition, a patient's body and heart suffer negatively. BiDil's benefit is that it diminishes the response, Aaron said.

The medication is a combination of two other drugs, neither approved for heart failure, according to the FDA. The drugs are hydralazine and isosorbide dinitrate.

As an anti-hypertensive agent, hydralazine relaxes the arteries and decreases the strain on the heart. The anti-anginal agent, isosorbide dinitrate, relaxes the veins as well as the arteries.

Common side effects of BiDil are headaches and dizziness.

The drug is just becoming available and is manufactured by NitroMed of Lexington, Mass.

"The recommended dosage for BiDil is two tablets three times a day, or 180 tablets for a one-month supply," said David DiPersio, a pharmacist board certified in cardiology at Vanderbilt University Medical Center.

A patient without insurance would have to spend about $5,000 for a one-year supply of the medication, said DiPersio.

He said that the two drugs that comprise BiDil could be substituted and purchased generically.

A dose equivalent to two tablets of BiDil could be devised by taking two 20 mg tablets of isosorbide dinitrate with one 50 mg and one 25 mg hydralazine tablet, DiPersio suggested.

The annualized cost for the generic version would be between $500 and $600, DiPersio said.

NitroMed said it is working on a system that would allow anyone needing BiDil to have affordable access.

Most patients taking BiDil were also taking ace inhibitors and beta-blocker medications. The non-black population responded better to the other drugs without having to take BiDil.

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