FDA Approves New Type of Anti-Clotting Drug

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THURSDAY, May 8, 2014 (HealthDay News) -- The U.S. Food and Drug Administration on Thursday approved a new type of anti-clotting drug for high-risk heart patients.

Sold as Zontivity (vorapaxar), the medication is designed to lower the chances of heart attack, stroke and cardiovascular death, the agency said in a news release. It also lowers the need for procedures to restore blood flow to the heart or to blocked arteries in the legs.

"In patients who have had a heart attack or who have peripheral arterial disease [clogged arteries in the legs], this drug will lower the risk of heart attack, stroke and cardiovascular death," Dr. Ellis Unger, director of the Office of Drug Evaluation I in the FDA's Center for Drug Evaluation and Research, said in the news release. "In the study that supported the drug's approval, Zontivity lowered this risk from 9.5 percent to 7.9 percent over a three-year period."

One heart expert welcomed the drug's approval.

"Patients with previous heart attacks are at increased risk of future heart attack, stroke or death despite the use of currently available anti-clotting agents," explained Dr. Sripal Bangalore, associate professor of cardiology at NYU Langone Medical Center, New York City. "The approval of vorapaxar is a welcome decision as it fills an unmet need and can reduce the risk of the above events further."

FDA officials stressed, however, that Zontivity can't be taken by people who have suffered a stroke, a transient ischemic attack (TIA) ("mini-stroke"), or bleeding in the head, because the risk of bleeding in the head is too great.

The trial the approval was based on included over 25,000 people. When Zontivity was added to other anti-clotting drugs (generally aspirin and Plavix), the rate of heart attack, stroke, cardiovascular death and urgent procedures to improve blood flow to the heart were reduced when compared to an inactive placebo pill, the agency said.

Zontivity belongs to a new class of medications called protease-activated receptor-1 (PAR-1) antagonists.

According to the FDA, patients using Zontivity may bruise or bleed more easily and they should report any long-term or excessive bleeding , or any blood in urine or stool, to their doctor.

Like other drugs meant to prevent blood clots from forming, Zontivity boosts the risk of life-threatening bleeding, the FDA said. The drug's label includes a warning about this risk.

Bangalore said that the bleeding hazard is, "of concern, especially when patients are on aspirin, Plavix and vorapaxar or when newer more potent anti-clotting agents such as prasugrel or ticagrelor is used."

Another expert agreed. "Increased bleeding has been our major concern once vorapaxar is approved for clinical use and hence [the drug] should be used with caution" in certain heart patients, said Dr. Samin Sharma, director of clinical and interventional cardiology at The Mount Sinai Hospital in New York City.

Zontivity is made by Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., of Whitehouse Station, N.J.

More information

The U.S. National Library of Medicine has more about blood clots.