Long-Term Plavix Risks Do Not Include Increased Mortality, Cancer: FDA

Long-term use of the blood thinner Plavix does not appear to increase or decrease the risk of death or cancer, according to a review by federal drug regulators. 

In a drug safety communication issued on November 6, the FDA announced the results of a year-long review of the potential Plavix risks, following a drug trial known as the Dual Antiplatelet Therapy (DAPT) trial.

The clinical trial looked at the use of Plavix alone, Plavix combined with aspirin, and aspirin alone. The agency also reviewed a number of other long-term Plavix studies to determine whether the popular blood thinner may increase the risk of death among certain patients.

According to the findings, there was no significant difference in all-cause mortality, cancer, or the risk of dying of cancer between the different combinations of possible Plavix and aspirin use. The FDA communication indicates that the agency is continuing to work with Bristol-Myers Squibb and Sanofi-Aventis, the manufacturers, to update the drug’s label.

Plavix (clopidrogrel) is a blockbuster medication that has been used by millions of people in the United States and is commonly prescribed to prevent blood platelets from sticking together and forming clots. There are between 2.5 million and 3 million Plavix prescriptions handed out each month in the U.S.

The review followed a November 2014 Plavix safety warning by the FDA, after researchers who conducted DAPT found that Plavix use after the placement of a stent could increase the risk of death. The FDA then decided to review those results and compare them with other clinical trials.

DAPT was done on the behest of the FDA, involving nearly 10,000 patients who had taken aspirin along with drugs belonging to a class of antiplatelet blood thinners called thienopyridines for a year after receiving heart stents to battle heart congestion. The class includes Plavix, Effient and Ticlid.

After a year on the drugs, all participants in the study were told to continue taking the drugs for another 18 months, but some were given the real thing and others were given a placebo.

Researchers found that taking the drugs had a significant benefit on preventing stent thrombosis, and major adverse cardiovascular and cerebrovascular events; in some case cutting the risks in half. However, the researchers also found that about 2% of the patients who kept taking the drugs for a total of 30 months died, compared to only 1.5% of those taking a placebo. Prolonged use of the drugs also significantly increased the bleeding risks.

“We performed meta-analyses of other long-term clinical trials to assess the effects of clopidogrel on death rates from all causes. The results indicate that long-term (12 months or longer) dual antiplatelet therapy with clopidogrel and aspirin do not appear to change the overall risk of death when compared to short-term (6 months or less) clopidogrel and aspirin, or aspirin alone,” the drug safety communication states. “Also, there was no apparent increase in the risks of cancer-related deaths or cancer-related adverse events with long-term treatment.”

Plavix Health Risks

In recent years, some concerns have emerged about the potential side effects of Plavix and whether many of these prescriptions may have been unnecessary due to genetic resistance to the medication.

In August 2009, researchers from the University of Maryland identified a gene variant found in about one-third of the population that may signal a reduced effectiveness of Plavix. People with the CYP2C19 variant have reduced functioning of a liver enzyme that is supposed to convert Plavix from its inactive form to its active form, potentially making Plavix ineffective at reducing the risk of blood clots.

Unnecessary use of Plavix may expose individuals to an increased risk of gastrointestinal bleeding, severe ulcers, a rare blood disorder known as thrombotic thrombocytopenic pupura (TTP) and other injuries.

Bristol-Myers Squibb and Sanofi-Aventis currently face hundreds of Plavix lawsuits filed on behalf of individuals who suffered severe injuries after using the medication, alleging that the drug makers have placed their desire for profits before the safety of consumers by aggressively marketing the medication while failing to adequately warn consumers or the medical community about the health risks associated with the medication.

Since 2013, all federal Plavix cases have been centralized before U.S. District Judge Freda L. Wolfson in the District of New Jersey for coordinated handling during pretrial proceedings.