FDA Adds New Warning to Plavix Label
Plavix is prescribed to heart disease patients to prevent dangerous blood clots, which can cause heart attack, stroke and death. Plavix was initially approved by the FDA in 1997 and has been linked with serious gastrointestinal problems including gastric and duodenal ulcers and gastrointestinal bleeding.
On March 12, 2010, the FDA announced plans to add its strongest warning to the label of Plavix after reports that some patients cannot process the blockbuster blood thinner, according to a recent Associated Press news reports.
The FDA said in a statement that a number of patients with a genetic variation cannot metabolize the drug, putting them at increased risk for heart attack and stroke. Patients can determine if they don’t respond to Plavix by taking a genetic test. The FDA suggests non-responders use other blood thinners, such as aspirin.
The FDA previously added similar language to Plavix’s label, but the new warning appears within a black box, the FDA’s most severe safety warning.
In order to work effectively, Plavix must be broken down by a particular liver enzyme. But FDA says 2 to 14% of people in the United States have low levels of the enzyme, preventing them from successfully processing Plavix. The likelihood of being a non-responder varies by race, according to the FDA.
The new label notes that using a higher dose of Plavix can increase blood thinning in non-responsive patients, though that use has not been cleared by the FDA.
Plavix is marketed by Sanofi-Aventis and Bristol-Myers Quibb and was the world’s second best selling drug, generating global sales o $8.6 billion in 2008.
In November, the FDA warned that taking stomach-soothing drugs like Prilosec and Nexium alongside Plavix could cut the blood-thinner’s effect in half. Regulators said the key ingredient in the heartburn medications blocks the same liver enzyme needed to break down Plavix, muting the drug’s full effect.
