FDA Remains Concerned About Plavix Heart Risk with Prilosec

Federal health regulators indicate that they are still concerned about the potential heart risks when Plavix is combined with Prilosec, despite a recent study that suggested the heartburn medication may not reduce the effectiveness of the blood thinner.

The FDA is planning to reiterate a public health advisory that was originally issued last year, warning that warned that Prilosec and other stomach acid reducers may interfere with Plavix, increasing the risk of heart attack, death and other injuries. The agency’s intentions were reported in a recent Wall Street Journal article and the reiterated warning has not yet been released.

Earlier this month a study published in the New England Journal of Medicine that found that side effects of Prilosec and Nexium did not appear to have any clinically significant impact on Plavix. The study contradicted the findings of a number of other studies, which have suggested that the use of the drugs reduces the effectiveness of the anti-clotting drug by about 50%.

The latest study was funded by Cogentus Pharmaceuticals, which is trying to develop a product that combines Plavix with heartburn medication to make it easier on patients’ stomachs.

FDA officials told the Wall Street Journal that Cogent’s study was too small and used a time-release form of Prilosec that is not available to most patients. They said the FDA will reiterate the warning because they are afraid doctors will interpret the new study as meaning that it’s okay to use the Prilosec and Plavix together again.

Last year, the FDA required new warnings about Plavix heart risks when used with Prilosec, Nexium or other heartburn drugs that work by inhibiting the CYP2C19 enzyme. The FDA has said that this latest study could not provide conclusive results due to its small size. 

Plavix (clopidogrel) is a blood thinner that prevents blood platelets from sticking together to form clots. It is prescribed to prevent heart attacks, strokes and blood clotting when drug coated stents are used in patients with arteriosclerosis and in other at-risk patients. It is a blockbuster medication, generating annual sales of over $6 billion for Bristol Myers Squibb Co. and Sanofi-Aventis.

Prilosec (omeprazole) is a proton pump inhibitor used to reduce stomach acid, which is manufactured by AstraZeneca and available as a generic.

Prilosec and other stomach acid drugs are often prescribed along with Plavix to combat upset stomachs caused by gastrointestinal bleeding, a common Plavix side effect. The FDA indicates that Prilosec may actually inhibit the drug metabolizing enzyme in the body that normally would convert Plavix into its active form, which reduces its effectiveness, putting patients at risk of heart attack and stroke.