Some heartburn drugs linked to increased risk of heart attack

People taking proton-pump inhibitors used to treat heartburn—like AstraZeneca's Nexium, Procter and Gamble's Prilosec and Takeda's Prevacid—were associated with a 16% to 21% increase in the chance of suffering a heart attack, according to research published Wednesday in Plos One.

Stanford University researchers used data-mining techniques to pore over 2.9 million patient records from a Standard Translational Research database known as Stride and Practice Fusion, a free EHR platform.

They looked at patients taking six brands of PPIs: Nexium, Prilosec, Prevacid, Pfizer's Protonix, Eisai's Aciphex and Takeda's Dexilant. They also looked at patients taking H2 blockers, another popular treatment for heartburn, including Zantac, Pepcid, Tagamet and Tazac. Their analysis showed no evidence of increased risk of heart attack in patients taking H2Bs.

Researchers conjecture that proton-pump inhibitors may hinder the the production of nitric oxide from cells that line the inside of the body's circulatory system, including the heart. Past research has found that low levels of nitric oxide are associated with cellular disturbances that can lead to heart failure.

Nexium represents a significant portion of AstraZeneca's revenue—the “purple pill” had sales of $3.6 billion in 2014. AstraZeneca raised its forecast twice last year, citing a lack of competition for the acid-reflux treatment.

Researchers concluded that their findings warrant further investigation and represent a novel way for data-mining to be used to identify drug-safety gaps.