Common Acid Reflux Drugs May Lead To Heart Disease, New Research Suggests
28667 postsback to top
Posted 5 months ago
Research by John P. Cooke, clinical professor and chair of the department of cardiovascular sciences at Houston Methodist Hospital, found that stomach acid-suppressing proton pump inhibitors (brand names Prilosec, Nexium, Prevacid) may cause blood vessels to constrict, reducing blood flow.
Studying both mouse and human tissue cultures, the researchers found that PPIs led to an approximately 25 percent increase in a chemical messenger called ADMA (asymmetric dimethylarginine), considered a cardiovascular risk factor.
ADMA suppresses blood vessels’ ability to produce nitric oxide, a relaxant that protects artery walls. Nitric oxide is so important to cardiovascular health that its discovery was honored with a Nobel Prize in 1998.
In the study, PPIs reduced the ability of mouse blood vessels to relax by an average of more than 30 percent. “We also found the same effect in human blood vessels,” says Cooke. “This is very important because blood vessels need to be able to contract and open up to control blood flow.”
Of course, mouse studies can only take us so far, and may not extend to humans. The researchers call for a large-scale study to determine if PPIs pose a risk to heart health. “Of concern, this adverse mechanism is also likely to extend to the general population using PPIs,” read the study’s conclusions.
Cooke and colleagues have been conducting additional research, not yet published, which he believes will back up the study’s assertions. “There’s going to be more information coming out that will, in my opinion, raise concerns about the long-term effects of proton pump inhibitors and risk of heart damage,” Cooke says.
The research is convincing enough that people who regularly take PPIs should discuss the potential risks with their doctors, Cooke says. It’s likely to be a difficult choice: If you have a family history of GERD, Barrett’s esophagus, and esophageal cancer, then PPIs are probably a good idea. But if you have heart disease risk factors or a family history of heart disease, then you might reconsider using PPIs.
“I’d tell people, if there’s something else they could be taking that would effectively control their symptoms, such as Zantac or Tagamet, maybe that would be better,”says Cooke, who until recently was professor of cardiovascular medicine Stanford University School of Medicine and associate director of the Stanford Cardiovascular Institute before moving his lab to Houston. The published study involved teams from Stanford, Houston Methodist Hospital, and Imperial College London.
“We used several different model systems, including whole human blood vessels, and saw the same effect in each of these situations.” In addition, his team’s research is “consistent with other signals that have been coming from the literature for some time.”
Cooke is referring to previous studies such as this one, published in the Journal of the Canadian Medical Association, and this one, published in 2011 in the British Medical Journal that have linked PPIs with increased risk of heart attack and heart damage in people who’ve already had a prior cardiovascular event. These studies have pointed to the possibility that PPIs are interfering with the action of blood thinners such as aspirin and clopidogrel (brand name Plavix), preventing them from performing their important anti-clotting function.
At the moment, the American Heart Association considers proton pump inhibitors safe. In 2010, the AHA issued a joint statement with the American College of Cardiology and the American College of Gastroenterology reaffirming the safety of PPIs with clopidogrel and other anti-clotting drugs for people considered “at risk for upper GI bleeds.” But the professional groups did not recommend “routine use” of PPIs for patients taking clopidogrel or aspirin.
28667 postsback to top
| Posted 5 months ago
Which Drugs Are Cause for Concern?
The most commonly taken PPI drugs are sold over the counter and by prescription, both as brand names and generics. In addition to Prilosec (AstraZeneca AZN +0.1%), Prevacid (Takeda), and Nexium (AstraZeneca), popular PPI brands include Protonix (Wyeth), Zegerid (Santarus SNTS +2.34%), Aciphex (Eisai /Johnson & Johnson), and new arrival Dexilant (Takeda), and generics include lansoprazole, omeprazole, pantoprazole, esomeprazole, and dexlansoprazole.
Proton pump inhibitors are very big business; in 2009 they passed cholesterol-lowering medications to become the second-largest class of drugs sold in the U.S. with total sales of 13.6 billion, according to IMS Health. Nexium alone brought $6.3 billion in sales to maker AstraZeneca in 2009.