Heartburn meds may increase heart attack risk
© Ohmega1982/iStockphoto
While the study results need to be confirmed, commentators say the research provides another reason to reduce unnecessary use of the drugs --called proton pump inhibitors (PPIs) -- which are both prescribed and sold over the counter in Australia.
The drugs include the active ingredients omeprazole, esomeprazole, pantoprazole, rabeprazole, lansoprazole, which all work by reducing the amount of stomach acid produced.
"These drugs may not be as safe as we think," says senior author Dr Nicholas Leeper, an assistant professor of vascular surgery and of cardiovascular medicine at Stanford University.
The new research, published today in the journal , relied on mining data from millions of electronic medical records in the United States.
"The risk is small," says lead author Dr Nigam Shah also from Stanford, whose team developed the data mining method used in the study.
"If 4357 people take proton pump inhibitors for two weeks, this will mean one additional heart attack."
But, he says, given how widely used the drugs are, this could result in many additional heart attacks
"Even if it's a tiny elevation of risk at the individual level, at a population level it adds up to pretty large numbers."
The market for PPIs is worth $13 billion worldwide, say the researchers.
According to NPS MedicineWise, PPIs are one of the most widely used medicines in Australia, dispensed over 19 million times and contributing to around $350 million to the PBS expenditure in 2013-14.
Electronic medical records
Shah, Leeper and colleagues analysed data from the electronic medical records of over 30 million people in the US. They identified around 250,000 people who had acid reflux and were able to compare the number of heart attacks in those who took PPIs with those who didn't.
The researchers then combined these findings with an ongoing study that was following 1500 patients, some of whom were taking PPIs.
"All things considered those who took the proton pump inhibiter drugs had about a 20 per cent higher rate at getting heart attack than those on other acid reflux drugs," says Shah.
"We found this association in people who are under 55 who are not at risk of a heart attack just because of their age."
The researchers say their study has limitations. For example, it is possible that some of the people prescribed PPIs actually had angina, and had been wrongly diagnosed as having reflux.
But, they say the suggestion that PPIs actually increase heart attack risk is supported by a previous study they carried out that found PPIs damages blood vessels.
"That basically provides a mechanism by which these drugs could be associated with heart attack," says Shah.
Ideally, the researchers say the link needs to be confirmed in a large, prospective, randomised trial comparing the effect of PPIs and another class of reflux drug, called H2 blockers.
But they estimate any trial would need to have about 4000 subjects to pick up the small risk.
"It would be so prohibitively expensive," says Shah.
Unnecessary use
Dr Katie Ellard, secretary of the Gastroenterological Society of Australia, says the findings needs confirmation, but are another reason to avoid unnecessary use of PPIs.
"They're pretty safe but the trouble with them is they're so widely used," says Ellard.
She says the risk increased identified by Shah, Leeper and colleagues is not "screamingly great" but it still may be important.
"I want people to realise it's not just like taking an antacid," she says.
There has been recent concern expressed by the gastroenterologists world-wide, about the overuse of PPIs, as well as by the RACGP and NPS MedicineWise in Australia.
"The reason for that is it's costly, lots of people don't need to be on them, and there are some potential but not terribly clear risks associated with them," says Ellard.
Apart from common side effects such as headaches, nausea, vomiting and diarrhoea, PPI use has also been associated with serious, though rare side effects such as bone fractures, pneumonia, gut infections, inflammation of the kidneys, or certain vitamin and mineral deficiencies, according to NPS MedicineWise.
Ellard says before recommending PPIs, doctors should be encouraging people to do things like reduce weight, coffee intake and fatty foods first.
"I say to a lot of my patients if you can lose five kilos you won't need to take the medication," she says.
Australia's drug regulator, the Therapeutic Goods Administration is aware of the new research.
"The TGA will review this information to ascertain what, if any, action is required in the Australian context," says a TGA spokesperson.
0 reacties:
Post a Comment