Proton pump inhibitors (PPIs) are a widely available class of drug designed to curb excess stomach acid production. They are commonly found in heartburn tablets such as omeprazole and lansoprazole.
The drugs, taken by millions of people in the UK each year, work by blocking the enzyme in the wall of the stomach that produces acid.
Off the back of the new findings, researchers have suggested that the use of PPIs should be restricted.
PPI use has previously been linked to a heightened risk of chronic kidney disease, dementia, C difficile infections and bone fractures in people with brittle bone disease. There is also emerging evidence suggesting that they may boost the risk of tissue damage.
For the new study, published in the BMJ Open, researchers examined data involving more than six million people whose health was tracked for an average of six years - until 2013 or death, whichever came first.
Compared with people who used H2 blockers - a class of medications containing active ingredients which travel to specific receptors on the surface of the stomach cells that release acids - PPI use was associated with a 25% heightened risk of death from all causes. This increased the longer PPIs were taken.
The risk of death was also increased among those who were taking PPIs despite having no appropriate medical indication for their use.
Researchers noted that it’s an observational study, so no firm conclusions can be drawn about cause and effect. They also added that many of the study’s participants were mostly older white US veterans, which could possibly limit the wider applicability of the findings.
Experts wrote in the journal: “Although our results should not deter prescription and use of PPIs where medically indicated, they may be used to encourage and promote pharmacovigilance [monitoring the side-effects of licensed drugs] and [they] emphasise the need to exercise judicious use of PPIs and limit use and duration of therapy to instances where there is a clear medical indication and where benefit outweighs potential risk.”