A group of drugs commonly prescribed for heartburn, ulcers and acid reflux may lead to gradual yet "silent" kidney damage, warns a study.
The study evaluated the use of proton pump inhibitors (PPIs), which are sold under the brand names Prevacid, Prilosec, Nexium and Protonix, among others, in 125,000 patients.
More than half of patients who develop chronic kidney damage while taking the drugs do not experience acute kidney problems beforehand, meaning patients may not be aware of a decline in kidney function, the findings, published in the journal Kidney International, showed.
The onset of acute kidney problems is not a reliable warning sign for clinicians to detect a decline in kidney function among patients taking proton pump inhibitors, said the study's senior author Ziyad Al-Aly, Assistant Professor of Medicine at Washington University School of Medicine.
"Our results indicate kidney problems can develop silently and gradually over time, eroding kidney function and leading to long-term kidney damage or even renal failure. Patients should be cautioned to tell their doctors if they're taking PPIs and only use the drugs when necessary," Al-Aly said.
The researchers analysed data from the Department of Veterans Affairs databases on 125,596 new users of PPIs and 18,436 new users of other heartburn drugs referred to as H2 blockers.
The latter are much less likely to cause kidney problems but often are not as effective.
Over five years of follow up, the researchers found that more than 80 per cent of PPI users did not develop acute kidney problems, which often are reversible and are characterised by too little urine leaving the body, fatigue and swelling in the legs and ankles.
However, more than half of the cases of chronic kidney damage and end-stage renal disease associated with PPI use occurred in people without acute kidney problems.
End-stage renal disease occurs when the kidneys can no longer effectively remove waste from the body.
In such cases, dialysis or a kidney transplant is needed to keep patients alive.
"Doctors must pay careful attention to kidney function in their patients who use PPIs, even when there are no signs of problems," Al-Aly cautioned.