A Dose of Prevention

New alert systems and biomarkers are spotting drug- induced kidney damage early, before irreversible harm

- By Jyoti Madhusoodanan

DENNIS MOLEDINA ENCOUNTERED a common problem during his training in nephrology, the specialty dedicated to kidney health. Many of the patients he saw had acute kidney injury that had been caused not directly by a disease but by a prescribed medication. Each encounter sparked a series of questions for Moledina: Should they stop the problem medicine? Was there a drug they could add to the regimen to protect the patient's kidneys? Should they biopsy the organs to determine the cause?

Acute kidney injury (AKI) is a sudden change in the kidneys' ability to filter waste products from the blood, and it affects approximately one in 10 hospitalized patients—a number that jumps to more than five in 10 for those in intensive care. But the condition often causes no pain or discomfort, and clinicians have few warning signs.

Drugs, including common antibiotics and painkillers, may treat ailments such as infections but harm the kidneys and worsen the overall problem. Some of these illnesses impair renal function as well. By the time blood levels of creatinine—a protein the kidneys typically remove—are high enough to grab a clinician's attention, it's often too late. Irreversible kidney damage has already begun. Because of the multitude of possible causes, identifying the real reason for drug-induced AKI in hospitalized people can be incredibly complex, and the condition is still underrecognized.

Historically, researchers and clinicians assumed that the kidneys healed when someone stopped taking medications and recovered from hospitalization. They would monitor patients during treatment—for instance, while they were taking a limited course of antibiotics—but didn't think short-term changes in creatinine resulted in lasting damage, says nephrologist Matthew James of the University of Calgary.