January 30, 2013
Triple Combination of Common Drugs Can Damage Kidneys

MontrealA triple combination of blood pressure drugs and common painkillers, often prescribed to elderly patients with chronic conditions, may increase risk of acute kidney injury, especially at treatment initiation.

That’s according to a study published this month in BMJ, the British Medical Journal.

Researchers from the Jewish General Hospital and McGill University in Montreal, Canada, used the world's largest computerized database of primary care records to identify 487,372 patients who received antihypertensive drugs between 1997 and 2008. Drugs included angiotensin converting enzyme (ACE) inhibitors, angiotensin receptor blockers (ARBs), and diuretics, with NSAIDs. Over 6 years of tracking, 2,215 patients were diagnosed with acute kidney injury that prompted admission to a hospital or dialysis.

While patients taking a double-therapy combination of either a diuretic or an ACE inhibitor or ARB with an NSAID were at no increased risk of kidney injury, a triple-therapy combination of a diuretic with an ACE inhibitor or ARB and an NSAID was associated with a 31% higher rate of kidney injury overall. In the first 30 days of treatment, the rate was 82% higher.

The authors, who note that the absolute risk remained low, conclude that, “although antihypertensive drugs have cardiovascular benefits, vigilance may be warranted when they are used concurrently with NSAIDs.

“In particular, major attention should be paid early in the course of treatment, and a more appropriate choice among the available anti-inflammatory or analgesic drugs could therefore be applied in clinical practice,” they add.

An accompanying editorial by commentators from the London School of Hygiene and Tropical Medicine in the United Kingdom said the study “is an important step in the right direction" but "probably underestimates the true burden of drug associated acute kidney injury.”

The editorial authors suggested that pharmacists and other health care professionals advise patients of the risks and be vigilant for drug-associated acute kidney injury, but they also cautioned "the jury is still out on whether double drug combinations are indeed safe."

U.S. Pharmacist Social Connect