ACE pills may cause buildup of potassium

Drugs used to treat high blood pressure and other conditions can cause a dangerous buildup of potassium, researchers say, and patients taking them need to be watched closely.

The drugs -- angiotensin-converting-enzyme, or ACE, inhibitors and angiotensin-receptor blockers -- can raise potassium levels in about 10% of patients, especially those with weak kidneys, said Dr. Biff Palmer of the University of Texas Southwestern Medical Center at Dallas.

“Because a third to half of patients with congestive heart failure have kidney complications, a large proportion of patients being treated with ACE inhibitors and angiotensin-receptor blockers are at increased risk for hyperkalemia (high potassium),” Palmer said.

Potassium is normally excreted by the kidneys, with levels in the blood affecting the way cell membranes work, and governs the action of the heart and pathways between the brain and muscles. High potassium levels can disrupt the heart’s normal rhythm, Palmer wrote in a commentary for Thursday’s New England Journal of Medicine.

“The patient’s medication profile should be reviewed and drugs discontinued that impair excretion of potassium in the kidney, such as over-the-counter non-steroidal anti-inflammatory drugs like ibuprofen and naproxen,” he said.

Patients at risk should avoid foods high in potassium such as orange juice, melons, bananas and salt substitutes.