Severe hyperkalemia rarely occurs as a result of dual blockade of the renin-angiotensin-aldosterone system (RAAS) or intensive blood pressure (BP) control, according to a study.

Ronald D. Perrone, MD, of Tufts Medical Center in Boston, and colleagues analyzed the frequency and severity of hyperkalemia in the HALT-PKD trial, a prospective, randomized study designed to determine the effects of dual RAAS blockade and BP reduction on progression of autosomal dominant polycystic kidney disease

The trial had 2 study groups. Study A participants had an estimated glomerular filtration rate (eGFR) greater than 60 mL/min/1.73 m2. These patients were randomly assigned to receive lisinopril plus placebo or lisinopril plus telmisartan, with 2 levels of BP control: standard BP (SBP, 120–130/70–80 mm Hg or low BP (LBP, 95–110/65–75 mm Hg). Study B included patients with an eGFR of 25–60 mL/min/1.73 m2 randomized to lisinopril plus placebo or lisinopril plus telmisartan, with SBP control only.

Hyperkalemia rarely developed in study A participants. Mild hyperkalemia (potassium levels higher than 5.5 but not more than 6 mEq/L) occurred in 3%, 1%, 3%, and 2% of subjects in the lisinopril/telmisartan, lisinopril/placebo, SBP, and LBP arms, respectively, Dr. Perrone’s group reported at Kidney Week 2015 in San Diego. Moderate hyperkalemia (potassium levels higher than 6 but not more than 6.5 mEq/L) developed in 2%, 0.4%, 1%, and 1%, respectively. Severe hyperkalemia (potassium levels above 6.5 mEq/L) developed in 0.4%, 0%, 0%, and 0.4%.

Mild hyperkalemia was more common among study B participants, but it was easily managed, according to the investigators. It occurred in 17% of the lisinopril/telmisartan arm and 16% of the lisinopril/placebo arm. Moderate hyperkalemia developed in 4% and 12%, respectively, and severe hyperkalemia developed in 0% and 0.4%, respectively.

“With careful management, dual RAAS blockade and intensive BP control were safe in the HALT PKD trial,” the researchers concluded in their study abstract.