Issue 156 Item 12 Low-Dose Eplerenone (Inspra™) Reduces Proteinuria in Type 2 Di

Eplerenone with enalapril reduces elevated potassium levels. Eplerenone at a dose of 50 to 100 mg co-administered with the ACE-inhibitor enalapril produces a similar antiproteinuric effect as eplerenone at a dose of 200 mg, while obviating the elevated potassium levels seen with the higher dose, researchers report.

The finding was presented on May 15th at the 18th Annual Scientific Meeting of the American Society of Hypertension.

Eplerenone, a selective aldosterone blocker recently approved for the treatment of hypertension, was previously shown to decrease proteinuria but also to increase potassium levels at a dose of 200 mg daily. Murray Epstein, MD of the University of Miami in Miami, Florida, led a team of researchers in determining whether lower doses of eplerenone would be as effective while reducing this dangerous side effect.

The multi-centre study included 268 patients with Type 2 diabetes and albuminuria (with or without a history of hypertension) being treated with enalapril 20 mg.

Patients were randomised to eplerenone 50 mg or 100 mg daily, or placebo in addition to their enalapril therapy. If their blood pressure was not controlled at Week 4, amlodipine 2.5 mg was added, with the dose doubled every two weeks, up to 10 mg, if necessary.

Uncontrolled hypertension was defined as levels greater than 130/80 mm Hg.. Patients were assessed at weeks 4, 8, and 12.

Patients who received eplerenone and enalapril in combination had a significantly reduced urinary albumin:creatinine ratio compared with the enalapril monotherapy group.

Incidence of both sustained and severe potassium increases were similar in the three treatment groups, and were not clinically relevant. The incidence rates were generally lower in patients receiving 50 mg or 100 mg eplerenone co-administered with enalapril when compared with results from an earlier trial that used eplerenone 200 mg with or without enalapril 10 mg in hypertensive patients with diabetes and albuminuria (Epstein et al. Am J Hypertens 2002;15(Suppl 1):A24).

Other adverse events (including gynaecomastia, mastodynia, and impotence) were rare or absent and did not differ among treatment groups.

This study was sponsored by Pharmacia Corporation of Peapack, New Jersey.

[Study title: Characterization of the Antiproteinuric Effect of Eplerenone in Patients with Type 2 Diabetes Mellitus. Abstract P-181a]