Spironolactone Use in Practice: Risk for Hyperkalemia?

In the RALES randomized, placebo-controlled trial, 25 mg daily of the aldosterone antagonist spironolactone significantly reduced mortality risk among patients with severe heart failure and left-ventricular systolic dysfunction (N Engl J Med 1999; 341:709). Spironolactone is a potassium-sparing diuretic that can cause hyperkalemia, especially at higher doses and in patients with renal dysfunction. RALES subjects rarely experienced hyperkalemia, but some experts have raised concerns about applying the RALES findings in practice. To address this issue, researchers used medical-records databases in Ontario to study rates of spironolactone use and rates of hyperkalemia-related hospitalization before and after RALES was published in 1999.

Spirono…