Hyperkalaemia and impaired renal function in patients taking spironolactone for congestive heart failure: retrospective study

Spironolactone reduces disease and death in patients with severe congestive heart failure and is well tolerated with regard to renal function and serum potassium concentrations.1 Guidelines recommend taking spironolactone in addition to angiotensin converting enzyme inhibitors and β blockers,2 3 but since spironolactone can lead to renal dysfuction or hyperkalaemia, we followed up a cohort of patients taking spironolactone to identify predictors of harmful effects. We selected 125 consecutive patients from the congestive heart failure outpatient clinic of Frederiksberg University Hospital, Copenhagen (table).4 We included only patients with a left ventricular ejection fraction (LVEF) of no more than 45% or patients who were taking spironolactone. We started 65 patients on spironolactone; 60 patients were already taking spironolactone when they were referred. We measured blood electrolytes at baseline and then every two months. The study started in September 1999 …