Laboratory evaluation of potassium and creatinine among ambulatory patients prescribed spironolactone: are we monitoring for hyperkalemia

UMMS Affiliation

Meyers Primary Care Institute

Publication Date


Document Type



Aged; *Ambulatory Care; Cohort Studies; Creatinine; *Drug Monitoring; Female; Humans; Hyperkalemia; Male; Potassium; Retrospective Studies; Spironolactone


Health Services Research | Primary Care


BACKGROUND: Serum potassium and creatinine evaluation is recommended in patients prescribed spironolactone, yet the proportion of ambulatory patients chronically dispensed spironolactone receiving evaluation is not well understood.

OBJECTIVE: To estimate the rate of potassium and creatinine evaluation and identify factors associated with conducting these tests among ambulatory patients dispensed spironolactone.

METHODS: A retrospective cohort study was designed to evaluate patients at 10 health maintenance organizations with ongoing spironolactone dispensing for one year (N = 2257). Potassium and creatinine evaluation were determined from administrative data. Associations between patient characteristics and laboratory testing were assessed, using logistic regression modeling.

RESULTS: Serum creatinine and potassium were evaluated in 72.3% of patients during a 13 month period. The likelihood of potassium and creatinine monitoring was greater among patients who were older (OR 1.28; 95% CI 1.17 to 1.41 per decade of life); male (OR 1.25; 95% CI 1.01 to 1.54); had diabetes (OR 1.63; 95% CI 1.31 to 2.03); received concomitant therapy with angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (OR 2.23; 95% CI 1.74 to 2.87), potassium supplements (OR 1.96; 95% CI 1.51 to 2.54), or digoxin (OR 2.10 95% CI 1.48 to 2.98); or had more outpatient visits (OR 1.31; 95% CI 1.19 to 1.44). Among patients with heart failure (n = 790), factors associated with the incidence of laboratory testing were diabetes (OR 1.64, 95% CI 1.14 to 2.34), outpatient visits (OR 1.20; 95% CI 1.02 to 1.41), and digoxin therapy (OR 2.26; 95% CI 1.38 to 3.69).

CONCLUSIONS: Three-fourths of ambulatory patients dispensed spironolactone receive recommended laboratory evaluation, with monitoring more likely to be completed in patients prescribed concomitant therapy with drugs that increase hyperkalemia risk, older patients, and those with diabetes.

DOI of Published Version



Ann Pharmacother. 2007 Feb;41(2):193-200. Epub 2007 Feb 6. Link to article on publisher's site

Journal/Book/Conference Title

The Annals of pharmacotherapy

Related Resources

Link to Article in PubMed

PubMed ID