Case 13 - Primary Aldosteronism in a Patient Treated With Spironolactone

Abstract

Mineralocorticoid receptor antagonists (MRAs) (e.g., spironolactone and eplerenone) prevent aldosterone from activating the receptor, resulting, sequentially, in sodium loss, a decrease in plasma volume, and an elevation in renin. If plasma renin activity (PRA) or plasma renin concentration (PRC) is not suppressed in a patient treated with a MRA, then no further primary aldosteronism (PA)-related testing can be performed and the MRA should be discontinued for 6 weeks before retesting. However, if the patient is hypokalemic despite treatment with a MRA, then the mineralocorticoid receptors are not fully blocked, and PRA or PRC should be suppressed in such a patient with PA. In addition, most patients with PA are treated with suboptimal dosages of MRAs, and the mineralocorticoid receptors are not fully blocked. Thus for case detection testing, blood pressure medications, including MRAs, should not be discontinued. In the setting of suppressed PRA or PRC, clinicians can proceed with case detection testing in all patients treated with MRAs, and the MRA does not need to be discontinued for confirmatory or subtype testing with adrenal venous sampling (AVS).