Moderate
Established
설명
Spironolactone can increase digoxin levels by reducing its renal clearance and may cross-react with some digoxin immunoassays, confounding monitoring.
기전
Spironolactone and its metabolite canrenone inhibit P-gp–mediated renal tubular secretion of digoxin; spironolactone's steroid structure also interferes with fluorescence polarization immunoassays for digoxin.
임상적 중요성
Digoxin toxicity (bradycardia, heart block, nausea, visual disturbances) can result from elevated levels; assay interference may overestimate or underestimate true digoxin levels.
관리 방법
Monitor digoxin levels using a liquid chromatography–based assay (not immunoassay) when spironolactone is co-administered; reduce digoxin dose if levels rise above 1.0–1.2 ng/mL.