Spironolactone
By antagonizing the mineralocorticoid receptor, spironolactone opposes aldosterone, the hormone that signals the kidney to retain sodium and excrete potassium. Blocking that signal makes it a potassium-sparing diuretic: it removes excess fluid and sodium while conserving potassium, easing the strain of fluid overload in heart failure and lowering blood pressure. Because it also blunts androgen activity, it is widely used for hormone-driven conditions including polycystic ovary syndrome and as an anti-androgen in hormone therapy. A steroidal small molecule (C24H32O4S) with a short parent half-life near 1.4 hours, its effect is prolonged by active metabolites. This combination of diuretic and anti-androgen properties gives it an unusually broad range of uses. Spironolactone is an approved medicine spanning cardiology and endocrinology.
This aldosterone-blocking diuretic removes excess fluid and sodium from the body while sparing potassium, reducing the strain of fluid overload on the heart and blood vessels. Beyond heart failure and hypertension, it is widely used for hormonal conditions including polycystic ovary syndrome and as an anti-androgen in hormone therapy.
Molecular Weight
416.5740 g/mol
LogP
2.90
TPSA
85.70 Ų
Lipinski RO5
Pass
Therapeutic Areas
Drug Classes
Mechanism of Action
Mineralocorticoid receptor antagonist.
Pharmacokinetics (PK)
Pharmacodynamics (PD)
Mineralocorticoid receptor antagonist.
2D Structure
Cite this structure
Embed this structure
SMILES
CC(=O)S[C@@H]1CC2=CC(=O)CC[C@]2(C)[C@H]2CC[C@@]3(C)[C@@H](CC[C@@]34CCC(=O)O4)[C@H]12
InChI
InChI=1S/C24H32O4S/c1-14(25)29-19-13-15-12-16(26)4-8-22(15,2)17-5-9-23(3)18(21(17)19)6-10-24(23)11-7-20(27)28-24/h12,17-19,21H,4-11,13H2,1-3H3/t17-,18-,19+,21+,22-,23-,24+/m0/s1
Molecular Formula
C24H32O4S
HBD / HBA
- / 5
Rotatable Bonds
2
Heavy Atoms
29
Spironolactone increases renal lithium reabsorption by promoting distal tubular sodium retention, leading to lithium toxicity.
Furosemide and spironolactone have complementary diuretic mechanisms that together provide more effective decongestion in heart failure; the primary concern is unpredictable electrolyte effects.
Spironolactone can increase digoxin levels by reducing its renal clearance and may cross-react with some digoxin immunoassays, confounding monitoring.
Ibuprofen reduces the diuretic and antihypertensive efficacy of spironolactone and may exacerbate renal insufficiency in high-risk patients.
Adding spironolactone to an ACE inhibitor substantially increases the risk of hyperkalemia, which can cause life-threatening cardiac arrhythmias.
ARBs combined with spironolactone substantially increase hyperkalemia risk through additive suppression of renal potassium excretion.
NSAIDs reduce the natriuretic and diuretic efficacy of spironolactone, potentially leading to sodium retention and worsening edema or hypertension.
No side effects recorded
Side effect data is not yet available for this drug.
Frequently Asked Questions
This aldosterone-blocking diuretic removes excess fluid and sodium from the body while sparing potassium, reducing the strain of fluid overload on the heart and blood vessels. Beyond heart failure and hypertension, it is widely used for hormonal conditions including polycystic ovary syndrome and as an anti-androgen in hormone therapy.
Mineralocorticoid receptor antagonist.
Key pharmacokinetic parameters for Spironolactone: Half-life: 1.4 hours.
Yes, Spironolactone is an approved drug. It has reached clinical phase 4. It is classified as a Small molecule.
Related Drugs
Same Drug Class
References & Data Sources
- ChEMBL — European Bioinformatics Institute (EBI). CHEMBL1393. Open-access bioactivity database.
- PubChem — National Center for Biotechnology Information (NCBI). CID 5833. Chemical information database.
Data aggregated from publicly available pharmacological databases. Last updated 2026-03-28.
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