Spironolactone

Category: pharmacological

Aliases: Aldactone

Pharmacological Mechanism

Aldosterone receptor antagonist (mineralocorticoid receptor) — K+-sparing diuretic; also weak androgen receptor antagonist (used off-label for acne, female-pattern hair loss, PCOS). Hyperkalemia risk; gynecomastia from anti-androgen activity.

Half-Life (t½)

PO: 1.5h

Dosing Guidelines

• PO: Typical 50 mg (Range: 25–200 mg)

Target Organ Systems

• endocrine
• renal
• reproductive
• integumentary

Pathways It Modulates

• Androgenetic alopecia (inhibitor) — AR + adrenal androgen synthesis — oral for female AGA
• Estrogen receptor (ERα / ERβ / GPER) (inhibitor) — androgen-receptor + weak ER off-target (gynecomastia mechanism partial)
• Mineralocorticoid receptor (inhibitor) — MR (steroidal, non-selective)
• Progesterone receptor signaling (inhibitor) — PR (weak off-target — main action is MR + androgen)
• Renal tubular transport (inhibitor) — MR (upstream of ENaC)
• Renin-angiotensin-aldosterone axis (inhibitor) — mineralocorticoid receptor (also AR + progesterone receptor — gynecomastia)
• Steroid hormone biosynthesis (inhibitor) — 17α-hydroxylase / 17,20-lyase (off-target; basis for gynecomastia)

Chemical Identifiers

• PubChem CID: 5833
• Formula: C24H32O4S
• Molecular weight: 416.57 g/mol
• InChIKey: LXMSZDCAJNLERA-ZHYRCANASA-N
• SMILES: CC(=O)S[C@@H]1CC2=CC(=O)CC[C@@]2([C@@H]3[C@@H]1[C@@H]4CC[C@]5([C@]4(CC3)C)CCC(=O)O5)C

References

• PMID 26073023