Spironolactone is a prodrug with a short terminal half-life of 1.4 hours.[5][6][7] The active metabolites of spironolactone have extended terminal half-lives of 13.8 hours for 7α-TMS, 15.0 hours for 6β-OH-7α-TMS, and 16.5 hours for canrenone, and accordingly, these metabolites are responsible for the therapeutic effects of the drug.[5][6]
7α-TS and 7α-TMS have been found to possess approximately equivalent affinity for the rat ventral prostateandrogen receptor (AR) relative to that of spironolactone.[8] The affinity of 7α-TS, 7α-TMS, and spironolactone for the rat prostate AR is about 3.0 to 8.5% of that of dihydrotestosterone (DHT).[8]
^ abSica DA (2005). "Pharmacokinetics and pharmacodynamics of mineralocorticoid blocking agents and their effects on potassium homeostasis". Heart Fail Rev. 10 (1): 23–9. doi:10.1007/s10741-005-2345-1. PMID15947888. S2CID21437788.
^ abCutler GB, Pita JC, Rifka SM, Menard RH, Sauer MA, Loriaux DL (1978). "SC 25152: A potent mineralocorticoid antagonist with reduced affinity for the 5 alpha-dihydrotestosterone receptor of human and rat prostate". J. Clin. Endocrinol. Metab. 47 (1): 171–5. doi:10.1210/jcem-47-1-171. PMID263288.
^Colby HD, O'Donnell JP, Flowers NL, Kossor DC, Johnson PB, Levitt M (April 1991). "Relationship between covalent binding to microsomal protein and the destruction of adrenal cytochrome P-450 by spironolactone". Toxicology. 67 (2): 143–54. doi:10.1016/0300-483X(91)90138-Q. PMID2031249.
^Kossor DC, Kominami S, Takemori S, Colby HD (August 1991). "Role of the steroid 17 alpha-hydroxylase in spironolactone-mediated destruction of adrenal cytochrome P-450". Mol. Pharmacol. 40 (2): 321–5. PMID1875914.
^Decker CJ, Rashed MS, Baillie TA, Maltby D, Correia MA (June 1989). "Oxidative metabolism of spironolactone: evidence for the involvement of electrophilic thiosteroid species in drug-mediated destruction of rat hepatic cytochrome P450". Biochemistry. 28 (12): 5128–36. doi:10.1021/bi00438a033. PMID2765527.
^Gardiner P, Schrode K, Quinlan D, Martin BK, Boreham DR, Rogers MS, Stubbs K, Smith M, Karim A (1989). "Spironolactone metabolism: steady-state serum levels of the sulfur-containing metabolites". J Clin Pharmacol. 29 (4): 342–7. doi:10.1002/j.1552-4604.1989.tb03339.x. PMID2723123. S2CID29457093.
^Pugeat MM, Dunn JF, Nisula BC (1981). "Transport of steroid hormones: interaction of 70 drugs with testosterone-binding globulin and corticosteroid-binding globulin in human plasma". J. Clin. Endocrinol. Metab. 53 (1): 69–75. doi:10.1210/jcem-53-1-69. PMID7195405.
Further reading
Gardiner P, Schrode K, Quinlan D, Martin BK, Boreham DR, Rogers MS, Stubbs K, Smith M, Karim A (1989). "Spironolactone metabolism: steady-state serum levels of the sulfur-containing metabolites". J Clin Pharmacol. 29 (4): 342–7. doi:10.1002/j.1552-4604.1989.tb03339.x. PMID2723123. S2CID29457093.