Bifluranol Explained

Bifluranol (; brand name Prostarex; former developmental code name BX-341) is a synthetic nonsteroidal estrogen of the stilbestrol group related to diethylstilbestrol that has been used as an antiandrogen in the United Kingdom in the treatment of benign prostatic hyperplasia.^{[1] [2] [3] [4] [5] [6] [7] [8]} The drug is described as a weak estrogen, and possesses about one-eighth the potency of diethylstilbestrol.^[9]

In spite of the fact that it is widely referred to as an antiandrogen in the literature, bifluranol is actually a pure estrogen and does not significantly bind to the androgen receptor or directly antagonize the action of androgens. It exerts functional antiandrogen effects by binding to and activating the estrogen receptor in the pituitary gland, consequently suppressing the secretion of luteinizing hormone (and hence acting as an antigonadotropin) and thereby reducing gonadal androgen production and systemic androgen levels. Bifluranol has also been found to act as a 17α-hydroxylase/17,20 lyase inhibitor, though with less potency than ketoconazole, and this action may contribute to its efficacy in benign prostatic hyperplasia by further helping to lower androgen levels.^{[10] [11] [12]}

Related drugs include pentafluranol (BX-430) and terfluranol (BX-428), which are also estrogens.^[13]

See also

• Acefluranol
• Paroxypropione
• Metallibure

Notes and References

1. Book: Elks J . The Dictionary of Drugs: Chemical Data: Chemical Data, Structures and Bibliographies. 14 November 2014. Springer. 978-1-4757-2085-3. 152.
2. Book: Index Nominum 2000: International Drug Directory. January 2000. Taylor & Francis. 978-3-88763-075-1. 124–.
3. Dekanski JB . Anti-prostatic activity of bifluranol, a fluorinated bibenzyl . British Journal of Pharmacology . 71 . 1 . 11–16 . 1980 . 6258683 . 2044395 . 10.1111/j.1476-5381.1980.tb10903.x .
4. Pope DJ, Gilbert AP, Easter DJ, Chan RP, Turner JC, Gottfried S, Parke DV . Bifluranol, a novel fluorinated bibenzyl anti-androgen, its chemistry and disposition in different animal species . The Journal of Pharmacy and Pharmacology . 33 . 5 . 297–301 . May 1981 . 6116777 . 10.1111/j.2042-7158.1981.tb13784.x . 40258860 .
5. Beacock CJ, Buck AC, Roberts EE . Bifluranol in the treatment of benign prostatic hyperplasia (BPH). The Prostate. 7. 4. 1985. 357–361. 0270-4137. 10.1002/pros.2990070403. 71645575.
6. Keane PF, Timoney AG, Kiely E, Williams G, Stamp G . Response of the benign hypertrophied prostate to treatment with an LHRH analogue . British Journal of Urology . 62 . 2 . 163–165 . August 1988 . 2457404 . 10.1111/j.1464-410X.1988.tb04299.x .
7. Book: Spain. Ministerio de Agricultura. Universidad Complutense de Madrid. Departamento de Genetico y Mejora. 3rd World Congress of Animal Feeding. 1978. Industrias Gráficas España. 978-84-7391-022-4. 532.
8. Book: Annual Reports in Medicinal Chemistry. 16 September 1986. Academic Press. 978-0-08-058365-5. 182–.
9. Book: Agarwal MK . Receptor mediated antisteroid action. 1987. De Gruyter. 978-0-89925-374-9. 330.
10. Barrie SE, Rowlands MG, Foster AB, Jarman M . Inhibition of 17 alpha-hydroxylase/C17-C20 lyase by bifluranol and its analogues . Journal of Steroid Biochemistry . 33 . 6 . 1191–1195 . December 1989 . 2559252 . 10.1016/0022-4731(89)90429-9 .
11. Jarman M, Smith HJ, Nicholls PJ, Simons C . Inhibitors of enzymes of androgen biosynthesis: cytochrome P450(17) alpha and 5 alpha-steroid reductase . Natural Product Reports . 15 . 5 . 495–512 . October 1998 . 9807812 . 10.1039/a815495y .
12. Barrie SE, Haynes BP, Potter GA, Chan FC, Goddard PM, Dowsett M, Jarman M . Biochemistry and pharmacokinetics of potent non-steroidal cytochrome P450(17alpha) inhibitors . The Journal of Steroid Biochemistry and Molecular Biology . 60 . 5–6 . 347–351 . March 1997 . 9219927 . 10.1016/S0960-0760(96)00225-7 . 54340023 .
13. Book: Kubiak H, Wróbel J . Polska Akademia Nauk. Komitet Badania Polonii. II Kongres Uczonych Polskiego Pochodzenia: zbiór materiałów. 1984. Zakład Narodowy im. Ossolińskich. 978-83-04-01670-5. [This explains why the estrogenic activity is minimal in terms of pentafluranol or even bifluranol. Doses which shall apply from 1 to 6 days of pregnancy, are in micrograms per kg of body weight: bifluranol 80, 30 and terfluranol pentafluranol 280 ...].