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| Clinical data | |
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| Trade names | Prostarex |
| Other names | BX-341 |
| Drug class | Nonsteroidal estrogen |
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| ChEMBL | |
| Chemical and physical data | |
| Formula | C17H18F2O2 |
| Molar mass | 292.326 g·mol−1 |
| 3D model (JSmol) | |
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Bifluranol (INNTooltip International Nonproprietary Name,BANTooltip British Approved Name; brand nameProstarex; former developmental code nameBX-341) is asyntheticnonsteroidal estrogen of thestilbestrol group related todiethylstilbestrol that has been used as anantiandrogen in theUnited Kingdom in the treatment ofbenign 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.[3][7][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 theandrogen receptor or directlyantagonize the action ofandrogens.[3] It exerts functional antiandrogen effects by binding to and activating theestrogen receptor in thepituitary gland, consequently suppressing the secretion ofluteinizing hormone (and hence acting as anantigonadotropin) and thereby reducinggonadal androgen production and systemic androgen levels.[3] Bifluranol has also been found to act as a17α-hydroxylase/17,20 lyaseinhibitor, though with lesspotency thanketoconazole, and this action may contribute to its efficacy in benign prostatic hyperplasia by further helping to lower androgen levels.[10][11][12]
Related drugs includepentafluranol (BX-430) andterfluranol (BX-428), which are also estrogens.[13]
[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 ...]