Mepitiostane

Mepitiostane

Clinical data
Trade names	Thioderon
Other names	10364-S; Epitiostanol 17β-(1-methoxy)cyclopentyl ether; 17β-[(1-Methoxycyclopentyl)oxy]-2α,3α-epithio-5α-androstane
AHFS/Drugs.com	International Drug Names
Routes of administration	By mouth
Drug class	Androgen; Anabolic steroid; Androgen ether; Antiestrogen
ATC code	None
Legal status
Legal status	In general: ℞ (Prescription only)
Identifiers
IUPAC name (1S,2S,4R,8S,11R,12S,15S,16S)-15-[(1-methoxycyclopentyl)oxy]-2,16-dimethyl-5-thiapentacyclo[9.7.0.02,8.04,6.012,16]octadecane
CAS Number	21362-69-6 Y
PubChem CID	9909202
ChemSpider	8084854 N
UNII	O00404969K
KEGG	D01602 Y
Chemical and physical data
Formula	C25H40O2S
Molar mass	404.65 g·mol−1
3D model (JSmol)	Interactive image
SMILES C[C@]12CC[C@H]3[C@H]([C@@H]1CC[C@@H]2OC4(CCCC4)OC)CC[C@@H]5[C@@]3(C[C@@H]6[C@H](C5)S6)C
InChI InChI=1S/C25H40O2S/c1-23-13-10-19-17(7-6-16-14-20-21(28-20)15-24(16,19)2)18(23)8-9-22(23)27-25(26-3)11-4-5-12-25/h16-22H,4-15H2,1-3H3/t16-,17-,18-,19-,20-,21+,22-,23-,24-/m0/s1 N Key:IVDYZAAPOLNZKG-KWHRADDSSA-N N
NY (what is this?)  (verify)

Mepitiostane, sold under the brand name Thioderon, is an orally active antiestrogen and anabolic–androgenic steroid (AAS) of the dihydrotestosterone (DHT) group which is marketed in Japan as an antineoplastic agent for the treatment of breast cancer. It is a prodrug of epitiostanol. The drug was patented and described in 1968.

Medical uses

Mepitiostane is used as an antiestrogen and antineoplastic agent in the treatment of breast cancer. It is also used as an AAS in the treatment of anemia of renal failure. A series of case reports have found it to be effective in the treatment of an estrogen receptor (ER)-dependent meningiomas as well.

Side effects

Mepitiostane shows a high rate of virilizing side effects such as acne, hirsutism, and voice changes in women.

Pharmacology

Pharmacodynamics

Mepitiostane is described as similar to tamoxifen as an antiestrogen, and through its active form epitiostanol, binds directly to and antagonizes the ER. It is also an AAS.

Pharmacokinetics

Mepitiostane is converted into epitiostanol in the body.

Chemistry

Mepitiostane, also known as epitiostanol 17β-(1-methoxy)cyclopentyl ether, is a synthetic androstane steroid and a derivative of DHT. It is the C17β (1-methoxy)cyclopentyl ether of epitiostanol, which itself is 2α,3α-epithio-DHT or 2α,3α-epithio-5α-androstan-17β-ol. A related AAS is methylepitiostanol (17α-methylepitiostanol), which is an orally active variant of epitiostanol similarly to mepitiostane, though also has a risk of hepatotoxicity.

Society and culture

Generic names

Mepitiostane is the generic name of the drug and its INN and JAN.