Formestane

{{Short description|Chemical compound}}

{{Drugbox

| Verifiedfields = changed

| Watchedfields = changed

| verifiedrevid = 437193284

| IUPAC_name = (8R,9S,10R,13S,14S)-4-hydroxy-10,13-dimethyl-2,6,7,8,9,11,12,14,15,16-decahydro-1H-cyclopenta[a]phenanthrene-3,17-dione

| image = Formestane.svg

| width = 225px

| tradename = Lentaron, others

| Drugs.com = {{drugs.com|international|formestane}}

| pregnancy_category =

| legal_status =

| routes_of_administration = Intramuscular injection

| class = Aromatase inhibitor; Antiestrogen

| bioavailability =

| protein_bound =

| metabolism =

| elimination_half-life =

| excretion =

| CAS_number_Ref = {{cascite|correct|??}}

| CAS_number = 566-48-3

| ATC_prefix = L02

| ATC_suffix = BG02

| PubChem = 11273

| DrugBank_Ref = {{drugbankcite|correct|drugbank}}

| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}

| ChemSpiderID = 10799

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = PUB9T8T355

| KEGG_Ref = {{keggcite|correct|kegg}}

| KEGG = D07260

| ChEBI_Ref = {{ebicite|changed|EBI}}

| ChEBI = 75172

| ChEMBL_Ref = {{ebicite|correct|EBI}}

| ChEMBL = 132530

| synonyms = 4-Hydroxyandrost-4-ene-3,17-dione

| C=19 | H=26 | O=3

| SMILES = O=C4C(/O)=C3/CC[C@@H]2[C@H](CC[C@@]1(C(=O)CC[C@H]12)C)[C@@]3(C)CC4

| StdInChI_Ref = {{stdinchicite|correct|chemspider}}

| StdInChI = 1S/C19H26O3/c1-18-10-8-15(20)17(22)14(18)4-3-11-12-5-6-16(21)19(12,2)9-7-13(11)18/h11-13,22H,3-10H2,1-2H3/t11-,12-,13-,18+,19-/m0/s1

| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}

| StdInChIKey = OSVMTWJCGUFAOD-KZQROQTASA-N

}}

Formestane, formerly sold under the brand name Lentaron among others, is a steroidal, selective aromatase inhibitor which is used in the treatment of estrogen receptor-positive breast cancer in postmenopausal women.{{cite journal |vauthors=Pérez Carrión R, Alberola Candel V, Calabresi F |title=Comparison of the selective aromatase inhibitor formestane with tamoxifen as first-line hormonal therapy in postmenopausal women with advanced breast cancer |journal=Ann. Oncol. |volume=5 |pages=S19–24 |year=1994 |issue=Suppl 7 |pmid=7873457 |display-authors=etal}} The drug is not active orally, and was available only as an intramuscular depot injection. Formestane was not approved by the United States FDA and the injectable form that was used in Europe in the past has been withdrawn from the market.{{Cite web|url=https://pubchem.ncbi.nlm.nih.gov/compound/formestane#section=Top|title = Formestane}} Formestane is an analogue of androstenedione.

Formestane is often used to suppress the production of estrogens from anabolic steroids or prohormones. It also acts as a prohormone to 4-hydroxytestosterone, an active steroid which displays weak androgenic activity in addition to acting as a weak aromatase inhibitor.[https://steroiduck.com/shop/anavar-for-sale/ Where to Buy Anavar]

{{Pharmacodynamics of aromatase inhibitors}}