Polyestradiol phosphate

Contraindicated L02AA02(WHO) In general: ℞ (Prescription only) Estra-1,3,5(10)-triene-3,17β-diol, polymer with phosphoric acid 28014-46-2Y 51091766 DB09369Y None P14877CDX2 D07434Y ChEMBL1201477Y Interactive image [*]Oc1ccc2[C@H]3CC[C@]4(C)[C@]5(CC[C@H]4[C@@H]3CCc2c1).O5P([*])(=O)O Polyestradiol phosphate(PEP), sold under the brand nameEstradurin, is anestrogenmedication which is used primarily in the treatment ofprostate cancerin men.It is also used in women to treatbreast cancer, as a component ofhormone therapyto treatlow estrogen levelsandmenopausalsymptoms‍‍‍‍‍‍​​​‍​​​​​​, and as a component offeminizing hormone therapyfortransgender women.It is given byinjection into muscleonce every four weeks. Commonside effectsof PEP includeheadache,breast tenderness,breast development,feminization,sexual dysfunction,infertility, andvaginal bleeding.PEP is anestrogenand hence is anagonistof theestrogen receptor, thebiological targetofestrogenslikeestradiol.It is anestrogen esterin the form of apolymerand is an extremely long-lastingprodrugofestradiolin the body.Thebiological half-lifeof PEP is more than two months.Because PEP works by being converted into estradiol, it is considered to be anaturalandbioidenticalform of estrogen.Thesafetyprofile ofparenteralestradiol esters like PEP is greatly improved relative tosyntheticoralestrogens likeethinylestradiolanddiethylstilbestrol. PEP was discovered around 1953 and was introduced for medical use in theUnited Statesin 1957.Along withestradiol undecylateandestradiol valerate, it has been frequently used in the United States andEuropeas a parenteral form of estrogen to treat men with prostate cancer.However, it is no longer available in the United States.