Noretisteron: Perbedaan antara revisi
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====Efek antigonadotropik====
Karena aktivitas progestogeniknya, norethisterone menekan sumbu hipotalamus-hipofisis-gonad (sumbu HPG) dan karenanya memiliki efek antigonadotropik.
Dosis norethisterone oral dan NETA oral yang menghambat ovulasi adalah sekitar 0,5 mg/hari pada wanita.<ref name="pmid16112947" /><ref name="Rudel1968">{{cite journal | vauthors = Rudel HW | title = Pharmacology of oral contraceptives | journal = Clinical Obstetrics and Gynecology | volume = 11 | issue = 3 | pages = 632–44 | date = September 1968 | pmid = 4878826 | doi = 10.1097/00003081-196811030-00002 }}</ref><ref name="pmid14667980">{{cite journal | vauthors = Stanczyk FZ | title = All progestins are not created equal | journal = Steroids | volume = 68 | issue = 10–13 | pages = 879–90 | date = November 2003 | pmid = 14667980 | doi = 10.1016/j.steroids.2003.08.003 | s2cid = 44601264 }}</ref> Namun, ada beberapa data yang bertentangan, yang menunjukkan bahwa dosis yang lebih tinggi mungkin diperlukan untuk menghambat ovulasi sepenuhnya.<ref name="pmid22078182">{{cite journal | vauthors = Endrikat J, Gerlinger C, Richard S, Rosenbaum P, Düsterberg B | title = Ovulation inhibition doses of progestins: a systematic review of the available literature and of marketed preparations worldwide | journal = Contraception | volume = 84 | issue = 6 | pages = 549–57 | date = December 2011 | pmid = 22078182 | doi = 10.1016/j.contraception.2011.04.009}}</ref> Suntikan NETE 200 mg intramuskular telah terbukti mencegah ovulasi dan menekan kadar estradiol, progesteron, hormon luteinizing (LH), dan hormon perangsang folikel (FSH) pada wanita.<ref name="Shoupe1993">{{cite book| vauthors = Shoupe D | title=Contraception| chapter=Injectable Contraceptives and Contraceptive Vaginal Rings| series=Clinical Perspectives in Obstetrics and Gynecology|year=1993|pages=144–157| publisher=Springer|issn=0178-0328|doi=10.1007/978-1-4612-2730-4_13|isbn=978-1-4612-7645-6}}</ref><ref name="pmid1122756">{{cite journal | vauthors = Weiner E, Johansson ED | title = Plasma levels of norethindrone after i.m. injection of 200 mg norethindrone enanthate | journal = Contraception | volume = 11 | issue = 4 | pages = 419–25 | date = April 1975 | pmid = 1122756 | doi = 10.1016/0010-7824(75)90004-9 }}</ref><ref name="pmid606499">{{cite journal | vauthors = Fotherby K, Howard G, Shrimanker K, Elder M, Bye PG | title = Effect of norethisterone oenanthate on serum gonadotrophin levels | journal = Contraception | volume = 16 | issue = 6 | pages = 591–604 | date = December 1977 | pmid = 606499 | doi = 10.1016/0010-7824(77)90060-9 }}</ref><ref name="pmid572279">{{cite journal | vauthors = Goebelsmann U, Stanczyk FZ, Brenner PF, Goebelsmann AE, Gentzschein EK, Mishell DR | title = Serum norethindrone (NET) concentrations following intramuscular NET enanthate injection. Effect upon serum LH, FSH, estradiol and progesterone | journal = Contraception | volume = 19 | issue = 3 | pages = 283–313 | date = March 1979 | pmid = 572279 | doi = 10.1016/0010-7824(79)90022-2 }}</ref>
Studi awal tentang norethisterone oral pada pria yang menggunakan dosis 20 hingga 50 mg/hari mengamati penekanan ekskresi 17-ketosteroid, peningkatan ekskresi estrogen (karena konversi menjadi etinilestradiol), penekanan spermatogenesis, libido, dan fungsi ereksi, dan kejadian ginekomastia.<ref
[[File:Hormone levels in men with a single intramuscular injection of 5 mg estradiol valerate and 50 mg norethisterone enanthate in oil.png|thumb|right|450px|Tingkat hormon setelah suntikan intramuskular tunggal estradiol valerat/noretisteron enantat (5 mg/50 mg) pada pria muda yang sehat. Kadar testosteron ditekan secara maksimal sekitar 94% hingga ~30 ng/dL, bila diukur pada hari ke 7 pasca injeksi.<ref name="ValleAlvarez2011" />]]
Suntikan NETE intramuskular 200 mg tunggal atau dalam kombinasi dengan 2 mg estradiol valerat telah terbukti menghasilkan penurunan kadar gonadotropin dan testosteron yang cepat, kuat, dan berkelanjutan hingga satu bulan pada pria.<ref name="KamischkeNieschlag2004" /><ref name="Amory2003">{{cite book| vauthors = Amory JK |title=Androgens in Health and Disease |chapter=Androgens and Male Contraception |series=Contemporary Endocrinology |year=2003|pages=405–417|publisher=Humana Press |doi=10.1007/978-1-59259-388-0_21|isbn=978-1-61737-314-5}}</ref><ref name="pmid10971453">{{cite journal | vauthors = Kamischke A, Diebäcker J, Nieschlag E | title = Potential of norethisterone enanthate for male contraception: pharmacokinetics and suppression of pituitary and gonadal function | journal = Clinical Endocrinology | volume = 53 | issue = 3 | pages = 351–358 | date = September 2000 | pmid = 10971453 | doi = 10.1046/j.1365-2265.2000.01097.x | s2cid = 70515136 }}</ref> Suntikan NETE 200 mg intramuskular setiap 3 minggu sekali juga terbukti menekan spermatogenesis pada pria.<ref name="pmid793446">{{cite journal | vauthors = Neumann F, Diallo FA, Hasan SH, Schenck B, Traore I | title = The influence of pharmaceutical compounds on male fertility | journal = Andrologia | volume = 8 | issue = 3 | pages = 203–235 | date = 1976 | pmid = 793446 | doi = 10.1111/j.1439-0272.1976.tb02137.x | s2cid = 24859886 | doi-access = free }}</ref><ref name="PetryMauss1970">{{cite book| vauthors = Petry R, Mauss J, Senge T, Rausch-Stroomann JG |title=Über den Einfluß von Cyproteronacetat, Norethisteronönanthat und Gestonoroncapronat auf die Hypophysen-Gonadenachse beim Mann|chapter=Influence of Cyproterone-acetate, Norethisterone-enanthate and Gestonorone-capronate on the Hypophyseal-Gonadal-Axis in the Male |trans-title=Influence of Cyproterone-acetate, Norethisterone-enanthate and Gestonorone-capronate on the Hypophyseal-Gonadal-Axis in the Male|year=1970|pages=428–430|doi=10.1007/978-3-642-80591-2_118|journal=Endokrinologie der Entwicklung und Reifung|series=Symposion der Deutschen Gesellschaft für Endokrinologie in Ulm vom 26.—28. Februar 1970 |publisher=Springer |isbn=9783642805912 }}</ref> Demikian pula, suntikan intramuskular tunggal 50 mg NETE yang dikombinasikan dengan 5 mg estradiol valerat terbukti sangat menekan kadar testosteron pada pria.<ref name="ValleAlvarez2011">{{cite thesis | type = MSc | vauthors = Alvarez BD | title = Efecto de una Dosis de 50 mg de Enantato de Noretisterona y 5 mg de Valerato de Estradiol en los Niveles de Testosterona Total en Hombres Mexicanos Sanos | trans-title = Effect of a Dose of 50 mg of Norethisterone Enanthate and 5 mg of Estradiol Valerate on Total Testosterone Levels in Healthy Mexican Men | date = 11 May 2011 | publisher = National Polytechnic Institute of Mexico | url = http://repositoriodigital.ipn.mx/handle/123456789/12490 | access-date = 12 September 2022 | archive-date = 16 September 2022 | archive-url = https://web.archive.org/web/20220916063742/https://repositoriodigital.ipn.mx/handle/123456789/12490 | url-status = live }}</ref> Kadar testosteron menurun dari ~503 ng/dL pada awal menjadi ~30 ng/dL pada titik terendah (–94%) yang terjadi pada hari ke 7 pasca injeksi.<ref name="ValleAlvarez2011" />
===Farmakokinetik===
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