osaterone acetate osaterone acetate osaterone acetate, sold under the brand name ypozane, is a medication which is used in veterinary medicine in europe in the treatment of enlarged prostate in dogs. it is given by mouth. osaterone acetateclinical datatrade namesypozaneother namestzp-4238; gestoxarone acetate; 2-oxachloromadinone acetate; 17α-acetoxy-6-chloro-2-oxa-6-dehydroprogesterone; 17α-acetoxy-6-chloro-2-oxapregna-4,6-diene-3,20-dioneroutes ofadministrationby mouth (tablets)drug classsteroidal antiandrogen; progestogen; progestin; progestogen esterpharmacokinetic dataprotein bindingosaterone acetate: 90%15β-hydroxyosaterone acetate: 80%(both mainly to albumin)metabolismlivermetabolites15β-hydroxyosaterone acetateelimination half-lifedogs: 80 hours to 197 ± 109 hoursexcretionbile: 60%urine: 25%identifiers iupac name isochromen-1-yl] acetate cas number105149-00-6pubchem cid114992chemspider102924uniifr26fsv5ezkeggd11105echa infocard100.215.750 chemical and physical dataformulac22h27clo5molar mass406.90 g·mol−13d model (jsmol)interactive image smiles cc(=o)c1(ccc2c1(ccc3c2c=c(c4=cc(=o)occ34c)cl)c)oc(=o)c inchi inchi=1s/c22h27clo5/c1-12(24)22(28-13(2)25)8-6-16-14-9-18(23)17-10-19(26)27-11-20(17,3)15(14)5-7-21(16,22)4/h9-10,14-16h,5-8,11h2,1-4h3/t14-,15+,16+,20-,21+,22+/m1/s1key:kktiomqdfoycen-ofuybiassa-n osaterone acetate is an antiandrogen, and hence is an antagonist of the androgen receptor, the biological target of androgens like testosterone and dihydrotestosterone. it is also a progestin, or a synthetic progestogen, and hence is an agonist of the progesterone receptor, the biological target of progestogens like progesterone. osaterone acetate was introduced for veterinary use in 2007. it is marketed in europe. uses veterinary osaterone acetate is used in veterinary medicine in europe in the treatment of benign prostatic hyperplasia (bph) in dogs. it has been found to produce remission of clinical symptoms of bph in 83% of dogs for six months after a single one-week course of treatment, and can be used long-term. available forms osaterone acetate comes in the form of 1.875 mg, 3.75 mg, 7.5 mg, and 15 mg oral tablets for veterinary use. side effects side effects of osaterone acetate include diminished sperm quality (for up to 6 weeks post-treatment), transient elevation of liver enzymes (caution should be observed with known liver disease), vomiting, diarrhea, polyuria/polydipsia, lethargy, and hyperplasia of the mammary glands. it can also decrease cortisol levels, interfere with adrenocorticotropic hormone response, induce or exacerbate adrenal insufficiency, and exacerbate diabetes mellitus. pharmacology pharmacodynamics osaterone acetate is a steroidal antiandrogen, progestin, and antigonadotropin. it has virtually no estrogenic or androgenic activity. its side-effect profile indicates that it possesses clinically relevant glucocorticoid activity. an active metabolite of osaterone acetate, 15β-hydroxyosaterone acetate, has potent antiandrogenic activity similarly to osaterone acetate. osaterone acetate treats bph in dogs by reducing the actions of androgens in the prostate gland. pharmacokinetics the major active metabolite of osaterone acetate is 15β-hydroxyosaterone acetate. osaterone acetate has a long biological half-life of 80 hours to 197 ± 109 hours in dogs. chemistry