title: Plasma concentrations of estradiol and testosterone in single-drug polyestradiol phosphate therapy for prostatic cancer.
abstract: To evaluate the appropriate dosage of polyestradiol phosphate (PEP, Estradurin) as single-drug therapy, patients with metastatic prostatic carcinoma were given 80, 160 or 240 mg PEP every 4 weeks for at least 6 months. Injection of PEP was followed by rising plasma concentrations of estradiol in the first 2 weeks and slight fall in the next 2 weeks. Testosterone levels fell rapidly in the first 7 days and rose slightly in the following 3 weeks. Steady-state levels were reached after 2 months at the two lowest doses and after 4 months at the highest dose. Steady-state estradiol values increased in linear proportion to the dose. The steady-state concentrations of testosterone were about 45, 25 and 15% of the pretreatment values in the respective groups. At least 160 mg PEP at 4-week intervals is appropriate when the drug is used alone.
mesh_terms: D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000031:analogs & derivatives* / Q000097:blood* / Q000627:therapeutic use; D006801:Humans; D007273:Injections, Intramuscular; D007700:Kinetics; D008297:Male; D009919:Orchiectomy; D011471:Prostatic Neoplasms / Q000097:blood / Q000188:drug therapy* / Q000628:therapy; D011863:Radioimmunoassay; D013739:Testosterone / Q000097:blood*
chemical_list: D013739:Testosterone; D004958:Estradiol; C008958:polyestradiol phosphate