Pharmacokinetics of toremifene.
The pharmacokinetics of toremifene has been investigated in man after single and multiple oral doses. Toremifene was completely absorbed without first-pass metabolism. Peak concentration in serum was achieved in 4 h. Mean half-lives of distribution and elimination were 4 h and 5 days, respectively. Kinetics was linear in the studied dose-range of 10-680 mg. Toremifene was over 99% bound to plasma proteins and extensively metabolized. The main metabolites in serum were demethyl- and deaminohydroxytoremifene. In patients receiving multiple dosing of 60 mg/day serum steady-state level of toremifene was 0.8 microgram/ml on average. The level of demethyl metabolite was twice and that of deaminohydroxy metabolite was one tenth of toremifene.
Anttila
M
M
Farmos Group Ltd., Research Center, Turku, Finland.
Valavaara
R
R
Kivinen
S
S
Mäenpää
J
J
D001682:Biological Availability; D004334:Drug Administration Schedule; D004965:Estrogen Antagonists / Q000008:administration & dosage / Q000378:metabolism / Q000493:pharmacokinetics*; D005243:Feces / Q000032:analysis; D005260:Female; D006801:Humans; D007408:Intestinal Absorption; D013629:Tamoxifen / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000378:metabolism / Q000493:pharmacokinetics; D017312:Toremifene
D004965:Estrogen Antagonists; D013629:Tamoxifen; D017312:Toremifene