title: Studies on the metabolism and pharmacokinetics of tamoxifen in normal volunteers.
abstract: The densitometric analytic procedure used for tamoxifen can also be used to quantify its desmethyl metabolite. In a study involving six healthy male volunteers, tamoxifen tablets were shown to be as bioavailable as a solution of tamoxifen citrate. After administration of a single dose of 20 mg, peak serum levels of tamoxifen were 42 ng/ml; those of the metabolite were 12 ng/ml. The half-lives of the drug and metabolite were approximately 4 and 9 days, respectively, after a single dose. After three widely separated single doses, a reversible increase in elimination half-life occurred.
mesh_terms: D000328:Adult; D003640:Dealkylation; D006207:Half-Life; D006801:Humans; D007700:Kinetics; D008297:Male; D012996:Solutions; D013607:Tablets; D013629:Tamoxifen / Q000008:administration & dosage / Q000378:metabolism*
chemical_list: D012996:Solutions; D013607:Tablets; D013629:Tamoxifen