title: Fenoterol metabolism in man: sulphation versus glucuronidation.
abstract: 1. Plasma levels of fenoterol (F) and its conjugate metabolites were determined in healthy female subjects and in pregnant women treated for preterm labour. Sulphate (S) and glucuronide (G) conjugates could be quantified. 2. In the healthy volunteers, AUC of both the metabolites was half that of parent compound (AUC-S/AUC-F: 0.42; 0.14-1.16) (AUC-G/AUC-F: 0.49; 0.18-0.86) during i.v. administration of the drug and was several fold that of parent drug (AUC-S/AUC-F: 116.9; 36.4-353.3, AUC-G/AUC-F: 19.9; 5.1-57.5) after p.o. administration indicating extensive presystemic elimination. 3. In the healthy subjects, the AUC ratio of G:S was 1.1 (0.5-2.6) and 0.16 (0.10-0.27) after i.v. and p.o. administration, respectively, thus indicating that sulphation is the prevailing metabolic pathway in the presystemic elimination. 4. In patients, concentration ratios were used for the analysis. During continuous i.v. treatment, Css-S/Css-F was 3.8 (2.5-4.8) and Css-G/Css-F was 1.5 (0.7-2.1). During p.o. treatment Csstrough S/Csstrough-F was 69.4 (32.1-145.7) and Csstrough-G/Csstrough-F 9.4 (5.6-13.2).(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Frauenklinik und -poliklinik, Klinikum Steglitz Berlin, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Hildebrandt
authors.forename: B
authors.initials: B
authors.lastname: Wagner
authors.forename: K
authors.initials: K
authors.lastname: Preiss-Nowzohour
authors.forename: U
authors.initials: U
authors.lastname: Gundert-Remy
mesh_terms: D000284:Administration, Oral; D000328:Adult; D005260:Female; D005280:Fenoterol / Q000008:administration & dosage / Q000097:blood* / Q000627:therapeutic use*; D005965:Glucuronates / Q000097:blood*; D006801:Humans; D007231:Infant, Newborn; D007262:Infusions, Intravenous; D007752:Obstetric Labor, Premature / Q000097:blood* / Q000188:drug therapy*; D011247:Pregnancy; D013431:Sulfates / Q000097:blood*
chemical_list: D005965:Glucuronates; D013431:Sulfates; D005280:Fenoterol