title: Nizatidine, an H2-blocker. Its metabolism and disposition in man.
abstract: The disposition of a single oral dose of about 150 mg of nizatidine, an H2-blocker, was studied in five men. Plasma levels of both parent drug and radioactivity peaked in 1-3 hr. Nizatidine accounted for about 60% of the plasma radioactivity. The t1/2 of nizatidine was 1.6 hr. About 35% of nizatidine became bound to plasma proteins in vitro, particularly to alpha-1-glycoprotein. Warfarin, acetaminophen, phenobarbital, propantheline, diazepam, and propranolol did not notably affect the amount of nizatidine bound. Two to 3 times more radioactivity was in plasma than in blood cells or saliva. Greater than 90% of the dose of nizatidine was excreted in urine, probably by glomerular filtration and active tubular secretion. Nizatidine accounted for about 65% of the urinary radioactivity. The major metabolite of nizatidine was N2-monodesmethylnizatidine; it represented about 7% of the nizatidine dosage. Another metabolite, constituting about 5% of the dose, is proposed to be nizatidine N2-oxide. Nizatidine sulfoxide also may be a minor metabolite of nizatidine.
authors.forename: M P
authors.initials: MP
authors.lastname: Knadler
authors.forename: R F
authors.initials: RF
authors.lastname: Bergstrom
authors.forename: J T
authors.initials: JT
authors.lastname: Callaghan
authors.forename: A
authors.initials: A
authors.lastname: Rubin
mesh_terms: D000328:Adult; D001798:Blood Proteins / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D002927:Cimetidine / Q000378:metabolism / Q000652:urine; D006635:Histamine H2 Antagonists / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism* / Q000652:urine; D006801:Humans; D008297:Male; D008875:Middle Aged; D016567:Nizatidine; D011485:Protein Binding; D011899:Ranitidine / Q000378:metabolism / Q000652:urine; D012463:Saliva / Q000032:analysis; D013844:Thiazoles / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism* / Q000652:urine
chemical_list: D001798:Blood Proteins; D006635:Histamine H2 Antagonists; D013844:Thiazoles; D002927:Cimetidine; D011899:Ranitidine; D016567:Nizatidine