title: Impairment of cefdinir absorption by iron ion.
abstract: The effect of iron ion on the absorption of cefdinir, a new oral cephalosporin derivative, was evaluated in healthy male volunteers in a randomized three-way crossover study. The subjects received 200 mg cefdinir alone, 200 mg cefdinir and two tablets of iron ion concomitantly, and two tablets of iron ion preparation 3 hours after 200 mg cefdinir administration. The area under the concentration curve [AUC(0-12)] of cefdinir with concurrent iron was significantly smaller than that with cefdinir alone (mean +/- SD, 0.78 +/- 0.38 versus 10.3 +/- 1.35 micrograms.hr/ml). While there were no differences in AUC(0-3) between drug alone and drug with iron 3 hours later, the AUC(3-12) with delayed iron was significantly smaller than that of cefdinir alone (4.60 +/- 1.54 versus 8.03 +/- 1.72 micrograms.hr/ml). These findings suggest that the mechanism of interaction between cefdinir and iron ion preparation is the formation of a chelation complex and that this complex probably restricts gastrointestinal absorption.
authors.affiliation: Department of Pharmacy, National Sengokuso Hospital, Osaka, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ueno
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
authors.forename: K
authors.initials: K
authors.lastname: Tsujimura
authors.forename: Y
authors.initials: Y
authors.lastname: Morishima
authors.forename: H
authors.initials: H
authors.lastname: Iwashige
authors.forename: K
authors.initials: K
authors.lastname: Yamazaki
authors.forename: I
authors.initials: I
authors.lastname: Nakata
mesh_terms: D000328:Adult; D002412:Cations; D000077525:Cefdinir; D002511:Cephalosporins / Q000493:pharmacokinetics*; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects*; D007501:Iron / Q000494:pharmacology*; D008297:Male; D012016:Reference Values
chemical_list: D002412:Cations; D002511:Cephalosporins; D000077525:Cefdinir; D007501:Iron