Impairment of cefdinir absorption by iron ion.

Author(s): Ueno K, Tanaka K, Tsujimura K, Morishima Y, Iwashige H, Yamazaki K, Nakata I

Affiliation(s): Department of Pharmacy, National Sengokuso Hospital, Osaka, Japan.

Publication date & source: 1993-11, Clin Pharmacol Ther., 54(5):473-5.

Publication type: Clinical Trial; Randomized Controlled Trial

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.