title: Effect of ferrous sulfate and multivitamins with zinc on absorption of ciprofloxacin in normal volunteers.
abstract: Cations such as magnesium and aluminum significantly impair the absorption of ciprofloxacin. Twelve healthy adult male volunteers participated in this four-way crossover study to investigate the effects of ferrous sulfate and multivitamins with zinc on the absorption of ciprofloxacin. Doses of ciprofloxacin (500 mg) were given 7 days apart and after an overnight fast. Dose 1 was administered alone (regimen A). The subjects then received either a ferrous sulfate tablet (325 mg three times a day; regimen B) or a once-daily multivitamin with zinc (regimen C) for 7 days; dose 2 of ciprofloxacin was then given with the last dose of regimen B or C. Subjects were crossed over to the alternate regimen for 7 days, and dose 3 of ciprofloxacin was again administered with the last dose of regimen B or C. After a 7-day washout, dose 4 of ciprofloxacin was given (regimen D). Ciprofloxacin concentrations were determined by high-pressure liquid chromatography. The areas under the concentration-time curve (AUCs) of ciprofloxacin for regimens A and D were not significantly different (14.5 +/- 2.3 versus 15.7 +/- 2.8 micrograms.h/ml, mean +/- standard deviation). The AUCs for regimen B (5.4 +/- 1.7 micrograms.h/ml) and regimen C (11.3 +/- 2.4 micrograms.h/ml) were significantly different from the AUCs for regimens A and D. Peak concentrations of ciprofloxacin with regimen B were below the MIC for 90% of strains of many organisms normally considered susceptible. Ferrous sulfate and multivitamins with zinc significantly impaired the absorption of ciprofloxacin. The effect of ferrous sulfate is likely to be clinically significant; the responsible component of multivitamins with zinc requires additional study.
authors.affiliation: Antibiotic Research Unit, School of Pharmacy, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0581.
authors.forename: R E
authors.initials: RE
authors.lastname: Polk
authors.forename: D P
authors.initials: DP
authors.lastname: Healy
authors.forename: J
authors.initials: J
authors.lastname: Sahai
authors.forename: L
authors.initials: L
authors.lastname: Drwal
authors.forename: E
authors.initials: E
authors.lastname: Racht
mesh_terms: D000328:Adult; D001682:Biological Availability; D002939:Ciprofloxacin / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D004347:Drug Interactions; D005296:Ferrous Compounds / Q000494:pharmacology*; D006207:Half-Life; D006801:Humans; D007408:Intestinal Absorption / Q000187:drug effects; D008297:Male; D014815:Vitamins / Q000494:pharmacology*; D015032:Zinc / Q000494:pharmacology*
chemical_list: D005296:Ferrous Compounds; D014815:Vitamins; C020748:ferrous sulfate; D002939:Ciprofloxacin; D015032:Zinc