title: Effects of aluminum hydroxide and calcium carbonate antacids on the bioavailability of ciprofloxacin.
abstract: This study was designed to determine the effects of an aluminum hydroxide antacid and a calcium carbonate antacid on the bioavailability of ciprofloxacin (Cipro). Cipro (750 mg) was administered orally to 12 healthy volunteers in a three-way randomized crossover design. The three treatments included Cipro alone, four 850-mg calcium carbonate tablets taken 5 min before Cipro, and three 600-mg aluminum hydroxide tablets taken 5 min before Cipro. The relative bioavailability of Cipro when given with calcium carbonate was approximately 60% of the control value. When Cipro was given with aluminum hydroxide, the relative bioavailability was approximately 15%. Urinary recovery of Cipro in the aluminum hydroxide treatment group was approximately one-fourth of that in the calcium carbonate group. Although calcium carbonate decreased absorption to a lesser extent than aluminum hydroxide, these data suggest that antacids containing either aluminum or calcium should not be given concomitantly with Cipro.
authors.affiliation: Department of Pharmacokinetics, Miles Inc., West Haven, Connecticut 06516.
authors.forename: R W
authors.initials: RW
authors.lastname: Frost
authors.forename: K C
authors.initials: KC
authors.lastname: Lasseter
authors.forename: A J
authors.initials: AJ
authors.lastname: Noe
authors.forename: E C
authors.initials: EC
authors.lastname: Shamblen
authors.forename: J T
authors.initials: JT
authors.lastname: Lettieri
mesh_terms: D000328:Adult; D000536:Aluminum Hydroxide / Q000008:administration & dosage / Q000494:pharmacology*; D001682:Biological Availability; D002119:Calcium Carbonate / Q000008:administration & dosage / Q000494:pharmacology*; D002939:Ciprofloxacin / Q000008:administration & dosage / Q000493:pharmacokinetics*; D006801:Humans; D008297:Male
chemical_list: D002939:Ciprofloxacin; D000536:Aluminum Hydroxide; D002119:Calcium Carbonate