title: Influence of an antacid containing aluminum and magnesium on the pharmacokinetics of cefixime.
abstract: Interaction studies in dogs have indicated that antacids significantly decrease the oral bioavailability of cefixime. Twelve healthy adult male volunteers participated in a randomized, four-way crossover trial to evaluate the influence of an aluminum-magnesium antacid (Maalox; 20 ml) on the pharmacokinetics of cefixime (400 mg). Regimens were (i) cefixime alone; (ii) cefixime simultaneous with antacid; (iii) cefixime 2 h before antacid; and (iv) cefixime 2 h after antacid. Serial blood and urine samples were collected over a 24-h period following each dose of cefixime. There was a 1-week washout interval between regimens. Cefixime concentrations in serum and urine were analyzed by high-performance liquid chromatography. Maximum cefixime concentrations in serum for regimens i through iv were (mean +/- standard deviation) 4.9 +/- 1.4, 5.7 +/- 1.3, 5.1 +/- 1.0, and 5.5 +/- 1.5 micrograms/ml, respectively. Corresponding values for area under the serum concentration-time curve extrapolated to infinity were 38.3 +/- 14.5, 42.8 +/- 13.9, 38.5 +/- 9.8, and 41.6 +/- 16.7 micrograms.h/ml. There was a trend toward increased concentrations in serum and area under the curve of cefixime when it was administered concomitantly with antacid; however, these differences were not statistically significant (P greater than 0.05; analysis of variance). We conclude that single-dose administration of an aluminum-magnesium antacid does not significantly decrease the oral bioavailability of cefixime.
authors.affiliation: Department of Pharmacy and Pharmaceutics, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0581.
authors.forename: D P
authors.initials: DP
authors.lastname: Healy
authors.forename: J V
authors.initials: JV
authors.lastname: Sahai
authors.forename: L P
authors.initials: LP
authors.lastname: Sterling
authors.forename: E M
authors.initials: EM
authors.lastname: Racht
mesh_terms: D000328:Adult; D000536:Aluminum Hydroxide / Q000494:pharmacology*; D000863:Antacids / Q000494:pharmacology*; D001682:Biological Availability; D020682:Cefixime; D002439:Cefotaxime / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D004338:Drug Combinations / Q000494:pharmacology; D004347:Drug Interactions; D006207:Half-Life; D006801:Humans; D008274:Magnesium / Q000494:pharmacology*; D008276:Magnesium Hydroxide / Q000494:pharmacology*; D008297:Male
chemical_list: D000863:Antacids; D004338:Drug Combinations; C013591:aluminum hydroxide, magnesium hydroxide, drug combination; D000536:Aluminum Hydroxide; D020682:Cefixime; D008274:Magnesium; D002439:Cefotaxime; D008276:Magnesium Hydroxide