Effects of magnesium-aluminum hydroxide antacid on absorption of rufloxacin

Abstract

The present study was designed to determine the effects of an antacid suspension containing magnesium hydroxide and aluminum hydroxide (30 ml of Maalox) on the oral bioavailability of rufloxacin (400 mg). Rufloxacin was administered oraly to 12 healthy volunteers according to a randomized, balanced, crossover design. Three treatments were administered to each subject, with a 10-day washout period between treatments; the treatments included rufloxacin alone, rufloxacin taken 5 min after antacid, and rufloxacin taken 4 h before antacid. Administration of antacid within 5 min before the administration of rufloxacin resulted in a substantial decrease in rufloxacin absorption, with a mean percent relative bioavailability compared with control values of 64% (range, 42 to 77%). Administration of antacid 4 h after the administration of rufloxacin slightly affected the absorption of the quinolone (mean relative bioavailablity, 87%; range, 51 to 110%Y). Antacids that contain magnesium and aluminum salts reduce the absorption of rufloxacin. The extent of this interaction depends on the time that elapses between administration of the two drugs.

Roles of divalent cations and pH in mechanism of action of nitroxoline against Escherichia coli strains

“…On the other hand, such a complexation between NIT and metal ions would also limit the absorption of this compound by the human gastrointestinal tract because of the formation of insoluble chelates. Indeed, a reduced bioavailability has especially been shown for quinolones in the presence of magnesium, iron, and aluminum, which are commonly found in antacids (17,29,48).…”

“…The antagonistic effects of divalent cations (Mg ) and quinolones (1,6,12,39), tetracyclines (41), aminoglycosides (6,29), and other agents (28,41). Because urine contains appreciable quantities of inorganic ions (2,16), it is possible that the formation of chelates between NIT and metal ions may affect in vivo the efficacy of this drug.…”

“…Inasmuch as there have been many reports in the literature indicating that different metal ions affect the antimicrobial activities (1, 6, 15, 21, 39), bacterial uptake (12), and bioavailabilities (17,29,48) of numerous antibiotics, we were interested in studying how some metal ions affect the activity of NIT against E. coli strains.…”

Pharmacokinetics of Gatifloxacin and Interaction with an Antacid Containing Aluminum and Magnesium

“…Yamanaka-Yuen and Gantu (27) showed a reduction of bioavailability of norfloxacin by 2 and 77%, if aluminum magnesium hydroxide was given 5 min before or 2 h after norfloxacin. Lazzaroni et al (11) described the interaction between rufloxacin and aluminum magnesium hydroxide. They found a substantial decrease of the relative bioavailability by 36% after administration of the antacid within 5 min before the intake of rufloxacin (11).…”

“…Lazzaroni et al (11) described the interaction between rufloxacin and aluminum magnesium hydroxide. They found a substantial decrease of the relative bioavailability by 36% after administration of the antacid within 5 min before the intake of rufloxacin (11). In a previous study involving trovafloxacin (23), the AUC values were significantly decreased, by 66 and 28%, when administration of aluminum magnesium hydroxide was 30 min before or 2 h after trovafloxacin.…”