Open AccessInhibition of enoxacin absorption by antacids or ranitidine
Author(s) -
Thaddeus H. Grasela,
Jerome J. Schentag,
Allen J. Sedman,
John H. Wilton,
D. Thomas,
Rebecca Schultz,
M. E. Lebsack,
Arlyn W. Kinkel
Publication year - 1989
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.33.5.615
Subject(s) - enoxacin , antacid , bioavailability , ranitidine , pharmacology , drug interaction , chemistry , oral administration , crossover study , pharmacokinetics , absorption (acoustics) , medicine , norfloxacin , antibiotics , biochemistry , physics , alternative medicine , pathology , ciprofloxacin , acoustics , placebo
Ten normal volunteers participated in a randomized, five-way crossover study to determine the effect of concurrent enoxacin and antacid or ranitidine administration on enoxacin absorption. The bioavailability of a single oral 400-mg enoxacin dose was significantly decreased, by 73 and 49%, when Maalox TC was administered 0.5 and 2 h before enoxacin, respectively. Enoxacin bioavailability was not significantly altered when the antacid was given 8 h before or 2 h after enoxacin administration. Ranitidine, administered intravenously 2 h before enoxacin, also significantly decreased enoxacin bioavailability, by 40%. The correlation between the proximity of antacid administration and the magnitude of the decrease in enoxacin bioavailability supports complexation as the mechanism of the antacid-enoxacin interaction. However, reduction of enoxacin bioavailability by ranitidine suggests that elevated gastric pH may also play a role in the antacid-enoxacin drug-drug interaction.