Effect of gastric acidity on enoxacin absorption

M. E. Lebsack, David E. Nix, Bruce Ryerson, Roger D. Toothaker, Linda Welage, Allyn M. Norman, Jerome J. Schentag, Allen J. Sedman

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24 Scopus citations


The effect of gastric acidity on the oral absorption of the quinolone antibiotic enoxacin was evaluated in 12 healthy volunteers. In a randomized, crossover design, single 400 mg oral enoxacin doses were administered on four occasions: alone, after 50 mg intravenous ranitidine, after 2 μg/kg subcutaneous pentagastrin, and after combined ranitidine and pentagastrin treatment. Gastric pH was monitored by radiotelemetry capsule for 4 hours after enoxacin administration. Ranitidine pretreatment reduced enoxacin oral-bioavailability by an average of 26%. This effect was abolished when pentagastrin was used to maintain low gastric pH. Thus the ranitidine-induced decrease in enoxacin oral bioavailability probably results from a decrease in gastric acidity rather than from an interaction with ranitidine itself.

Original languageEnglish (US)
Pages (from-to)252-256
Number of pages5
JournalClinical Pharmacology and Therapeutics
Issue number3
Publication statusPublished - Sep 1992
Externally publishedYes


ASJC Scopus subject areas

  • Pharmacology

Cite this

Lebsack, M. E., Nix, D. E., Ryerson, B., Toothaker, R. D., Welage, L., Norman, A. M., ... Sedman, A. J. (1992). Effect of gastric acidity on enoxacin absorption. Clinical Pharmacology and Therapeutics, 52(3), 252-256.