Moxifloxacin penetration into human gastrointestinal tissues

Objective: Moxifloxacin is a recently developed fourth-generation methoxyquinolone with abroad spectrum of activity against both Gram-positive and Gram-negative aerobic bacteria and anaerobes. The aim of the present study was to assess the penetration of moxifloxacin into gastrointestinal (GI) mucosal tissues to evaluate its potential role as an antimicrobial drug in bacterial infections of the GI tract. Patients and methods: Twenty-eight patients undergoing GI-tract surgery received 400 mg of moxifloxacin twice pre-operatively [eight patients orally (po) and 20 patients intravenously (iv)], of whom 22 completed the study. Mucosal tissues (three stomach, three small bowel and 16 colon) and serum samples were collected and moxifloxacin concentrations were measured by HPLC. Results: The highest tissue concentrations were detected in the mucosa of the stomach (10.9±5.1 mg/kg), followed by colon mucosa (7.8±7.1 mg/kg after iv; 6.6±3.6 mg/kg after po) and small bowel mucosa (5.4±0.5 mg/kg). The tissue-to-serum ratio of moxifloxacin was 2.0±1.6 in the small bowel mucosa, 5.8± 3.4 and 6.8±3.9 in the colon mucosa after po and iv administration, respectively, and 9.7±5.7 in the stomach mucosa. Conclusion: Moxifloxacin penetrates into and accumulates in the mucosa of the stomach, small bowel and colon. The clinical applicability of moxifloxacin administration for bacterial GI-tract infections should be investigated in controlled trials.