title: Oral bioavailability of moxifloxacin after Roux-en-Y gastric bypass surgery.
abstract: OBJECTIVE
  Roux-en-Y gastric bypass surgery is the most commonly performed procedure for the treatment of morbid obesity. This anatomical alteration may affect the absorption and consequently the bioavailability of oral drugs. This study aims to investigate the oral bioavailability of moxifloxacin in 12 healthy volunteers who underwent gastric bypass surgery.
  
  
  METHODS
  In this randomized crossover study, each subject received two single standard doses of 400 mg of moxifloxacin orally or intravenously administered on two occasions separated by a washout period of 1 week. Serial venous blood samples were drawn up to 72 h after dosing and moxifloxacin plasma levels were measured by a validated HPLC method with fluorescence detection. [clinicaltrials.gov database (identifier: NCT01130922).]
  
  
  RESULTS
  After oral dosing, moxifloxacin plasma concentrations reached a maximum (C(max)) of 3.38 ± 1.41 mg/L after 1.75 h (0.75-4.00). After intravenous dosing, C(max) and T(max) were 4.53 ± 1.43 mg/L and 1.03 h (0.75-2.50), respectively. The mean areas under the plasma concentration time curve extrapolated to infinity (AUC(∞)) were 46.2 ± 1.4 mg · h/L after oral dosing and 52.3 ± 1.3 mg · h/L after intravenous dosing, resulting in a mean oral bioavailability of 88.32% [90% confidence interval (CI) 85.64%-91.08%].
  
  
  CONCLUSIONS
  This study confirms that exposure to moxifloxacin is equivalent for oral and intravenous administration of 400 mg dosages in healthy volunteers who underwent gastric bypass surgery. But these exposures were more than 50% higher than those described for subjects without gastric bypass. This may suggest a higher enterohepatic recirculation of moxifloxacin after gastric bypass.
authors: Laboratory of Medical Biochemistry and Clinical Analysis, Faculty of Pharmaceutical Sciences, Ghent University, Harelbekestraat 72, B-9000 Gent, Belgium. julie.desmet@ugent.be
authors: Julie
authors: J
authors: De Smet
authors: Pieter
authors: P
authors: Colin
authors: Peter
authors: P
authors: De Paepe
authors: Johannes
authors: J
authors: Ruige
authors: Hélène
authors: H
authors: Batens
authors: Yves
authors: Y
authors: Van Nieuwenhove
authors: Dirk
authors: D
authors: Vogelaers
authors: Stijn
authors: S
authors: Blot
authors: Jan
authors: J
authors: Van Bocxlaer
authors: Luc M
authors: LM
authors: Van Bortel
authors: Koen
authors: K
authors: Boussery
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D001372:Aza Compounds / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D001682:Biological Availability; D018592:Cross-Over Studies; D005260:Female; D024841:Fluoroquinolones; D015390:Gastric Bypass; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D008875:Middle Aged; D000077266:Moxifloxacin; D009765:Obesity / Q000601:surgery; D011804:Quinolines / Q000008:administration & dosage* / Q000493:pharmacokinetics*
chemical_list: D000900:Anti-Bacterial Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D011804:Quinolines; D000077266:Moxifloxacin