title: The effect of the molecular adsorbent recirculating system on moxifloxacin and meropenem plasma levels.
abstract: BACKGROUND
  Adequate plasma antibiotic concentrations are necessary for effective elimination of invading microorganism; however, extracorporeal organ support systems are well known to alter plasma concentrations of antibiotics, requiring dose adjustments to achieve effective minimal inhibitory concentrations in the patient's blood.
  
  
  METHODS
  A mock molecular adsorbent recirculating system (MARS) circuit was set using 5000 ml of bovine heparinized whole blood to simulate an 8-h MARS treatment session. After the loading dose of 400 mg of moxifloxacin or 2 g of meropenem had been added, blood was drawn from the different parts of the MARS circuit at various time points and analyzed by high-performance liquid chromatography. The experiments were performed in triplicate. Additionally, meropenem concentrations were determined in the plasma of one patient treated with MARS suffering from acute liver failure due to an idiosyncratic reaction to immunosuppressive medication.
  
  
  RESULTS
  In our single-compartment model, a significant decrease in the quasi-systemic concentration of moxifloxacin and meropenem could be detected as early as 15 min after the commencing of the MARS circuit. Moreover, within 60 min the moxifloxacin and meropenem concentrations were less than 50% of the initial value. The activated charcoal removed the majority of moxifloxacin and meropenem in the albumin circuit. In our patient, the meropenem concentrations in the return line after MARS were constantly lower than in the access line, indicating a likely removal of meropenem through MARS.
  
  
  CONCLUSIONS
  Our data provide evidence that moxifloxacin and meropenem are effectively removed from the patient's blood by MARS, leading to low plasma levels. Dose adjustments of both antibiotic compounds may be required.
authors.affiliation: Department of Anesthesiology, General Intensive Care and Pain Medicine, Medical University of Vienna, Vienna, Austria. georg.roth@meduniwien.ac.at
authors.forename: G A
authors.initials: GA
authors.lastname: Roth
authors.forename: W
authors.initials: W
authors.lastname: Sipos
authors.forename: M
authors.initials: M
authors.lastname: Höferl
authors.forename: M
authors.initials: M
authors.lastname: Böhmdorfer
authors.forename: E M
authors.initials: EM
authors.lastname: Schmidt
authors.forename: H
authors.initials: H
authors.lastname: Hetz
authors.forename: K
authors.initials: K
authors.lastname: Schebesta
authors.forename: D
authors.initials: D
authors.lastname: Klaus
authors.forename: M
authors.initials: M
authors.lastname: Motal
authors.forename: W
authors.initials: W
authors.lastname: Jäger
authors.forename: C G
authors.initials: CG
authors.lastname: Krenn
mesh_terms: D000900:Anti-Bacterial Agents / Q000097:blood*; D001372:Aza Compounds / Q000097:blood*; D024841:Fluoroquinolones; D006801:Humans; D000077731:Meropenem; D000077266:Moxifloxacin; D011804:Quinolines / Q000097:blood*; D016060:Sorption Detoxification / Q000379:methods*; D013845:Thienamycins / Q000097:blood*
chemical_list: D000900:Anti-Bacterial Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D011804:Quinolines; D013845:Thienamycins; D000077731:Meropenem; D000077266:Moxifloxacin