title: Relation between amoxicillin concentration in sputum of COPD patients and length of hospitalization.
abstract: Amoxicillin is a widely used antibiotic in COPD. Little is known about the transfer of amoxicillin into sputum of COPD patients. The objective was to investigate the relationship between the concentration of amoxicillin in sputum in hospitalized COPD patients and length of hospitalization. To be effective against bacterial pathogens, the amoxicillin concentration in target tissues should be higher than the Minimal Inhibiting Concentration (MIC) of 2 mg/l. Therefore, this was also used as the cut-off value for the amoxicillin concentration in sputum, as a marker for lung tissue concentration. Fifty-two COPD in-patients with an exacerbation, treated with amoxicillin clavulanic acid, were included in this cohort study. Of these patients 7 also had pneumonia. Patients were divided in patients with an amoxicillin sputum concentration ≥ 2 mg/l and < 2 mg/l. Furthermore, inflammation markers in sputum and serum and clinical parameters were obtained. Of the 33 patients with usable sputum, 11 had a concentration in sputum ≥ 2 mg/l. The mean length of hospitalization for patients with concentrations below the MIC90 to common respiratory pathogens was 11.0 days, while for patients with concentrations at or above the MIC90 this was 7.0 days (p = 0.005). COPD patients admitted for an acute exacerbation of COPD, with a sputum concentration of amoxicillin ≥ 2 mg/l had a markedly reduced length of hospitalization compared to patients with a concentration < 2 mg/l. It is worthwhile testing whether individualized treatment based on sputum amoxicillin concentrations of patients during hospitalization for acute exacerbations can effectively reduce hospital stay.
authors.affiliation: Department of Pulmonary Medicine, Medisch Spectrum Twente, Enschede, the Netherlands. m.brusse-keizer@mst.nl
authors.forename: Marjolein
authors.initials: M
authors.lastname: Brusse-Keizer
authors.forename: Leonore
authors.initials: L
authors.lastname: ten Bokum
authors.forename: Kris
authors.initials: K
authors.lastname: Movig
authors.forename: Paul
authors.initials: P
authors.lastname: van der Valk
authors.forename: Huib
authors.initials: H
authors.lastname: Kerstjens
authors.forename: Job
authors.initials: J
authors.lastname: van der Palen
authors.forename: Ron
authors.initials: R
authors.lastname: Hendrix
mesh_terms: D000368:Aged; D000658:Amoxicillin / Q000032:analysis* / Q000627:therapeutic use; D019980:Amoxicillin-Potassium Clavulanate Combination / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000032:analysis* / Q000627:therapeutic use; D018450:Disease Progression; D005260:Female; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000188:drug therapy; D013183:Sputum / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D019980:Amoxicillin-Potassium Clavulanate Combination; D000658:Amoxicillin