title: The role of monitoring gentamicin levels in patients with gram-negative peritoneal dialysis-associated peritonitis.
abstract: BACKGROUND
  There is limited available evidence regarding the role of monitoring serum gentamicin concentrations in peritoneal dialysis (PD) patients receiving this antimicrobial agent in gram-negative PD-associated peritonitis.
  
  
  METHODS
  Using data collected in all patients receiving PD at a single center who experienced a gram-negative peritonitis episode between 1 January 2005 and 31 December 2011, we investigated the relationship between measured serum gentamicin levels on day 2 following initial empiric antibiotic therapy and subsequent clinical outcomes of confirmed gram-negative peritonitis.
  
  
  RESULTS
  Serum gentamicin levels were performed on day 2 in 51 (77%) of 66 first gram-negative peritonitis episodes. Average serum gentamicin levels on day 2 were 1.83 ± 0.84 mg/L with levels exceeding 2 mg/L in 22 (43%) cases. The overall cure rate was 64%. No cases of ototoxicity were observed. Day-2 gentamicin levels were not significantly different between patients who did and did not have a complication or cure. Using multivariable logistic regression analysis, failure to cure peritonitis was not associated with either day-2 gentamicin level (adjusted odds ratio (OR) 0.96, 95% confidence interval (CI) 0.25 - 3.73) or continuation of gentamicin therapy beyond day 2 (OR 0.28, 0.02 - 3.56). The only exception was polymicrobial peritonitis, where day-2 gentamicin levels were significantly higher in episodes that were cured (2.06 ± 0.41 vs 1.29 ± 0.71, p = 0.01). In 17 (26%) patients receiving extended gentamicin therapy, day-5 gentamicin levels were not significantly related to peritonitis cure.
  
  
  CONCLUSIONS
  Day-2 gentamicin levels did not predict gentamicin-related harm or efficacy during short-course gentamicin therapy for gram-negative PD-related peritonitis, except in cases of polymicrobial peritonitis, where higher levels were associated with cure.
authors.affiliation: Division of Nephrology,1 Peking University Third Hospital, Beijing, China;
authors.forename: Wen
authors.initials: W
authors.lastname: Tang
authors.forename: Yeoungjee
authors.initials: Y
authors.lastname: Cho
authors.forename: Carmel M
authors.initials: CM
authors.lastname: Hawley
authors.forename: Sunil V
authors.initials: SV
authors.lastname: Badve
authors.forename: David W
authors.initials: DW
authors.lastname: Johnson
mesh_terms: D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000493:pharmacokinetics*; D015331:Cohort Studies; D016903:Drug Monitoring; D005260:Female; D005839:Gentamicins / Q000493:pharmacokinetics*; D006090:Gram-Negative Bacteria / Q000302:isolation & purification; D016905:Gram-Negative Bacterial Infections / Q000378:metabolism* / Q000382:microbiology; D006801:Humans; D007676:Kidney Failure, Chronic / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010530:Peritoneal Dialysis; D010538:Peritonitis / Q000378:metabolism* / Q000382:microbiology; D011446:Prospective Studies; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D005839:Gentamicins
keywords: Aminoglycosides; chronic outcomes; gentamicin; kidney failure; peritoneal dialysis; peritonitis; therapeutic drug monitoring