Antibiotic lock: In vitro stability of gentamicin and sodium citrate stored in dialysis catheters at 37 °C

Abstract

Catheter-related bacteremia (CRB) is a major cause of morbidity and mortality especially among patients receiving hemodialysis. Antibiotic lock therapy represents a promising technique in the treatment of CRB. Several studies have evaluated antibiotics in combination with heparin as an interdialytic locking solution for prophylaxis of CRB. The objective of this study was to evaluate the stability of gentamicin and sodium citrate in hemodialysis catheters as an interdialytic lock. Solutions containing gentamicin 2.5 mg/mL and sodium citrate 40 mg/mL (4%) were prepared individually and in combination. The solutions were instilled into dialysis catheters and stored at 37 degrees C for 96 h. Samples were withdrawn randomly from catheter lumens at 24-hour intervals for 4 days and stored at -20 degrees C until analysis. The samples were analyzed with validated, stability-indicating HPLC assays. The luminal concentration of gentamicin 2.5 mg/mL, sodium citrate 40 mg/mL (4%), and the combination was determined on study days 0, 1, 2, 3, and 4. When gentamicin was combined with sodium citrate and stored at 37 degrees C in dialysis catheters, the solution showed no decrease in either the gentamicin or the sodium citrate concentrations over the 96-hour study period. The percent of the original concentration at 96 h was 102.4+/-1.03 for gentamicin and 102.9+/-1.25 for citrate (P=0.5556). The combination of gentamicin 2.5 mg/mL and sodium citrate 40 mg/mL (4%) can be retained in hemodialysis catheters for at least 96 h at 37 degrees C with no evidence of degradation.

Stability and compatibility of antimicrobial lock solutions

“…26 Gentamicin 2.5 mg/mL with TSC 40 mg/mL remains stable, with no change in gentamicin concentration, for at least 112 days at room temperature. 5,7,8 Solutions of gentamicin 3 mg/mL and daptomycin 1 mg/mL with or without TSC 28 mg/ mL maintained more than 90% of the original drug concentrations for 48 hours. 9 Gentamicin 5 mg/mL has also been studied with EDTA 30 mg/mL, and visual compatibility for at least 72 hours at 25 or 37 °C was demonstrated.…”

“…1 Heparin is the most commonly used anticoagulant additive in ALT, but other compounds, including trisodium citrate (TSC) and ethylenediaminetetraacetic acid (EDTA), which work synergistically with most antiinfectives, as well as thrombolytics, have been studied. [5][6][7][8][9][10][11] Because of the increase in ALT utilization in both inpatient and outpatient settings and the continuing emergence of novel lock solutions, it is imperative that concise and validated stability and compatibility data are available to practitioners. This review details the available stability and compatibility data from evaluations of antimicrobial lock solutions used in combination with anticoagulants or other additives and provides recommendations for clinical application.…”

Physical Compatibility, Antimicrobial Activity, and Stability of Cefazolin Combined with Gentamicin or Ethanol in Sodium Citrate as a Catheter Lock Solution

“…[ 8 ] A similar compatibility behavior was reported by Battistella et al . when gentamicin (2.5 mg/ml) was combined with sodium citrate solution (4%) and stored at 37°C in dialysis catheters over 96 h.[ 20 ]…”

Antimicrobial lock solutions for implantable central venous devices: stability of vancomycin solutions

“…También se han empleado agentes quelantes como el ácido etilen diamin tetra acético (EDTA) y el citrato trisódico (TSC) en soluciones de sellado, basándose en que cationes metálicos juegan un papel importante en el crecimiento de las bacterias (16,33). Un panel de expertos para dispositivos de acceso venoso desarrolló un consenso sobre los criterios basados en la evidencia para la elección y el uso clínico de la solución de sellado más adecuada para los CVC (excluyendo los catéteres de diálisis) y, entre sus conclusiones, recoge que la solución de sellado más adecuada debe incluir citrato ya que tiene actividad tanto antibacteriana como antibiofilm (34)(35)(36)(37)(38)(39)(40).…”