Antibiotic lock: In vitro stability of vancomycin and four percent 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 (HD). 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 as adjunctive therapy for CRB. The objective of this study was to evaluate the chemical stability of the vancomycin in 4% sodium citrate in HD catheters as an interdialytic lock. Vancomycin was prepared and diluted with sodium citrate 4% and stored in polyvinyl chloride syringes, 2 carbothane dialysis catheters (Hemostar) and 2 dual floating HD catheters (CardioMed). Syringes were stored at 4 degrees C or 23 degrees C and the catheters were stored in an incubator at 37 degrees C for 72 hours. Samples underwent daily chromatographic analysis and the luminal concentration of vancomycn was determined on study days 0, 1, and 3. When vancomycin is reconstituted with normal saline to achieve a concentration of 50 mg/mL, and then further diluted in 4% sodium citrate, to achieve concentrations of either 1 or 3 mg/mL, and then stored at 4 degrees C, room temperature, or 37 degrees C, solutions were observed to retain >92% of the initial concentration for the study period of 3 days. Based on the fastest degradation rate determined with 95% confidence interval, >90% is retained for 6.53 days. We conclude that vancomycin-4% citrate solutions stored in polyvinyl chloride syringes or HD catheters are not significantly affected by temperature or concentration within the 72 hours storage period. Therefore, these solutions can be anticipated to be suitable as a HD interdialytic antibiotic lock in standard HD catheters.

Stability and compatibility of antimicrobial lock solutions

“…The stability and physical compatibility of vancomycin at concentrations ranging from 1 to 10 mg/mL administered with TSC 40 mg/mL was demonstrated through 72 hours. 6,7 Incompatibilities with solutions of vancomycin 20 mg/mL plus TSC 40 mg/mL have been noted. 7 Vancomycin at concentrations of 2 and 5 mg/mL in combination with TSC at concentrations of 22 and 40 mg/mL is reported to be physically and chemically stable for 72 hours.…”

“…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.…”

Compatibility and stability of telavancin and vancomycin in heparin or sodium citrate lock solutions

“…[12][13][14] Also, basic knowledge regarding the compatibility of telavancin in a catheter lock solution may increase the utility of this drug in the treatment of catheterrelated infections. Both vancomycin and telavancin affected PT and aPTT values, the 5-mg/mL concentrations.…”

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

“…The use of ALT in tunneled HD catheters has been shown to have an average success rate of 69% (range: 62%–100%) as an alternative to catheter removal in the treatment of CRB 13–16 . We have also shown that vancomycin‐4% sodium citrate solutions stored in polyvinyl chloride syringes or HD catheters are not significantly affected by temperature or concentration within a 72‐hour storage period 22 . While ATL with vancomycin is acceptable to treat CRB, particularly with higher rates of cephalosporin resistance and increased rates of MRSA bacteremia, there is also an increased rate of Gram‐negative bacteremia seen in HD patients 28,29 .…”

“…Sodium citrate 4% is increasingly used as an inter‐dialytic locking solution 19–21 ; however, there is a paucity of data on its effectiveness, stability, and safety in combination with antibiotics as an ALT 22 . In order to use an antibiotic‐sodium citrate combination as a locking solution to treat infections, the in vitro stability of the combination needs to be assessed.…”