VANCOMYCIN STABILITY IN HEPARIN AND TOTAL PARENTERAL-NUTRITION SOLUTIONS - NOVEL-APPROACH TO THERAPY OF CENTRAL VENOUS CATHETER-RELATED INFECTIONS

To facilitate therapy of central venous catheter-related Gram-positive bacterial infection in patients who require total parenteral nutrition (TPN) therapy, we studied the stability of vancomycin in a commonly used TPN solution (V-TPN) at final concentrations of 0.5 mg/mL and 1.0 mg/mL and in heparin (100 U/mL in 0.9% NaCl) at 25-mu-g/mL (V-H). Vancomycin concentrations in V-TPN and V-H after storage at 4-degrees-C over 35 and 14 days, respectively, were stable (within 10% of the prestorage vancomycin concentration). After 14 days at 4-degrees-C heparin activity in V-H solution was 100 +/- 4% of that noted initially. Vancomycin remained stable (100 +/- 6% of the original vancomycin concentration) when the previously refrigerated V-TPN was held for an additional 24 hours at 22-degrees-C. When the previously refrigerated V-H was held for an additional 24 hours at 37-degrees-C, vancomycin concentrations decreased to 78 +/- 9% of the baseline concentrations (p < .001). The stability of vancomycin in this TPN solution allows the daily dose of vancomycin to be mixed with the solution and then infused over 10 hours. As shown with pharmacokinetic modeling, this form of therapy will achieve serum vancomycin concentrations within the therapeutic range throughout a 24-hour period. The relative stability of vancomycin in a heparin line-flush solution allows vancomycin concentration in the lumen of the catheter to be maintained at greater-than-or-equal-to 15-mu-g/mL during the interval between catheter flushing and the subsequent TPN infusion. A simplified method of administering vancomycin to patients receiving concurrent TPN is possible.