Evaluation of vancomycin target trough attainment with published dosing regimens in the neonatal intensive care unit...

Study aims to evaluate whether vancomycin dosing from published dosing algorithms correlate with the attainment of target troughs of 10 to 20 mg/L.

NICU patients who received minimum three doses of vancomycin and had a trough level met inclusion criteria. Dosing information was retrospectively evaluated to determine which published dosing regimen was followed. Dosing algorithms used were matched to NeoFax/Harriet Lane, renal-function directed dosing, and weight-directed dosing, in which the latter two can be found in Pediatric and Neonatal Lexi-Drugs. Primary outcome was percentage of troughs within therapeutic (10 to 20 mg/L) and subtherapeutic (less than 10 mg/L) levels.

Of 97 troughs evaluated, NeoFax/Harriet Lane accounted for 86.6%, renal-function directed accounted for 5.1%, and weight-directed dosing accounted for 18.5% of dosing algorithms. NeoFax/Harriet Lane, renal-function directed, and weight-directed dosing attained therapeutic levels between 10 to 20 mg/L at a rate of 60.7%, 60%, and 50% of the time, respectively. With respect to initiation of therapy, a higher dose of 15 mg/kg versus 10 mg/kg attained therapeutic levels (p < 0.001; OR 11.22; 95% CI, 3.96 to 31.81), while a serum creatinine value below 0.5 mg/dL attained subtherapeutic levels (p = 0.028; OR 0.068; 95% CI, 0.006 to 0.74).

NeoFax, Harriet Lane, and renal-directed dosing from Pediatric and Neonatal Lexi-Drugs achieved target troughs within the 10 to 20 mg/L range more often than weight-directed dosing from Pediatric and Neonatal Lexi-Drugs. Initiating therapy at a higher dose and patient serum creatinine value above 0.5 mg/dL were factors significantly associated with a 10 to 20 mg/L range.