160. Evaluation of Vancomycin Dosing in Infants Less than 1200 Grams and Greater than 30 Days Old
Session: Poster Abstract Session: Antimicrobial Use in Children
Thursday, October 3, 2013
Room: The Moscone Center: Poster Hall C
Posters
  • ACHvanco-infant-PosterpngFinal(1).pdf (495.5 kB)
  • Background: Pre-term infants are at high risk for nosocomial infections with gram positive pathogens. Vancomycin is often used for empiric antibiotic therapy in this patient population. The neonatal intensive care unit guidelines (NICU) at Advocate Children’s Hospital (ACH) were derived from Pediatric and Neonatal Dosage Handbook. For infants weighing less than 1200 grams the recommended dose is weight-based and the dosing interval is constant regardless of postnatal age (PNA). The rapid maturation in postnatal renal function makes vancomycin dosing challenging in this subset of NICU patients. The literature evaluating vancomycin dosing in the NICU is limited and provides conflicting dose recommendations. Most studies were designed to achieve vancomycin serum trough concentrations of 5-15 mg/L. In adults, the recommended vancomycin trough has recently increased from 5-15 mg/L to 10-20mg/L due to trends of increased Staphylococcus aureus resistance. The ACH NICU has adopted this higher trough goal for vancomycin. The purpose of this study was to assess whether vancomycin trough concentrations of 10-20 mg/mL were obtained using once daily dosing as recommended in infants less than 1200 grams and greater than 30 days PNA.

    Methods: A retrospective cohort of patients admitted to the ACH NICU from September 2007 to November 2012. Vancomycin trough concentrations, gestational age, birth weight, PNA, body weight, and serum creatinine were collected.

    Results: Forty-four vancomycin trough levels were evaluated in 35 patients meeting study criteria.  Only four out of 22 levels (18.2%) in infants treated with a 24-hour dosing interval were therapeutic.  With a more frequent dosing interval 13 out of 22 (59.1%) levels (p=0.002) fell within target trough range.  Two supratherapeutic levels occurred in infants with more frequent dosing.  One subject had a greater than 50% increase in serum creatinine not attributable to vancomycin use. Audiometric evaluations not available to assess ototoxicity. 

    Conclusion: Once daily vancomycin dosing achieved subtherapeutic levels in infants 30 days PNA with body weight less than 1200 grams. Dosing frequencies of every 8 or 12 hours were more likely to achieve target vancomycin trough levels of 10-20 mg/L in this population

    Cassandra Vandevoorde, PharmD and Kelly Kopec, PharmD, Pharmacy, Advocate Lutheran General Hospital, Park Ridge, IL

    Disclosures:

    C. Vandevoorde, None

    K. Kopec, None

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