What is known about Vancomycin dosing in neonates?
Staphylococcus epidermis, including methicillin-resistant strains, are inhibited by vancomycin concentrations of 1-4 µg/ml. 
Staphylococcus pyogenes, Streptococcus pneumonia, and Streptococcus viridans are susceptible to 2 µg/ml vancomycin. 
Bacillus spp. are inhibited by 2 µg/ml, Corynebacterium spp. by 0.04-3.1 µg/ml and Clostridium spp. by 0.39-6 µg/ml vancomycin. 
Peak and trough concentrations of vancomycin should be 40 μg/ml and 10 μg/ml, respectively, to both be effective and avoid oto- or nephrotoxicity in adults. There is no ideal pattern of vancomycin dosing; vancomycin dosages must be individualized. Because vancomycin activity is primarily time-dependent, the 24-h area under the curve (AUC0-24h) divided by the minimum inhibitor concentration (MIC) value (AUC0-24h/MIC) is a better predictor of efficacy. In adults with MIC values less than 1 μg/ml, trough concentrations greater than 10 µg/ml result in AUC0-24h/MIC values 400
Compared with adults, neonates have a higher extracellular fluid volume and a limited renal elimination capacity resulting in different pharmacokinetics subject to maturation stage.  Infants weighing less than 1,000 gm had significantly larger volumes of drug distribution and consequently longer drug half-lives than larger premature infants, regardless of postconceptual or actual age. These differences alter the vancomycin dosing recommendations in these two groups of premature infants.
Vancomycin-associated nephrotoxicity is rare in neonates, even with serum peak concentrations 40 microg/mL. Vancomycin is associated with ototoxicity.
There is no consensus on vancomycin dosing in newborns and young infants, which leads to significant variation in vancomycin dosing regimens and TDM guidance across neonatal units. The development of standardized, evidence-based protocols should be prioritized.