Giving vancomycin as a continuous infusion
- Newcastle Neonatal Service, Royal Victoria Infirmary, Newcastle Hospitals NHS Trust, Newcastle upon Tyne, UK
- Dr Nicholas D Embleton, Newcastle Neonatal Service, Royal Victoria Infirmary, Newcastle Hospitals NHS Trust, Newcastle upon Tyne NE1 4LP, UK;
- Accepted 30 January 2009
The recent paper advocating “a new dosage schedule” for giving vancomycin in early infancy1 confirms what others have long said is usually the most appropriate total daily dose for babies of less than 34 weeks’ gestation who are more than a week old, and focuses on the time-dependent rather than the concentration-dependent mode of vancomycin killing. Continuous infusion may prevent the risks of high peaks and low troughs seen with intermittent dosage. However, we disagree with the suggestion that a first loading dose is not necessary. The earlier paper that recommended this same strategy 10 years ago2 correctly said, “Vancomycin half-life is usually between 3 and 10 h in neonates. The time to reach steady state, which is 4 to 5 times the half-life, might thus be expected to be around 48 h in this specific population. Such a time to reach early bactericidal efficacy appeared too long in cases of septicaemia. For this reason, we decided to inject a 7 mg kg−1 loading dose”.
The one trial to look at the relative merits of intermittent and continuous infusion, which found no evidence that continuous infusions were better than intermittent infusions in adults,3 also used a loading dose. The reference used to justify the assertion that a loading dose is not necessary was data presented by poster stating that therapeutic levels were reached within 12 h in much older children,4 but this overlooks the fact that the half-life is much shorter in 5–10-year-old children than it is in the first few weeks of life and, indeed, also rather shorter than it is adult life.
Failure to give a loading dose where there is clear evidence of septicaemia will leave any young baby dangerously under-treated for many hours. There are reasons for thinking that a continuous infusion may be a useful option when treating meningitis, as the discussion of these issues in the Neonatal Formulary web site argues,5 but a loading dose is required.