Article Text

  1. S S Krishnamoorthy1,
  2. S Garg1,
  3. S Janakiraman1,
  4. C Harikumar1,
  5. J Jani1,
  6. S Gupta1
  1. 1Neonatal Unit, Department of Child Health, University Hospital of North Tees, Stockton on Tees, Cleveland, UK


Background Gentamicin along with penicillin is considered the gold standard for empiric first-line therapy of neonatal infections. Various dosing regimens exist. Whereas peak serum levels correlate with efficacy, trough levels denote toxicity.

Aims To determine trough levels of gentamicin in neonates in order to assess the safety of the recommended 5 mg/kg per 24 h regimen widely used in the UK.

Methods Pre-third dose gentamicin trough levels were obtained in all neonates receiving gentamicin admitted to a special care baby unit over a one-year period. A further pilot study was done on preterm babies <32 weeks’ gestation. Glomerular filtration rate (GFR) was calculated using the equation: k × length × 88.4/serum creatinine.

Results During the study period 106 neonates received gentamicin. 39 babies had trough levels exceeding 2 mg/dl. 30/39(77%) were born preterm. 25% of term neonates (9/36) and 43% (30/70) of preterm babies had high levels. At ⩽32 weeks’ gestation 50% had high values. A further pilot study on extremely preterm babies revealed 100% elevated levels at <28 weeks’ gestation and 71.5% elevated at 28–32 weeks’ gestation. Whereas 85% of neonates with a calculated GFR <25 ml/min per 1.73 m2 had abnormally high levels, none of the babies with a GFR over 25 had abnormal levels.

Conclusion A dosage of 5 mg/kg per day is potentially toxic for neonatal gentamicin therapy and we suggest a lower dosage schedule at longer intervals, taking into account gestational age and renal function.

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