Gentamicin dosing in neonatal patients

Objective: To compare trough and peak serum gentamicin concentrations in ne onatal patients using two dosing regimens. Method: A retrospective audit of gentamicin serum concentrations obtained w ith the current neonatal gentamicin-dosing regimen (regimen 1) was conducte d. Results were then compared with the introduction of a new regimen (regim en 2). Preliminary results necessitated a change to a further dosage schedu le (regimen 3), where data was again collected. Results: For regimen 1,79% of patients achieved satisfactory trough concent rations, 30% achieved satisfactory peak concentrations, and 16% achieved a satisfactory combined trough and peak concentration. For regimen 2,80% of p atients achieved satisfactory trough concentrations, 63% achieved satisfact ory peak concentrations, and 48% achieved a satisfactory combined trough an d peak concentration. For regimen 3,76% of patients achieved satisfactory t rough concentrations, 56% achieved satisfactory peak concentrations, and 45 % achieved a satisfactory combined trough and peak concentration. Conclusion: Regimen 3 shows a marked improvement in serum gentamicin concen trations. However neonates in the 32-38 weeks post-conceptional age group a chieved higher trough and peak serum gentamicin levels than expected. There fore the dosage interval in this group of neonates will be increased from 1 8 hourly to 24 hourly dosing, and regimen reaudited.