Once daily gentamicin dosing in full term neonates.

OBJECTIVE

There is no uniformity in the current recommendations of dosing regimen of gentamicin for neonates. We conducted this study to compare once-daily dosing regimen to the twice-daily dosing regimen for neonates with birth weight of >/=2500 g during the first 7 days of life.

METHODS

Fifty full term infants with birth weight of >/=2500 gm admitted to the neonatal intensive care unit of King Abdul-Aziz University Hospital, Jeddah, Kingdom of Saudi Arabia between November 1999 to October 2000 and received gentamicin at a dose of 2.5 mg/kg every 12 hours (control group) were compared with 50 term infants who received gentamicin at dose of 4 mg/kg every 24 hours during the period of November 2000 until October 2002 (protocol group). Trough and peak serum gentamicin levels (SDL) were measured on all infants.

RESULTS

Peak SDL was 8.4 +/- 1.8 mg/ml in the protocol group, compared to 6.7 +/- 2 mg/ml in the control group (p=0.001). Ninety-eight percent (n=49) of the protocol group, compared to 86% (n=43) of the control group, had peak SDL in therapeutic range. Fifty-eight percent (n=29) of infants in the protocol group, compared to 24% (n=12) of infants in the control group, had peak SDL in higher therapeutic range of 8-12 mg/ml. Six percent (n=3) of the protocol infants, compared to 26% (n=13) of the control infants, had trough SDL >2 mg/ml. Six infants (12%) in the protocol group, versus 20 infants (40%) of the control group, required a dosing adjustment.

CONCLUSION

Gentamicin dose of 4 mg/kg given at 24-hour interval achieved significantly higher peak and safe trough serum concentrations in term infants, compared to the twice-daily regimen of 2.5 mg/kg. We suggest that measurement of gentamicin concentration may be not required when once-daily regimen is prescribed for 72 hours to term infants with suspected sepsis.