Evaluation of bayesian forecasting for individualized gentamicin dosage in infants weighing 1000 g or less
K. Lui, S. M. Bryson, D. B. Irwin and S. Costello
Department of Pediatrics, Hospital For Sick Children, Toronto, Ontario.
We evaluated the use of Bayesian forecasting for gentamicin therapy in
outborn infants weighing 1000 g or less irrespective of postnatal age.
Dosages were individualized using a computer program, guided by early serum
gentamicin assays after a loading dose and a database of population
kinetics. Steady-state gentamicin levels achieved were compared with those
from a regimen based on guidelines. A total of 26 gentamicin courses were
individualized in 19 infants of 22 to 33 weeks' gestation, weighing 500 to
1000 g at 1 to 41 days of age. All steady-state trough levels were between
1 and 2.4 mg/L; peak levels were between 4.4 and 9.3 mg/L. The 95%
confidence intervals were in almost identical ranges. The prevalence of
toxic and suboptimal trough levels was less when compared with that of 23
gentamicin courses based on guidelines in 17 control infants. We conclude
that early individualized gentamicin dosage over a range of postnatal age
is a practical alternative and serum level distributions appear superior.
