Gentamicin absorption during prophylactic use for necrotizing enterocolitis.

Gentamicin absorption was measured after oral administration in 18 neonates treated prophylactically in an attempt to decrease the incidence of necrotizing enterocolitis. Patients were given 10 mg/kg/day in four divided doses via nasogastric tube for a total of 10 days. Levels were assayed using the Emit system. Serum levels ranged between 0 and 2.2 micrograms/ml. Mean levels over 10 days were 0.42 +/- (SD) 0.47 micrograms/ml and did not vary significantly from day to day. From these data we conclude that enterally administered gentamicin is not absorbed to a degree that would result in toxic or even therapeutic serum concentrations.