Antibiotic treatment of neonates--does route of administration matter?

The pharmacokinetics of gentamicin (19 babies), benzylpenicillin (7 babies), mecillinam (15 babies), cefuroxime (15 babies), ceftriaxone (37 babies), and latamoxef (27 babies) were compared following intravenous or intramuscular administration in the neonate. The effect of oral or intravenous administration of chloramphenicol was examined in 47 babies. The pharmacokinetics following either intravenous or intramuscular administration were essentially the same. Cmax was equivalent after both routes except for gentamicin (Cmax higher following intravenous administration) and latamoxef (Cmax lower following intravenous administration). Although Tmax ranged between 0.4 and 1.5 h therapeutically effective serum concentrations were attained within 15 min of intramuscular administration of all antibiotics. Clinical rather than pharmacokinetic considerations should therefore dictate which route should be used. Oral administration of chloramphenicol resulted in significantly lower steady-state serum concentrations and therefore this route should be avoided in the young premature neonate.