Over the past 5 yr, we have conducted two clinical and two pharmacokinetic investigations of cefotaxime (CTX) and desacetylcefotaxime (dCTX) in neonates, infants, and children. A total of 50 children with culture-proven bacterial meningitis were randomized to receive either 200 mg/kg/day of CTX (n = 23, mean age 24.4 mo) or standard doses of ampicillin (AMP) and chloramphenicol succinate (CAPS; n = 27, mean age 16.6 mo). Results were similar between the CTX and Amp/CAPS groups for clinical/microbiological cures (100% versus 96%, respectively) and for survival without sequelae (78% vs. 77%, respectively). All bacterial isolates were sensitive to CTX, and the comparison of the MIC/MBC values for CTX to the CSF bactericidal titers suggested antimicrobial activity for dCTX. In a second clinical trial, 20 infants (1 wk-3 mo) were treated with 200 mg/kg/day of CTX for Gram-negative enteric bacillary meningitis. Cultures of CSF obtained 24 hr after the initiation of treatment were sterile in all subjects. Survival and complication rates of 95% and 21%, respectively, were observed. This compared favorably to previously published experiences with alternate treatment regimens for Gram-negative meningitis in the newborn. In both meningitis studies, the safety profile for CTX was excellent.(ABSTRACT TRUNCATED AT 250 WORDS)