Antagonistic effect of chloramphenicol in combination with cefotaxime or ceftriaxone.

AUTOR(ES)

Asmar, B I

RESUMO

We evaluated the in vitro interaction at clinically attainable concentrations of cefotaxime and ceftriaxone with chloramphenicol against 26 clinical isolates of gram-negative rods, group B streptococci, and Staphylococcus aureus. Cefotaxime and ceftriaxone were bactericidal against all 26 organisms (MBC, 0.03 to 4 micrograms/ml). Chloramphenicol was bacteriostatic against 24 organisms (MBC, greater than or equal to 32 micrograms/ml) and bactericidal against two Escherichia coli isolates (MBC, 8 micrograms/ml). Checkerboard testing showed chloramphenicol to be antagonistic to the bactericidal activity of cefotaxime and ceftriaxone for all 24 bacteria for which chloramphenicol was bacteriostatic. Time kill curves for selected strains of E. coli and group B streptococci for which chloramphenicol was bacteriostatic showed antagonism of chloramphenicol to both cephalosporins. The combination of chloramphenicol with either cephalosporin was antagonistic in cases in which chloramphenicol was bacteriostatic against the above organisms and should be avoided in the treatment of infections caused by such organisms if bactericidal therapy is desired.

Documentos Relacionados

• A pneumococcal clinical isolate with high-level resistance to cefotaxime and ceftriaxone.
• Treatment of gonorrhoea with ceftriaxone.
• In vivo activity and pharmacodynamics of cefotaxime or ceftriaxone in combination with fosfomycin in fibrin clots infected with highly penicillin-resistant Streptococcus pneumoniae.
• Effect of cefotaxime or ceftriaxone treatment on nasopharyngeal Haemophilus influenzae type b colonization in children.
• Successful treatment of epiglottitis with two doses of ceftriaxone.