Comparative efficacy of chloramphenicol, ampicillin, and co-trimoxazole in the treatment of typhoid fever.

Two clinical trials were conducted to compare the efficacy of 3 antimicrobial agents often recommended for the treatment of typhoid fever. Chloramphenicol was more effective than parenteral ampicillin or oral co-trimoxazole (trimethaprim/sulphamethoxazole) in reducing the duration of fever. Oral chloramphenicol was more effective than parenteral chloramphenicol probably because oral doses resulted in higher blood concentrations of the drug. However, parenteral chloramphenicol was given during the initial period of acute illness, without loss of efficacy.