Effect of frequency of administration on therapeutic efficacy of cefotaxime.

Clinical trials with cefotaxime have demonstrated that this antibiotic is effective and safe in a wide range of dosage schedules. Because of uncertainty about the most appropriate dosage regimen, physicians may be inclined to prescribe cefotaxime in higher doses and greater frequencies of administration than are required or economical (eg, dosing every six hours for an infection caused by a highly susceptible microorganism). To demonstrate that cefotaxime offers the physician great flexibility in dosing to achieve successful treatment with optimal cost-effectiveness, efficacy data from comparative and noncomparative studies in the United States were analyzed. Cases reviewed were those in which both the initial and final dosage regimens corresponded to one of several predetermined dosing schedules. These schedules included doses of 0.5 to 2.0 gm administered from two to six times a day. Patients were categorized according to severity of infection, and clinical and bacteriological responses were summarized according to frequency of administration. The analysis yielded 2,096 clinically evaluable cases and 1,755 bacteriologically evaluable cases. Uniformly good clinical and bacteriological success rates were achieved in all dosage regimens, indicating that in many circumstances the most appropriate regimen is every eight hours or, for highly susceptible pathogens, every 12 hours. Giving cefotaxime every six hours or more often is justified only when high concentrations of antibiotic are needed at the site of infection. Prescribing cefotaxime in the most appropriate dosage regimen will have a significant impact on the cost-effectiveness of antimicrobial therapy.