Therapeutic interchange of cefazolin with metronidazole for cefoxitin.

The effects on patient outcome and drug therapy costs of a therapeutic interchange program using a cefazolin and metronidazole combination in place of cefoxitin were studied. A therapeutic interchange program was initiated in which the pharmacy department automatically replaced orders for cefoxitin with orders for a cefazolin and metronidazole combination. Data were compared for 100 consecutive patients who received cefoxitin before initiation of the program and the first 100 patients who received cefazolin and metronidazole as part of the program. The impact of the program on therapeutic efficacy, adverse effects associated with therapy, and drug therapy costs was assessed. The two patient groups were similar in age, gender, and white blood cell count. The failure rates for treatment or prophylaxis of infection did not significantly differ between the groups. Duration of therapy and incidence of adverse effects did not significantly differ between the groups. The average cost saving was +72 per patient for treatment with cefazolin and metronidazole instead of cefoxitin. A program for therapeutic interchange of cefazolin and metronidazole in place of cefoxitin demonstrated equivalent efficacy and adverse effects, as well as considerable cost savings.