Use of antimicrobial drugs in general hospitals: patterns of prophylaxis

The patterns of prophylactic use of antimicrobial drugs were reviewed in 5288 charts drawn by a random method from 20 randomly selected short-stay general hospitals in Pennsylvania. About 10 per cent of hospitalized patients received antimicrobial drugs for prophylaxis in operations or nonsurgical procedures, and prophylaxis accounted for about 30 per cent of all antimicrobial drugs administered in hospitals. The drugs used most often for prophylaxis were cephalosporins, followed by benzyl penicillins, ampicillin and tetracyclines, in that order. Despite indications that prophylaxis, when useful at all, is effective only when given concurrently with and for 24 to 48 hours after operation, it was usually continued throughout hospitalization. Almost 80 per cent of prophylactic antimicrobial drugs were administered at least 48 hours after an operation or procedure -- suggesting that limiting prophylaxis to the first 24 to 48 hours, as currently recommended, would substantially reduce expenditures for antimicrobial drugs in hospitals.