Background
: The overuse and misuse of antimicrobial agents and their resultant emergence of resistant microorganisms have made choices regarding antimicrobial therapy more difficult. Therefore, a new system that separated prescribing and dispensing medicine began on July 1, 1997 to prevent overuse and misuse of medicine. We studied to evaluate changes of antibiotic sensitivities to causative microorganisms of urinary tract infection 2 years before and after the new medical system.

Methods : During each 2 years before and after the new medical system, we analyzed antibiotic sensitivities of causative microorganisms for urinary tract infection among the 447 outpatients who visited a hospital in GangNeung. The diagnosis of urinary tract infection was based on greater than 10⁵ CFU (Colony For Unit) per ml urine.

Results : The most common pathogenic microorganisms as E.coli (76.5%), followed by Klebsiella pneumoniae (5.1%), and Proteus mirabilis (3.6%) in urine culture. A first generation cephalosporin, cephalothin, against E.coli, had more significant sensitivity after the introduction of the new medical system (52.6%) than before (33.9%), especially in the 8th decade (P=0.023) and in females (P＜0.001). Also, trimethoprim/sulfamethoxazole against E.coli showed signifcant improving sensitivity (P=0.025).

Conclusion : There was little change of antibiotic sensitivity of urinary tract infection in outpatients before and after the new medical system in cephalothin and trimethoprim/sulfamethoxazole against E.coli. The change of antibiotic sensitivities will require further observation for a longer term after the introduction of the new medical system.