Gupta Kalpana
Dis Mon. 2003 Feb;49(2):99-110. doi: 10.1067/mda.2003.10.
Management of uncomplicated urinary tract infections (UTIs) has traditionally been based on 2 important principles: the spectrum of organisms causing acute UTI is highly predictable (Escherichia coli accounts for 75% to 90% and Staphylococcus saprophyticus accounts for 5% to 15% of isolates), and the susceptibility patterns of these organisms have also been relatively predictable. As a result, empiric therapy with short-course trimethoprim-sulfamethoxazole (TMP-SMX) has been a standard management approach for uncomplicated cystitis.However, antibiotic resistance is now becoming a major factor not only in nosocomial complicated UTIs, but also in uncomplicated community-acquired UTIs. Resistance to TMP-SMX now approaches 18% to 22% in some regions of the United States, and nearly 1 in 3 bacterial strains causing cystitis or pyelonephritis demonstrate resistance to amoxicillin. Fortunately, resistance to other agents, such as nitrofurantoin and the fluoroquinolones, has remained low, at approximately 2%. Preliminary data suggest that the increase in TMP-SMX resistance is associated with poorer bacteriologic and clinical outcomes when TMP-SMX is used for therapy. As a result, these trends have necessitated a change in the management approach to community-acquired UTI. The use of TMP-SMX as a first-line agent for empiric therapy of uncomplicated cystitis is only appropriate in areas where TMP-SMX resistance prevalence is <10% to 20%. In areas where resistance to TMP-SMX exceeds this rate, alternative agents need to be considered.
传统上，单纯性尿路感染（UTIs）的管理基于两个重要原则：引起急性UTI的生物体谱具有高度可预测性（大肠杆菌占分离株的75%至90%，腐生葡萄球菌占5%至15%），并且这些生物体的药敏模式也相对可预测。因此，短疗程甲氧苄啶-磺胺甲恶唑（TMP-SMX）经验性治疗一直是单纯性膀胱炎的标准管理方法。然而，抗生素耐药性现在不仅成为医院获得性复杂性UTIs的主要因素，也成为社区获得性单纯性UTIs的主要因素。在美国的一些地区，对TMP-SMX的耐药率现在接近18%至22%，并且近三分之一引起膀胱炎或肾盂肾炎的细菌菌株对阿莫西林耐药。幸运的是，对其他药物如呋喃妥因和氟喹诺酮类的耐药性仍然很低，约为2%。初步数据表明，当TMP-SMX用于治疗时，TMP-SMX耐药性的增加与较差的细菌学和临床结果相关。因此，这些趋势使得社区获得性UTI的管理方法发生了改变。仅在TMP-SMX耐药率<10%至20%的地区，将TMP-SMX用作单纯性膀胱炎经验性治疗的一线药物才是合适的。在对TMP-SMX耐药率超过该比率的地区，需要考虑使用替代药物。
