Fluoroquinolones (FQs) are often preferred as oral step-down therapy for bloodstream infections (BSIs) due to favorable pharmacokinetic parameters; however, they are also associated with serious adverse events. The objective of this study was to compare clinical outcomes for patients who received an oral FQ versus an oral beta-lactam (BL) as step-down therapy for uncomplicated streptococcal BSIs. This multicenter, retrospective cohort study analyzed adult patients who completed therapy with an oral FQ or BL with at least one blood culture positive for a Streptococcus species from 1 January 2014 to 30 June 2019. The primary outcome was clinical success, defined as the lack of all-cause mortality, recurrent BSI with the same organism, and infection-related readmission at 90 days. A multivariable logistic regression model for predictors of clinical failure was conducted. A total of 220 patients were included, with 87 (40%) receiving an FQ and 133 (60%) receiving a BL. Step-down therapy with an oral BL was noninferior to an oral FQ (93.2% versus 92.0%; mean difference, 1.2%; 90% confidence interval [CI], −5.2 to 7.8). No differences were seen in 90-day mortality, 90-day recurrent BSI, 90-day infection-related readmission, or 90-day incidence of Clostridioides difficile-associated diarrhea. Predictors of clinical failure included oral step-down transition before day 3 (odds ratio [OR] = 5.18; 95% CI, 1.21, 22.16) and low-dose oral step-down therapy (OR = 2.74; 95% CI, 0.95, 7.90). Our results suggest that oral step-down therapy for uncomplicated streptococcal BSI with a BL is noninferior to an FQ.

中文翻译：

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氟喹诺酮与β-内酰胺口服降压治疗可用于单纯性链球菌血流感染。

由于有利的药代动力学参数，氟喹诺酮类药物（FQs）通常被优选作为口服降压疗法用于血流感染（BSIs）。但是，它们也与严重的不良事件有关。这项研究的目的是比较接受口服FQ与口服β-内酰胺（BL）作为单纯性链球菌BSI降压治疗的患者的临床结局。这项多中心，回顾性队列研究分析了完成口服FQ或BL治疗且至少一种链球菌血培养呈阳性的成年患者从2014年1月1日至2019年6月30日的新物种。主要结果是临床成功，定义为缺乏全因死亡率，相同生物体复发性BSI和90天感染相关的再入院。进行了多变量logistic回归模型来预测临床失败。包括220名患者，其中87名（40％）接受FQ，133名（60％）接受BL。口服BL的降压治疗不逊于口服FQ（93.2％比92.0％；平均差异1.2％； 90％置信区间[CI]，-5.2至7.8）。在90天死亡率，90天复发性BSI，90天感染相关的再次入院或90天艰难梭菌发病率方面没有差异相关的腹泻。临床失败的预测指标包括第3天之前的口服降压过渡（优势比[OR] = 5.18； 95％CI，1.21、22.16）和小剂量口服降压疗法（OR = 2.74； 95％CI，0.95， 7.90）。我们的结果表明，对于单纯性链球菌BSI并发BL的口服降压治疗不逊于FQ。