The 2011 Infectious Diseases Society of America guidelines for treatment of uncomplicated urinary tract infections (UTIs) recommend non-β-lactam antibiotics for empiric therapy. However, increasing Escherichia coli and Klebsiella spp. resistance to first-line antibiotic therapies has necessitated the need for alternative agents. Based on local antibiogram data, cephalexin has become the preferred oral antibiotic for empiric treatment of UTIs at our institution. The purpose of this single-center retrospective review was to assess clinical outcomes of patients discharged from the emergency department (ED) who received cephalexin for the treatment of uncomplicated UTIs. The primary outcome of this study was to assess the proportion of patients with clinical success 30 days after discharge from the ED. Patients were excluded if they were <18 years of age, received ≥10 days of cephalexin, received antibiotics for any indication other than uncomplicated UTI, received antibiotics within 60 days of their ED visit, or had structural abnormalities. A total of 264 patients were included for evaluation, and 214 patients (81.1%) met the criteria for clinical success. Overall, 28 (10.6%) patients required a change in antibiotics based on cultures and sensitivities, 18 (6.8%) patients returned for nonresolving or worsening symptoms, and 4 (1.5%) patients required both a change in antibiotics and returned for nonresolving or worsening symptoms. Short courses of twice-daily cephalexin appear to be a safe and effective option for the empiric treatment of uncomplicated UTIs.

BackgroundGram-negative (GN) infections in ICU patients have increased antibiotic resistance owing to higher minimum inhibitory concentrations (MICs). Piperacillin/tazobactam (PTZ) 3.375 g extended infusion (EI) may be used as an empiric agent. GN organisms with PTZ MICs > 16/4 may not be adequately covered by this regimen. The objective of this study was to evaluate MICs of GN isolates from the ICU to determine whether PTZ 3.375 g EI is an appropriate empiric regimen for ICU patients. Appropriateness of empiric antibiotic therapy was defined as PTZ MIC ≤16/4 in greater than 80% of isolates. The secondary objective was to evaluate patient specific risk factors that may be associated with elevated PTZ MICs in GN pathogens.MethodsAll ICU patients admitted from January to December 2017 with a confirmed GN pathogen from a non-urinary source were included. Patients were excluded if they had cystic fibrosis, cultures obtained >48 hours prior to ICU admission, or they were incarcerated. Patients’ electronic medical records were reviewed for the following data: age, sex, ethnicity, location prior to ICU admission, GN pathogen, culture source, risk factors for multi-drug-resistant organisms (dialysis, injection drug use, indwelling catheter, wounds/trauma), pathogen susceptibility profile, risk modifying co-morbidities (diabetes, heart failure, chronic kidney disease, and liver disease) and creatinine clearance.Results231 patients were included in the study. The average patient was 56.7 years old ±16.95. The majority of patients were white (64.1%) and male (69.7%). There were no significant differences in baseline characteristics between patients with PTZ MICs >16/4 and those with MICs ≤16/4. Pseudomonas aeruginosa (41%) was the primary organism identified and 28% of all GN isolates had MICs >16/4. Dialysis (P = 0.028), IV antibiotics (P < 0.001) and presence of wounds or trauma (P = 0.018) were all associated with elevated MICs.ConclusionCurrent PTZ EI 3.375g dosing may not provide adequate empiric coverage of GN pathogens for ICU patients especially for patients who received previous IV antibiotics, are on dialysis, or have the presence of wounds or trauma.Disclosures All authors: No reported disclosures.

Background: Piperacillin/tazobactam (PTZ) extended infusion (EI) is often used empirically in the intensive care unit (ICU). Gram-negative (GN) organisms with PTZ minimum inhibitory concentrations (MICs) >16/4 µg/mL are considered intermediate or resistant. Objective: The objective of this study was to evaluate MICs of GN isolates from the ICU to determine whether the hospital protocol for PTZ 3.375 g EI over 4 hours administered every 8 hours is an appropriate empiric regimen for ICU patients and to evaluate patient-specific risk factors associated with elevated MICs. Methods: All ICU patients admitted during 2017 with a confirmed GN organism from a non-urinary source were included for retrospective chart review. Patients with cystic fibrosis or cultures obtained >48 hours prior to ICU admission were excluded. Demographics, GN organism, culture source, risk factors for resistance, susceptibility profile, comorbidities, and creatinine clearance were collected. Appropriateness was defined as PTZ MIC ≤16/4 µg/mL in >80% of isolates. Results: Two hundred and thirty-one patients were included. The average patient was 56 years old. The majority of patients were white (64.1%) and male (69.7%). Pseudomonas aeruginosa (41%) was the most common organism isolated. Overall, 28% of GN isolates had MICs >16/4 µg/mL. Dialysis ( P = .01), intravenous antibiotics within 90 days ( P < .001), and presence of wounds/trauma ( P = .01) were associated with elevated MICs. Conclusion: Current PTZ EI 3.375 g dosing regimens may not provide adequate empiric coverage for some GN organisms in ICU patients, especially for those who have previously received intravenous antibiotics, are on dialysis, or have wounds/trauma.

Background Current IDSA guidelines for the treatment of UTIs discourage oral β-lactams based on lack of adequately powered studies to assess efficacy compared to fluoroquinolones or TMP-SMX. However, increasing E. coli and Klebsiella spp. resistance to first-line antibiotics has necessitated the need for alternative agents. Methods This was a single-center retrospective chart review of adult patients discharged from the University of New Mexico ED with twice-daily cephalexin for the treatment of uncomplicated UTIs from January 1, 2019 to December 31, 2019. Patients were excluded if &lt; 18 years of age, received ≥ 10 days of cephalexin, received antibiotics for other indications, received antibiotics within 60 days prior to ED visit, or had structural abnormalities. The primary outcome of this study was the proportion of patients with clinical success 30 days after discharge from the ED. Patients not meeting criteria for clinical failure were classified as clinical success. Clinical failure was defined as return of patient within 30 days due to non-resolving or worsening UTI symptoms or change in antibiotic therapy after discharge based on urine culture and susceptibilities. Results A total of 264 patients were included for evaluation. The average age was 56.0 ± 20.2 years and 82.6% were female. Patients received an average 5.6 ± 0.9 days of antibiotic therapy including IV therapy. Of the 264 patients included for evaluation, 81.1% met criteria for clinical success. Of the patients with clinical failure, 29 (13.6%) required a change in antibiotics based on cultures and sensitivities, 17 (6.4%) returned for non-resolving or worsening symptoms, and 4 (1.5%) required both a change in antibiotics and returned for non-resolving or worsening symptoms. Conclusion Short courses of twice-daily cephalexin appear to be safe and effective for empiric treatment of uncomplicated UTIs. Adding β -lactams back to the antibiotic armamentarium for UTI treatment may delay the development of resistance to non- β -lactam antibiotics, ensuring their future utility. Disclosures All Authors: No reported disclosures