What are the appropriate antibiotics (Abx) for treating urinary tract infections (UTI) in inpatients?

From the Guidelines

For inpatient treatment of urinary tract infections (UTIs), empiric antibiotic therapy with an intravenous third-generation cephalosporin, such as ceftriaxone, is recommended as the first-line treatment for complicated UTI with systemic symptoms. This recommendation is based on the European Association of Urology guidelines on urological infections, which were updated in 2024 1. The guidelines suggest using a combination of antibiotics, such as amoxicillin plus an aminoglycoside or a second-generation cephalosporin plus an aminoglycoside, for the treatment of complicated UTIs. However, for patients with systemic symptoms, an intravenous third-generation cephalosporin is recommended as empirical treatment.

Some key points to consider when treating inpatient UTIs include:

• Managing any urological abnormality and/or underlying complicating factors, as recommended by the guidelines 1
• Avoiding the use of ciprofloxacin and other fluoroquinolones for empirical treatment of complicated UTI in patients from urology departments or when patients have used fluoroquinolones in the last 6 months, due to the risk of resistance 1
• Considering the local resistance rate when selecting an antibiotic, and only using ciprofloxacin if the local resistance rate is <10% 1
• Ensuring adequate hydration and monitoring renal function, as well as addressing any urinary retention or anatomical abnormalities

It is also important to note that the treatment duration and choice of antibiotic may vary depending on the severity of the infection and the patient's individual risk factors. However, the use of an intravenous third-generation cephalosporin as empirical treatment for complicated UTI with systemic symptoms is a key recommendation based on the most recent and highest quality evidence 1.

From the FDA Drug Label

The microbiological success rates in the evaluable per protocol (EPP) analysis in patients treated for UTI were 87.0% (40/46) for ertapenem and 90.0% (18/20) for ceftriaxone. The clinical success rates in the EPP analysis in patients treated for UTI were not explicitly stated, but the microbiological success rates were 87.0% for ertapenem and 90.0% for ceftriaxone 2. Key points:

• Ertapenem had a microbiological success rate of 87.0% in treating UTI.
• Ceftriaxone had a microbiological success rate of 90.0% in treating UTI.
• The clinical success rates for UTI treatment were not explicitly stated.
• Ertapenem may be considered for the treatment of complicated urinary tract infections (UTI) in inpatient settings, but the choice of antibiotic should be based on individual patient needs and local resistance patterns.

From the Research

Antibiotic Treatment for UTI in Inpatients

• The recommended first-line empiric antibiotic therapy for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females is a 5-day course of nitrofurantoin, a 3-g single dose of fosfomycin tromethamine, or a 5-day course of pivmecillinam 3.
• High rates of resistance for trimethoprim-sulfamethoxazole and ciprofloxacin preclude their use as empiric treatment of UTIs in several communities, particularly if patients who were recently exposed to them or in patients who are at risk of infections with extended-spectrum β-lactamases (ESBLs)-producing Enterobacteriales 3.
• Second-line options include oral cephalosporins such as cephalexin or cefixime, fluoroquinolones and β-lactams, such as amoxicillin-clavulanate 3.
• Parenteral treatment options for UTIs due to ESBLs-producing Enterobacteriales include piperacillin-tazobactam, carbapenems, ceftazidime-avibactam, ceftolozane-tazobactam, aminoglycosides, and fosfomycin 3.

Selection of First-Line IV Antibiotics for Acute Pyelonephritis

• The selection of first-line IV antibiotics for acute pyelonephritis in patients requiring emergency hospital admission is crucial 4.
• Initial antibiotic treatment failure was significantly correlated to C-reactive protein in complicated AP and to positive blood culture in uncomplicated AP 4.
• A positive blood culture was the representative risk factor that related to both initial treatment failure and longer duration of the given antibiotics in uncomplicated AP 4.

Diagnosis, Treatment, and Prevention of Urinary Tract Infection

• The diagnosis of uncomplicated cystitis and pyelonephritis is usually easily made based on the clinical presentation, whereas the diagnosis in patients with complicated UTI is often more complex 5.
• Treatment of cystitis is usually straightforward with one of several effective short-course antimicrobial regimens, although antimicrobial resistance continues to increase and can complicate treatment choices in certain areas 5.

Ceftriaxone as a Treatment Option

• Ceftriaxone is a new 'third generation' semisynthetic cephalosporin with a long half-life which has resulted in a recommended once daily administration schedule 6.
• Ceftriaxone has been effective in treating infections due to other 'difficult' organisms such as multidrug-resistant Enterobacteriaceae, including complicated and uncomplicated urinary tract infections 6.

Urinary Tract Infections in Inpatients

• Urinary tract infection (UTI) is one of the major nosocomial infections, and in more than 80% of cases it is related to the use of urological devices, especially linked to the misuse of urinary catheters 7.
• Empirical treatment should be based on local epidemiology, severity criteria, and risk of multiresistant bacteria 7.