From the Guidelines
For gram-negative bacilli UTI treatment, the most effective option is an intravenous third-generation cephalosporin as empirical treatment for complicated UTI with systemic symptoms, as recommended by the European Association of Urology guidelines 1.
Treatment Options
- For uncomplicated cases, fluoroquinolones such as ciprofloxacin 250-500mg twice daily for 3-7 days can be effective, but should be reserved for more serious infections due to resistance concerns 1.
- For more severe infections, parenteral options include ceftriaxone 1-2g daily, gentamicin 5mg/kg daily, or piperacillin-tazobactam 3.375g every 6 hours 1.
- The treatment choice should be guided by local resistance patterns, patient allergies, and infection severity 1.
Duration of Treatment
- For adult pyelonephritis, the recommended duration of treatment is 5 to 7 days for fluoroquinolones and 7 days for dose-optimized β-lactams 1.
- For adult febrile UTI, there is not enough evidence to provide a clear recommendation for duration of treatment, but it may be reasonable to treat in a similar fashion to pyelonephritis 1.
Important Considerations
- Gram-negative bacilli like E. coli, Klebsiella, and Proteus are the most common UTI pathogens, with increasing antibiotic resistance making empiric therapy challenging 1.
- Adequate hydration and completing the full antibiotic course are essential for successful treatment 1.
- For recurrent infections, consider longer treatment courses and investigation for anatomical abnormalities 1.
From the FDA Drug Label
AZACTAM is indicated for the treatment of the following infections caused by susceptible Gram-negative microorganisms: Urinary Tract Infections (complicated and uncomplicated), including pyelonephritis and cystitis (initial and recurrent) caused by Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Enterobacter cloacae, Klebsiella oxytoca*, Citrobacter species*, and Serratia marcescens* Levofloxacin tablets are indicated for the treatment of complicated urinary tract infections due to Escherichia coli, Klebsiella pneumoniae, or Proteus mirabilis Levofloxacin tablets are indicated for the treatment of uncomplicated urinary tract infections (mild to moderate) due to Escherichia coli, Klebsiella pneumoniae, or Staphylococcus saprophyticus
Treatment options for gram-negative bacilli UTI:
- Aztreonam (IV) is indicated for the treatment of urinary tract infections (complicated and uncomplicated) caused by susceptible Gram-negative microorganisms, including Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa, Enterobacter cloacae, Klebsiella oxytoca, Citrobacter species, and Serratia marcescens 2
- Levofloxacin (PO) is indicated for the treatment of complicated urinary tract infections due to Escherichia coli, Klebsiella pneumoniae, or Proteus mirabilis, and for the treatment of uncomplicated urinary tract infections (mild to moderate) due to Escherichia coli, Klebsiella pneumoniae, or Staphylococcus saprophyticus 3
From the Research
Treatment Options for Gram-Negative Bacilli UTI
- The recommended first-line empiric therapies for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females include a 5-day course of nitrofurantoin or a 3-g single dose of fosfomycin tromethamine 4.
- Second-line options include fluoroquinolones and β-lactams, such as amoxicillin-clavulanate 4.
- Current treatment options for UTIs due to AmpC- β -lactamase-producing organisms include fosfomycin, nitrofurantoin, fluoroquinolones, cefepime, piperacillin-tazobactam, and carbapenems 4, 5.
- Treatment options for UTIs due to ESBLs-producing Enterobacteriaceae include nitrofurantoin, fosfomycin, fluoroquinolones, cefoxitin, piperacillin-tazobactam, carbapenems, ceftazidime-avibactam, ceftolozane-tazobactam, and aminoglycosides 4, 5.
- Ceftazidime-avibactam, colistin, polymixin B, fosfomycin, aztreonam, aminoglycosides, and tigecycline are treatment options for UTIs caused by carbapenem-resistant Enterobacteriaceae (CRE) 4, 5.
- Treatment options for UTIs caused by multidrug-resistant (MDR)-Pseudomonas spp. include fluoroquinolones, ceftazidime, cefepime, piperacillin-tazobactam, carbapenems, aminoglycosides, colistin, ceftazidime-avibactam, and ceftolozane-tazobactam 4, 5.
Considerations for Treatment
- The use of fluoroquinolones for empiric treatment of UTIs should be restricted due to increased rates of resistance 4, 5.
- Aminoglycosides, colistin, and tigecycline are considered alternatives in the setting of MDR Gram-negative infections in patients with limited therapeutic options 4, 5.
- The choice of antibiotic should be based on individual patient risk profile, prior antibiotic treatment, spectrum of pathogens, antibiotic susceptibility, proven efficacy, ecological adverse effects, and side effects for the patient 6, 7, 8.