What is a suitable antibiotic for discharge in a patient treated with Zosyn (piperacillin/tazobactam) for urinary tract infection (UTI) and pneumonia (PNA)?

From the Guidelines

For a patient being discharged after treatment with Zosyn (piperacillin-tazobactam) for both urinary tract infection (UTI) and pneumonia (PNA), the most appropriate oral antibiotic option is levofloxacin 750mg daily for 5-7 days, as it provides excellent coverage of both respiratory and urinary pathogens with once-daily dosing, according to the American College of Physicians guidelines 1.

Key Considerations

• The choice of antibiotic should be guided by culture results if available, local resistance patterns, and patient-specific factors such as allergies or kidney function.
• Duration of therapy depends on clinical response, with pneumonia typically requiring 5-7 days and complicated UTIs 7-10 days of total therapy (including inpatient days).
• Ensure the selected antibiotic has activity against the identified or suspected pathogens from both infection sites.
• Consider infectious disease consultation for complex cases with resistant organisms.
• The transition from IV Zosyn to oral therapy is appropriate when the patient shows clinical improvement with resolution of fever, decreasing white blood cell count, and improving symptoms.

Alternative Options

• Amoxicillin-clavulanate 875/125mg twice daily for 7-10 days may also be considered, but levofloxacin is often preferred due to its broader coverage and once-daily dosing.
• Other options, such as nitrofurantoin or trimethoprim-sulfamethoxazole, may be considered for uncomplicated UTIs, but are not suitable for pneumonia treatment.

Evidence-Based Recommendations

• The American College of Physicians guidelines recommend short-course antibiotics for UTIs and pneumonia, with levofloxacin being a preferred option for its broad coverage and once-daily dosing 1.
• A recent multicenter noninferiority RCT found that short-course antibiotic therapy (5 days) was noninferior to longer courses (10 days) for patients with community-acquired pneumonia, supporting the use of shorter treatment durations 1.

From the FDA Drug Label

Levofloxacin tablets are indicated for the treatment of nosocomial pneumonia due to methicillin-susceptible Staphylococcus aureus, Pseudomonas aeruginosa, Serratia marcescens, Escherichia coli, Klebsiella pneumoniae, Haemophilus influenzae, or Streptococcus pneumoniae. Levofloxacin tablets are indicated for the treatment of complicated urinary tract infections due to Escherichia coli, Klebsiella pneumoniae, or Proteus mirabilis A good antibiotic to use when discharging a patient on Zosyn for UTI and PNA is levofloxacin.

• Key points:
  • Effective against a broad range of pathogens, including those commonly causing UTI and PNA
  • Indicated for the treatment of nosocomial pneumonia and complicated urinary tract infections 2

From the Research

Discharge Antibiotic Options for UTI and PNA

When discharging a patient who has been treated with Zosyn (piperacillin/tazobactam) for a urinary tract infection (UTI) and pneumonia (PNA), the choice of antibiotic depends on various factors including the causative organism, local susceptibility patterns, and the patient's clinical condition.

• First-line options: According to 3, for acute uncomplicated bacterial cystitis in otherwise healthy adult nonpregnant females, recommended first-line empiric antibiotic therapy includes a 5-day course of nitrofurantoin, a 3-g single dose of fosfomycin tromethamine, or a 5-day course of pivmecillinam.
• Second-line options: For more complicated cases or when first-line options are not suitable, second-line options include oral cephalosporins such as cephalexin or cefixime, fluoroquinolones, and β-lactams like amoxicillin-clavulanate 3.
• Considerations for ESBL-producing organisms: For UTIs due to ESBL-producing Enterobacteriaceae, oral options include nitrofurantoin, fosfomycin, pivmecillinam, amoxicillin-clavulanate, finafloxacin, and sitafloxacin 3.
• Parenteral treatment options for complicated UTIs: Parenteral options for UTIs due to ESBL-producing Enterobacteriaceae include piperacillin-tazobactam (for ESBL-E coli only), carbapenems, ceftazidime-avibactam, ceftolozane-tazobactam, and aminoglycosides like plazomicin 3.

Efficacy and Safety of Piperacillin/Tazobactam

• Clinical efficacy: A study published in 4 demonstrated the clinical and bacteriological efficacy and safety of piperacillin/tazobactam in treating hospitalized patients with complicated UTIs, showing favorable clinical response and bacteriological eradication rates.
• Heteroresistance and treatment failure: However, 5 highlights the potential for heteroresistance to piperacillin/tazobactam to lead to treatment failure, even when the isolate is deemed susceptible by standard antimicrobial susceptibility testing, emphasizing the need for careful consideration of antibiotic choices.

Choosing the Right Antibiotic

The choice of antibiotic upon discharge should be guided by the specific pathogens involved, their susceptibility patterns, and the patient's response to initial treatment with Zosyn. It is crucial to select an antibiotic that is effective against the causative organism and to use antibiotics wisely to minimize the development of resistance 3.