What is the recommended dose and duration of Rocephin (Ceftriaxone) Intramuscular (IM) therapy for a Pseudomonas Putida Urinary Tract Infection (UTI)?

Ceftriaxone IM for Pseudomonas Putida UTI: Dosing and Duration

For Pseudomonas putida UTI, ceftriaxone IM is not the optimal first-line therapy; instead, use ceftazidime 2g IV q8h or amikacin 15 mg/kg IV once daily for 5-10 days, with treatment duration individualized based on clinical response. 1

Antibiotic Selection for Pseudomonas Putida UTI

• Ceftriaxone is not recommended as first-line therapy for Pseudomonas species UTIs due to limited activity against Pseudomonas species 1
• For Pseudomonas infections, including P. putida, preferred agents include:
  • Ceftazidime 2g IV q8h (preferred cephalosporin for Pseudomonas) 1
  • Amikacin 15 mg/kg IV once daily (particularly effective for UTIs) 1
  • Ciprofloxacin 400 mg IV q8h (if susceptible) 1

Treatment Duration for Pseudomonas UTIs

• For complicated UTIs caused by Pseudomonas species, including P. putida:
  • Recommended duration: 5-10 days 1
  • Duration should be based on clinical response, source control, and underlying comorbidities 1
  • Longer courses (10-14 days) may be needed for patients with delayed clinical response 1

If Ceftriaxone Must Be Used (Based on Susceptibility Testing)

• If susceptibility testing confirms P. putida sensitivity to ceftriaxone (uncommon):
  • Dose: 1-2g IM once daily 1, 2
  • Duration: 7-14 days 1
  • Consider adding amikacin 15 mg/kg once daily if there are risk factors for treatment failure 3

Special Considerations

• Pseudomonas putida often has different resistance patterns than P. aeruginosa but still frequently demonstrates resistance to ceftriaxone 1
• Always obtain urine culture and susceptibility testing to guide definitive therapy 1
• For multidrug-resistant P. putida, consider:
  • Ceftolozane/tazobactam 1.5-3g IV q8h 1
  • Ceftazidime/avibactam 2.5g IV q8h 1
  • Colistin (as a last resort) 1

Treatment Algorithm

1. Obtain urine culture and susceptibility testing before starting antibiotics 1
2. Start empiric therapy with ceftazidime 2g IV q8h or amikacin 15 mg/kg IV once daily 1
3. Adjust therapy based on susceptibility results 1
4. Evaluate clinical response after 48-72 hours 1
5. Complete 5-10 days of therapy for uncomplicated cases; consider 10-14 days for complicated cases 1
6. Switch to oral therapy (based on susceptibility) when clinically improved 1

Pitfalls to Avoid

• Avoid ceftriaxone monotherapy for known Pseudomonas infections unless susceptibility is confirmed 1, 4
• Do not use nitrofurantoin for Pseudomonas UTIs as it does not achieve adequate tissue concentrations 1
• Avoid short-course therapy (1-3 days) for Pseudomonas UTIs as this has been shown to be inferior 1
• Monitor renal function when using aminoglycosides like amikacin 1