What is the appropriate treatment for a 92-year-old male with a complicated Urinary Tract Infection (UTI), significant glucosuria, hematuria, proteinuria, and leukocyturia, and a history of Methicillin-resistant Staphylococcus aureus (MRSA)?

Treatment of Complicated UTI in a 92-year-old Male with MRSA History

For a 92-year-old male with a complicated UTI and history of MRSA, intravenous vancomycin (30-60 mg/kg/day divided in 2-4 doses) is the recommended first-line treatment, with dosage adjusted for renal function. 1

Initial Assessment and Classification

• This patient's UTI should be classified as complicated due to:

  • Advanced age (92 years old) 1, 2
  • Male gender (all UTIs in males are considered complicated) 1
  • Significant laboratory abnormalities (glucosuria, hematuria, proteinuria, leukocyturia) 1
  • History of MRSA (increased risk of resistant organisms) 1

• The negative nitrite with large leukocyte esterase suggests a possible non-E. coli pathogen, which is more common in complicated UTIs 1

Empiric Treatment Recommendations

First-line Treatment:

• Intravenous vancomycin 30-60 mg/kg/day divided in 2-4 doses 1
  • Consider a loading dose of 25-30 mg/kg in seriously ill patients 1
  • Dose must be adjusted based on renal function, which is likely impaired in a 92-year-old 1
  • Duration: 7-14 days for complicated UTI 1

Alternative Options:

• Teicoplanin 6-12 mg/kg/dose IV q12h for three doses, then once daily 1
• Linezolid 600 mg IV/PO q12h (advantage of equivalent oral bioavailability) 1
• Daptomycin 4-6 mg/kg/dose IV once daily (higher dose for bacteremia if present) 1

Culture and Susceptibility Testing

• Obtain urine and blood cultures before initiating antibiotics 1
• Adjust therapy based on culture results and susceptibility patterns 1, 3
• Consider broader coverage initially due to the higher risk of multidrug-resistant organisms in this patient 1, 3

Special Considerations for MRSA History

• MRSA remains uniformly susceptible to glycopeptides (vancomycin, teicoplanin) which are drugs of choice 3
• Avoid empiric fluoroquinolones due to high resistance rates in MRSA 1, 4
• Consider adding coverage for gram-negative organisms with cefepime or piperacillin/tazobactam until culture results are available 1, 5

Treatment Duration and Follow-up

• Treat for 7-14 days for complicated UTI 1
• Consider longer duration (14 days) due to advanced age and MRSA history 1, 2
• Follow-up urine culture after completion of therapy to ensure eradication 2

Monitoring During Treatment

• Monitor renal function closely, especially with vancomycin therapy 1
• Watch for signs of treatment failure (persistent fever, worsening symptoms) 1
• Evaluate for urologic abnormalities that may require intervention 1
• Consider removal of any indwelling catheters if present 2

Transition to Oral Therapy

• Once clinically improved, consider transition to oral therapy based on susceptibility results 6
• Potential oral options for MRSA (if susceptible):
  • Trimethoprim-sulfamethoxazole (160-320/800-1600 mg PO q12h) 1
  • Linezolid 600 mg PO q12h 1
  • Doxycycline 100 mg PO q12h (if susceptible) 1, 7

Pitfalls to Avoid

• Don't treat asymptomatic bacteriuria in the elderly, but this patient has significant pyuria and symptoms warranting treatment 2
• Don't rely solely on disc sensitivity testing for cephalothin against MRSA at 35°C, as it may be unreliable 8
• Don't use fluoroquinolones empirically when local resistance rates exceed 10% 4
• Don't use rifampin as monotherapy due to rapid emergence of resistance 3