Should a patient with multiple myeloma on bortezomib (Velcade) be treated for a urinary tract infection with 50-100K Colony-Forming Units (CFU) of Staphylococcus species and sepsis?

Management of Septic Multiple Myeloma Patient with Staphylococcal UTI on Bortezomib

A septic multiple myeloma patient on bortezomib with 50-100K CFU Staphylococcus species in urine should receive immediate broad-spectrum antimicrobial therapy that includes coverage for Staphylococcus species, with prompt initiation within 1 hour of sepsis recognition. 1

Initial Assessment and Management

Sepsis Recognition and Initial Therapy

• Sepsis in an immunocompromised patient requires immediate intervention
• Administer broad-spectrum antibiotics within 1 hour of sepsis recognition 1
• Collect blood and urine cultures before antibiotic administration, but do not delay treatment

Antibiotic Selection for Septic Multiple Myeloma Patient with Staphylococcal UTI

• First-line regimen: Vancomycin (for MRSA coverage) PLUS a carbapenem (meropenem, imipenem/cilastatin, or doripenem) 1
  • Vancomycin dosing: 15-20 mg/kg loading dose, then 15-20 mg/kg every 8-12 hours (adjusted for renal function)
  • Carbapenem (e.g., meropenem 1g IV every 8 hours)
• This combination provides coverage for:
  • Staphylococcus species (including MRSA)
  • Gram-negative organisms including Pseudomonas
  • Anaerobes

Rationale for Broad-Spectrum Coverage

1. Multiple myeloma patients on bortezomib are immunocompromised
2. Staphylococcal UTIs are unusual and suggest potential:
   • Complicated UTI
   • Possible hematogenous spread
   • Higher risk of resistance
3. Sepsis presentation requires immediate effective coverage 1

Source Control

• Evaluate for urinary obstruction or anatomical abnormalities requiring intervention
• Consider urologic consultation for potential source control procedures 1
• If a urinary catheter is present, it should be removed and replaced after initiating antibiotics

Special Considerations for Multiple Myeloma Patients on Bortezomib

• Bortezomib increases infection risk through immunosuppression 2
• Multiple myeloma itself impairs immune function
• These patients have higher risk of unusual pathogens and drug-resistant organisms
• Consider temporarily holding bortezomib during acute infection (in consultation with oncology)

Antibiotic Adjustment and Duration

De-escalation Strategy

• Once culture and susceptibility results return, narrow therapy to the most appropriate agent 1
• For susceptible Staphylococcus species:
  • Consider de-escalation to a narrower agent based on susceptibilities
  • For MSSA: nafcillin, oxacillin, or cefazolin
  • For MRSA: continue vancomycin or consider daptomycin

Duration of Therapy

• For sepsis with bacteremia: 7-10 days of appropriate therapy 1
• For complicated UTI without bacteremia: 7 days of appropriate therapy
• Longer duration (10-14 days) may be appropriate given the patient's immunocompromised status 1

Monitoring Response

• Daily assessment for clinical improvement
• Monitor vital signs, inflammatory markers (CRP, procalcitonin)
• Repeat cultures if clinical improvement is not observed within 48-72 hours
• Consider infectious disease consultation if patient fails to improve

Common Pitfalls to Avoid

1. Delaying antibiotics: Never delay antimicrobial therapy in septic patients while awaiting cultures
2. Inadequate coverage: Staphylococcal UTI is unusual and may represent a complicated infection requiring broader coverage
3. Failure to consider source control: Evaluate for anatomical abnormalities or obstruction
4. Inadequate dosing: Ensure optimal antibiotic dosing based on pharmacokinetic/pharmacodynamic principles 1
5. Premature de-escalation: While de-escalation is important, ensure clinical improvement before narrowing therapy

By following this approach, you can optimize outcomes for this high-risk patient with sepsis and a urinary source of infection while on immunosuppressive therapy for multiple myeloma.