Role of Antibiotics in Hemorrhagic Cystitis
Antibiotics should only be used in hemorrhagic cystitis when there is documented bacterial infection, as hemorrhagic cystitis is predominantly caused by chemical agents (cyclophosphamide, ifosfamide), radiation therapy, or viral infections—not bacterial pathogens. 1, 2
Understanding the Etiology
Hemorrhagic cystitis differs fundamentally from infectious cystitis:
- Primary causes are non-bacterial: Chemical compounds (oxaphosphorines), radiation therapy, viral infections, and idiopathic causes account for the vast majority of cases 1, 2
- Pathophysiology involves urothelial cell death and smooth muscle pyroptosis, not bacterial invasion 3
- The condition can be caused by infectious agents (bacterial, fungal, parasitic, or viral), but this represents a minority of cases 1
When to Use Antibiotics
Obtain urine culture before initiating antibiotics to document bacterial infection rather than treating empirically 4
Indications for antibiotic therapy:
- Documented bacterial UTI with positive urine culture showing significant bacteriuria 4
- Systemic signs of infection (fever, rigors, altered mental status) with positive cultures 4
- Catheter-associated UTI in patients with indwelling catheters who develop hemorrhagic cystitis 4
When NOT to use antibiotics:
- Asymptomatic bacteriuria should not be treated, even if cultures are positive without symptoms 4
- Chemical-induced hemorrhagic cystitis (cyclophosphamide, ifosfamide) requires supportive care, not antibiotics 1, 5
- Radiation-induced hemorrhagic cystitis is managed with bladder irrigation, fulguration, hyperbaric oxygen, or intravesical therapies—not antibiotics 2, 6
Antibiotic Selection If Infection Documented
If bacterial infection is confirmed, use first-line agents based on local resistance patterns:
- Nitrofurantoin monohydrate/macrocrystals 100 mg twice daily for 5-7 days 4, 7
- Fosfomycin trometamol 3 g single dose 4, 7
- Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3-7 days if local E. coli resistance <20% 4, 7
For complicated UTI with hemorrhagic cystitis:
- Amoxicillin plus aminoglycoside or third-generation cephalosporin for 7-14 days 4
- Duration should be 7 days minimum, extending to 14 days in men when prostatitis cannot be excluded 4
Critical Management Pitfalls
- Do not perform surveillance urine cultures in asymptomatic patients—bacteriuria without symptoms does not require treatment 4
- Do not use antibiotics empirically without documented infection, as this promotes resistance without addressing the underlying cause 1, 2
- Avoid fluoroquinolones as first-line therapy to preserve their efficacy for serious infections 7
- Never use amoxicillin or ampicillin empirically due to high resistance rates 7
Primary Treatment Focus
The mainstay of hemorrhagic cystitis management is addressing the underlying cause and controlling bleeding, not antibiotic therapy 2, 6: