What medications can cause cystitis?

Medications That Can Cause Cystitis

Cyclophosphamide is the most well-documented medication that can cause hemorrhagic cystitis, which can affect the entire urinary tract including the bladder, ureters, and kidneys. 1

Medications Associated with Cystitis

Chemotherapeutic Agents

• Cyclophosphamide: Most commonly associated with hemorrhagic cystitis, which can be severe and potentially fatal. The toxic metabolite acrolein directly damages the urothelium, causing inflammation, ulceration, necrosis, fibrosis, and contracture 1
• Hemorrhagic cystitis can occur with both short-term and long-term use of cyclophosphamide, and can develop even after a single low dose (as little as 600 mg/m²) 2
• Prevention strategies include aggressive hydration, forced diuresis, frequent bladder emptying, and administration of mesna (a uroprotective agent that binds to acrolein) 1

Antibiotics

• Nitrofurantoin: While commonly used to treat cystitis, paradoxically it can cause chemical cystitis, especially with prolonged use or in patients with renal insufficiency (CrCl < 30 ml/min) 3, 4
• Sulfonamides (including trimethoprim-sulfamethoxazole): Can cause chemical irritation of the bladder mucosa with prolonged use 5
• Fluoroquinolones: May cause bladder irritation in some patients, particularly with prolonged use 5

Other Medications

• Nonsteroidal anti-inflammatory drugs (NSAIDs): Can cause chemical cystitis through inflammatory mechanisms 1
• Tiaprofenic acid: A specific NSAID that has been associated with cystitis
• Certain antidepressants: May contribute to cystitis-like symptoms through anticholinergic effects
• Ketamine: Recreational use has been associated with severe ulcerative cystitis

Risk Factors for Medication-Induced Cystitis

• Renal insufficiency: Decreased clearance of medications can lead to accumulation and increased risk of toxicity, particularly with nitrofurantoin 3
• Dehydration: Increases concentration of medication metabolites in urine 1
• Prior radiation therapy: Synergistic effect with medications like cyclophosphamide, increasing risk of hemorrhagic cystitis 1
• Urinary tract obstruction: Prolongs contact time between toxic metabolites and urothelium 1
• Female gender: Higher susceptibility to medication-induced cystitis 6, 7

Clinical Presentation and Management

Symptoms

• Dysuria, frequency, urgency, and suprapubic pain 6, 7
• Hematuria (especially with cyclophosphamide-induced hemorrhagic cystitis) 2
• Symptoms may persist despite antibiotic treatment 7

Management

• Discontinuation of the offending agent when possible 1
• Hydration: Increased fluid intake to dilute urine and reduce irritation 1
• Uroprotective agents: Mesna for cyclophosphamide-induced cystitis 1
• Pain management: For symptomatic relief 6
• Intravesical therapies: In severe cases, particularly for hemorrhagic cystitis 6

Prevention Strategies

• For cyclophosphamide:

  • Aggressive hydration before and during treatment 1
  • Administration of mesna 1
  • Frequent bladder emptying 1
  • Consider alternative immunosuppressive agents in high-risk patients 5

• For antibiotics:

  • Use appropriate dosing based on renal function 3
  • Limit duration of therapy to recommended guidelines (e.g., 3-5 days for uncomplicated cystitis) 5
  • Consider alternative agents in patients with risk factors 5

• General measures:

  • Maintain adequate hydration during medication use 1
  • Monitor for early symptoms of cystitis 2
  • Regular urinalysis in patients on high-risk medications 5

Special Considerations

• In patients with a history of interstitial cystitis or recurrent UTIs, careful selection of medications is essential to avoid exacerbation 6, 7
• Patients receiving cyclophosphamide should be monitored for signs of hemorrhagic cystitis, and prompt intervention may be life-saving 2
• Consider alternative immunosuppressive regimens (e.g., rituximab) in patients with high risk of cyclophosphamide-induced cystitis 5