What is the recommended treatment for cystitis?

Treatment of Uncomplicated Cystitis

Nitrofurantoin 100 mg twice daily for 5 days is the recommended first-line treatment for uncomplicated cystitis in women, offering highly effective therapy with minimal resistance and limited collateral damage to the microbiome. 1

First-Line Treatment Options for Women

The European Association of Urology identifies three equally appropriate first-line agents 1:

• Nitrofurantoin 100 mg twice daily for 5 days - preferred for its minimal resistance patterns and ecological safety 1, 2
• Fosfomycin trometamol 3 g as a single dose - convenient single-dose option, though may have slightly inferior efficacy compared to multi-day regimens 1, 3
• Pivmecillinam 400 mg three times daily for 3-5 days - effective where available 1, 4

Rationale for Nitrofurantoin as Top Choice

Nitrofurantoin demonstrates stable low resistance rates (approximately 5%) among E. coli in most regions and is classified in the WHO ACCESS group, indicating minimal collateral damage to the microbiome 2. This ecological safety profile makes it superior to alternatives that promote broader antimicrobial resistance 2.

Alternative Treatment Options

When first-line agents cannot be used, consider these alternatives based on local resistance patterns:

• Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 days - only appropriate when local E. coli resistance is documented to be <20% 1, 3, 5
• Cephalosporins (e.g., cefadroxil 500 mg twice daily for 3 days) - acceptable if local resistance is <20%, but generally less effective than first-line options 1, 3
• Fluoroquinolones - should be reserved for more serious infections due to their propensity for promoting resistance and unfavorable safety profile 1, 2

Important Caveat on Beta-Lactams

Beta-lactam agents (amoxicillin-clavulanate, cefpodoxime-proxetil) are not recommended as empirical first-line therapy due to inferior efficacy compared to other options 3, 5.

Treatment for Men

Men require longer treatment duration due to anatomical differences 1:

• 7-day treatment course is recommended for all men with cystitis 1
• Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 7 days or fluoroquinolones based on local susceptibility testing 1

Special Populations

Patients with Chronic Kidney Disease (CKD)

Critical renal function assessment determines antibiotic selection 6:

• If eGFR >30 mL/min: Nitrofurantoin 100 mg twice daily for 5 days remains appropriate 6
• If eGFR <30 mL/min: Fosfomycin trometamol 3 g single dose is preferred, as nitrofurantoin should be avoided due to reduced efficacy and increased toxicity risk 6
• Urine culture with susceptibility testing is strongly recommended before initiating therapy in CKD patients 6

Patients with Penicillin and Sulfa Allergies

For patients with documented allergies to both penicillin and sulfa antibiotics 6:

• Nitrofurantoin is the preferred option (if eGFR >30 mL/min) 6
• Fosfomycin trometamol is appropriate when nitrofurantoin is contraindicated 6
• Avoid cephalosporins without formal allergy testing due to cross-reactivity concerns (2-4% risk) 6

Pregnant Women

Urine culture is recommended for all pregnant women presenting with cystitis symptoms 1.

Diagnostic Approach

Diagnosis can be made based on clinical symptoms alone in most cases 1:

• Classic symptoms: dysuria, frequency, urgency, absence of vaginal discharge 1
• Urinalysis is recommended but urine culture is not routinely needed for uncomplicated cases 1, 5

When to Obtain Urine Culture

Urine culture with susceptibility testing is indicated for 1:

• Suspected acute pyelonephritis
• Symptoms that do not resolve or recur within 2-4 weeks after treatment
• Women with atypical symptoms
• Pregnant women
• All men with cystitis

Treatment Failure Management

If symptoms persist or recur within 2 weeks 1:

• Obtain urine culture and antimicrobial susceptibility testing 1
• Retreat with a 7-day regimen using a different agent 1

Common Pitfalls to Avoid

• Do not use nitrofurantoin when eGFR <30 mL/min - this leads to treatment failure and increased toxicity 6
• Do not prescribe trimethoprim-sulfamethoxazole empirically without knowing local resistance patterns; only use when resistance is documented <20% 1
• Do not reserve fluoroquinolones as first-line therapy - they should be preserved for more serious infections 1, 2
• Do not confuse acute bacterial cystitis with interstitial cystitis/bladder pain syndrome - the former requires antibiotics while the latter does not 4
• Do not fail to obtain cultures in CKD patients - this population requires guided therapy 6