What is the recommended treatment for acute uncomplicated cystitis?

Treatment of Acute Uncomplicated Cystitis

Nitrofurantoin monohydrate/macrocrystals (100 mg twice daily for 5 days) is the preferred first-line treatment for acute uncomplicated cystitis in women, offering clinical cure rates of 88-93% with minimal resistance patterns and limited collateral damage to normal flora. 1

First-Line Treatment Options

The choice of empirical therapy depends critically on local resistance patterns and patient-specific factors:

Nitrofurantoin (Preferred Agent)

• Nitrofurantoin monohydrate/macrocrystals 100 mg twice daily for 5-7 days is recommended as first-line therapy by IDSA guidelines 1
• Clinical cure rates range from 88-93% and bacterial cure rates from 81-92% 1
• Demonstrates equivalent efficacy to ciprofloxacin (93% vs 95%) and trimethoprim-sulfamethoxazole (93% vs 95%) 1
• Minimal resistance development and limited impact on gut and vaginal flora make this the optimal choice when no contraindications exist 1

Trimethoprim-Sulfamethoxazole (Conditional First-Line)

• TMP-SMX 160/800 mg twice daily for 3 days should only be used when local resistance rates are documented to be <20% or when susceptibility is confirmed 2, 1
• When used appropriately, achieves clinical cure rates of 90-100% and bacterial cure rates of 85-93% 2
• Critical caveat: Efficacy drops dramatically against resistant organisms (clinical cure 41-54% vs 84-88% for susceptible strains) 2, 1
• The 20% resistance threshold is based on expert consensus from clinical trials, in vitro studies, and mathematical modeling 1

Fosfomycin (Alternative First-Line)

• Fosfomycin trometamol 3 g single dose is FDA-approved for uncomplicated UTI in women 3
• Clinical cure rates approximately 90%, though microbiological eradication may be lower (78%) compared to nitrofurantoin (86%) 1, 3
• Particularly useful for patients with sulfa allergies or when adherence to multi-day regimens is a concern 1
• FDA labeling notes inferiority to ciprofloxacin and TMP-SMX but equivalence to nitrofurantoin 3

Second-Line Treatment Options

Fluoroquinolones (Reserve for Specific Situations)

• Ciprofloxacin, levofloxacin, ofloxacin, or norfloxacin for 3 days are highly effective but should be reserved as alternative agents 1
• These agents cause significant collateral damage to normal flora and promote resistance 1
• Should be preserved for more serious infections like pyelonephritis 1
• Use only when first-line agents cannot be used due to allergy, intolerance, or documented resistance 1

Beta-Lactam Agents (Use with Caution)

• Amoxicillin-clavulanate, cefdinir, cefaclor, or cefpodoxime-proxetil for 3-7 days are appropriate only when first-line agents are contraindicated 2, 1
• Generally demonstrate inferior efficacy and higher adverse effect rates compared to other UTI antimicrobials 2, 1
• Cephalexin is less well-studied but may be appropriate in certain settings 2, 1

Agents to Avoid

Never use amoxicillin or ampicillin for empirical treatment due to poor efficacy and extremely high worldwide resistance rates (often >30-40%) 2, 1

Treatment Algorithm

Step 1: Confirm diagnosis - Dysuria and frequency in an immunocompetent woman of childbearing age without comorbidities or urologic abnormalities 4

Step 2: Assess local resistance patterns

• If TMP-SMX resistance <20% in your community: Choose between nitrofurantoin (5 days) or TMP-SMX (3 days) 2, 1
• If TMP-SMX resistance ≥20% or unknown: Use nitrofurantoin (5 days) as first choice 1

Step 3: Consider patient-specific factors

• Sulfa allergy: Use nitrofurantoin or fosfomycin 1
• Penicillin allergy: Use nitrofurantoin, TMP-SMX (if resistance <20%), or fosfomycin 1
• Both sulfa and penicillin allergies: Use fosfomycin or consider fluoroquinolone if first-line options unavailable 1
• Adherence concerns: Consider fosfomycin single dose 1

Step 4: Prescribe appropriate duration

• Nitrofurantoin: 5-7 days 1
• TMP-SMX: 3 days 1
• Fosfomycin: Single dose 3
• Fluoroquinolones: 3 days 1
• Beta-lactams: 3-7 days 1

Common Pitfalls to Avoid

• Using fluoroquinolones as first-line therapy despite their high efficacy - this promotes resistance to agents needed for serious infections 1
• Prescribing treatment durations longer than recommended - studies show 73-82% of prescriptions exceed guideline-recommended durations, contributing to unnecessary antibiotic exposure 5
• Assuming TMP-SMX is always appropriate without knowing local resistance patterns - resistance rates vary dramatically by region 2, 1
• Treating male cystitis with short-course regimens - men require 7-day fluoroquinolone therapy, not the 3-5 day regimens used in women 6

Special Population: Male Cystitis

Male cystitis requires fundamentally different treatment and should never be treated with short-course regimens 6:

• First-line: Ciprofloxacin 500 mg twice daily for 7 days or levofloxacin 500-750 mg once daily for 7 days 6
• Alternative: TMP-SMX 160/800 mg twice daily for 7-14 days (only if local resistance <20%) 6
• Avoid: Nitrofurantoin 5-day courses, fosfomycin single dose, and other short-course regimens are inadequate 6