What is the recommended antibiotic treatment for an otherwise healthy, non-pregnant woman with acute cystitis?

Recommended Antibiotic Treatment for Acute Uncomplicated Cystitis

Nitrofurantoin monohydrate/macrocrystals 100 mg twice daily for 5 days is the preferred first-line treatment for acute uncomplicated cystitis in otherwise healthy, non-pregnant women. 1

First-Line Treatment Options

Nitrofurantoin monohydrate/macrocrystals is the optimal choice because it demonstrates:

• Clinical cure rates of 88-93% and bacterial cure rates of 81-92% 1
• Minimal resistance patterns and limited collateral damage to normal flora 1
• Efficacy comparable to ciprofloxacin (93% vs 95%) and trimethoprim-sulfamethoxazole (93% vs 95%) 1
• Dose: 100 mg twice daily for 5 days 2, 1

Trimethoprim-sulfamethoxazole is an acceptable alternative ONLY if:

• Local resistance rates are confirmed to be <20% 2, 1
• The patient has not used it for UTI in the previous 3 months 2
• Dose: 160/800 mg (one double-strength tablet) twice daily for 3 days 2, 1
• Critical caveat: Efficacy drops dramatically against resistant organisms (41-54% cure rate vs 84-88% for susceptible strains) 1

Fosfomycin trometamol serves as another first-line option when others cannot be used:

• Single 3-gram dose 2, 1
• Clinical cure rates approximately 90%, though microbiological cure may be lower (78% vs 86% for nitrofurantoin) 1
• Should be avoided if early pyelonephritis is suspected 2

Alternative Agents (When First-Line Options Cannot Be Used)

Fluoroquinolones (ciprofloxacin, levofloxacin, ofloxacin, norfloxacin):

• Highly effective in 3-day regimens 2, 1
• Should be reserved as alternatives due to their propensity for collateral damage and promotion of resistance 2, 1
• Use only when first-line agents are contraindicated 2

β-Lactam agents (amoxicillin-clavulanate, cefdinir, cefaclor, cefpodoxime-proxetil):

• Require 3-7 day regimens 2, 1
• Generally have inferior efficacy and more adverse effects compared to first-line options 2, 1
• Use only when recommended agents cannot be used 2
• Cephalexin is less well-studied but may be appropriate in certain settings 2

Agents to Avoid

Never use amoxicillin or ampicillin empirically due to:

• Poor efficacy 2
• Very high prevalence of antimicrobial resistance worldwide 2, 1

Decision Algorithm

1. Start with nitrofurantoin 100 mg twice daily for 5 days unless contraindicated 1

2. If nitrofurantoin cannot be used, consider:

   • Trimethoprim-sulfamethoxazole IF local resistance <20% AND no recent use 2, 1
   • Fosfomycin 3 g single dose (accept slightly lower efficacy) 2, 1

3. If all first-line options are contraindicated, use fluoroquinolones for 3 days 2, 1

4. Reserve β-lactams as last resort when no other options available 2

Common Pitfalls to Avoid

• Do not use trimethoprim-sulfamethoxazole empirically without knowing local resistance patterns or if the patient used it recently 2, 1
• Avoid nitrofurantoin and fosfomycin if you suspect early pyelonephritis (fever, flank pain, systemic symptoms) as they have inadequate tissue penetration 2
• Do not prescribe fluoroquinolones as first-line despite their high efficacy—reserve them for more serious infections 2, 1
• Never use short-course regimens (3-5 days) in males—this requires 7-14 day treatment with different agents 3