Drug of Choice for Uncomplicated UTI
Nitrofurantoin 100 mg twice daily for 5 days is the drug of choice for uncomplicated urinary tract infections in women. 1, 2
First-Line Treatment Options
The most recent guidelines from IDSA and AUA establish a clear hierarchy for empiric treatment:
Nitrofurantoin monohydrate/macrocrystals 100 mg twice daily for 5 days is the preferred first-line agent due to minimal resistance patterns, limited collateral damage to gut flora, and clinical cure rates of 88-93% 1, 2
Fosfomycin trometamol 3 g single dose is an appropriate alternative first-line option, though it demonstrates slightly inferior efficacy compared to nitrofurantoin 1, 3
Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 days should only be used if local E. coli resistance rates are documented below 20% or if the infecting strain is confirmed susceptible 1, 4
Why Nitrofurantoin is Preferred Over Traditional Agents
The landscape has shifted dramatically from older recommendations:
TMP-SMX is no longer first-line due to rising resistance rates among uropathogens, with studies showing nitrofurantoin has lower treatment failure rates 1
Fluoroquinolones (ciprofloxacin, levofloxacin) should be reserved for more serious infections due to their propensity for collateral damage, increasing resistance, and FDA warnings about serious safety issues affecting tendons, muscles, joints, nerves, and the central nervous system 5, 1
β-lactam agents (amoxicillin-clavulanate, cefdinir, cefaclor, cefpodoxime-proxetil) have inferior efficacy and more adverse effects compared to nitrofurantoin, and should only be used when first-line agents cannot be tolerated 5
Amoxicillin or ampicillin alone should never be used empirically due to poor efficacy and very high worldwide resistance rates 5
Critical Contraindications and Caveats
Do not use nitrofurantoin if:
- Early pyelonephritis is suspected (inadequate tissue concentrations) 1, 2
- Patient is an infant under 4 months of age (risk of hemolytic anemia) 1
- Upper UTI or kidney cyst infection is present 1
Special Populations
For men with uncomplicated UTI:
- Always obtain urine culture and susceptibility testing before treatment 6
- Use trimethoprim, trimethoprim-sulfamethoxazole, or nitrofurantoin for 7 days (not 5 days as in women) 6
- Consider urethritis and prostatitis in the differential diagnosis 6
For patients ≥65 years old:
- Obtain urine culture with susceptibility testing to adjust therapy after initial empiric treatment 6
- Use same first-line antibiotics and durations as younger adults if nonfrail with no relevant comorbidities 6
For recurrent UTIs:
- Obtain urinalysis, urine culture, and sensitivity with each symptomatic episode prior to treatment 1
- Do not treat asymptomatic bacteriuria 1
- Omit surveillance urine testing in asymptomatic patients 1
When Culture is NOT Needed
- Uncomplicated cystitis in women with typical symptoms (frequency, urgency, dysuria, nocturia, suprapubic pain) without vaginal discharge can be diagnosed and treated empirically without office visit or urine culture 6, 7