What is the recommended treatment for a urinary tract infection (UTI)?

Treatment of Urinary Tract Infections

For acute uncomplicated UTIs in women, use first-line antibiotics: nitrofurantoin for 5 days, trimethoprim-sulfamethoxazole for 3 days, fosfomycin as a single dose, or trimethoprim for 3 days, with treatment duration generally no longer than 7 days. 1

Acute Uncomplicated UTI - Initial Management

Diagnosis and Culture Requirements

• Obtain urine culture and sensitivity testing before initiating antibiotics in patients with recurrent UTIs (≥2 infections in 6 months or ≥3 in one year) 1
• For women with typical symptoms (frequency, urgency, dysuria, suprapubic pain) and no vaginal discharge, clinical diagnosis alone is sufficient for first episodes 2
• Patient-initiated self-start treatment is acceptable in select reliable patients while awaiting culture results 1

First-Line Antibiotic Selection

The following agents minimize collateral damage and antimicrobial resistance 1:

• Nitrofurantoin 100 mg twice daily for 5 days 1, 2
• Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 days (only if local resistance <20%) 1
• Fosfomycin 3g single dose 1
• Trimethoprim 100 mg twice daily for 3 days 2

Treatment Duration Principles

• Treat acute cystitis episodes with the shortest reasonable duration, generally no longer than 7 days 1
• Three-day therapy achieves similar symptomatic cure rates as 5-10 day therapy but with fewer adverse effects 3
• Single-dose antibiotics show higher bacteriological persistence rates and should be avoided except for fosfomycin 1

Recurrent UTI Management

Acute Episode Treatment

• Always obtain pre-treatment urine culture before initiating antibiotics 1
• Use prior culture data when available to guide empiric therapy while awaiting current results 1
• Nitrofurantoin is preferred for re-treatment since resistance rates remain low and decay quickly 1
• Avoid classifying recurrent UTI patients as "complicated" unless structural/functional abnormalities or immunosuppression exist, as this leads to unnecessary broad-spectrum antibiotic use 1

Prevention Strategies by Population

Postmenopausal women: 1

• Initiate vaginal estrogen with or without lactobacillus-containing probiotics as first-line prevention

Premenopausal women with post-coital infections: 1

• Low-dose antibiotic within 2 hours of sexual activity for 6-12 months
• Preferred agents: nitrofurantoin 50 mg, trimethoprim-sulfamethoxazole 40/200 mg, or trimethoprim 100 mg

Premenopausal women with non-coital infections: 1

• Daily antibiotic prophylaxis (most effective strategy, reducing UTI rate to 0.4/year)
• Alternative: methenamine hippurate and/or lactobacillus-containing probiotics for patients desiring non-antibiotic options

Critical Avoidance

• Do NOT treat asymptomatic bacteriuria in recurrent UTI patients (except pregnant women or those undergoing invasive urinary procedures) 1
• Treating asymptomatic bacteriuria fosters antimicrobial resistance and increases recurrence episodes 1
• Do NOT perform surveillance urine testing in asymptomatic patients 1

Complicated UTI Management

Definition and Risk Factors

Complicated UTIs occur with: 1

• Urinary tract obstruction at any site
• Foreign bodies (catheters, stents)
• Structural/functional abnormalities
• Male gender
• Pregnancy
• Diabetes mellitus
• Immunosuppression
• Healthcare-associated infections
• Multidrug-resistant organisms

Empiric Antibiotic Selection

For complicated UTI with systemic symptoms: 1

• Amoxicillin plus aminoglycoside, OR
• Second-generation cephalosporin plus aminoglycoside, OR
• Intravenous third-generation cephalosporin

Fluoroquinolone considerations: 1

• Only use ciprofloxacin if local resistance <10%
• Do NOT use fluoroquinolones empirically in urology department patients or those with fluoroquinolone use in last 6 months

Treatment Duration

• 7-14 days is generally recommended (14 days for men when prostatitis cannot be excluded) 1
• Shorter 7-day courses acceptable when patient is hemodynamically stable and afebrile for ≥48 hours 1
• Treatment duration should correlate with management of underlying abnormality 1

Multidrug-Resistant Organisms

Carbapenem-Resistant Enterobacteriaceae (CRE)

For complicated UTI due to CRE: 1

• Ceftazidime-avibactam 2.5g IV every 8 hours
• Meropenem-vaborbactam 4g IV every 8 hours
• Imipenem-cilastatin-relebactam 1.25g IV every 6 hours
• Plazomicin 15 mg/kg IV every 12 hours

For simple cystitis due to CRE: 1

• Single-dose aminoglycoside is acceptable

Men with UTI

• Always prescribe antibiotics for men with lower UTI symptoms 2
• Always obtain urine culture and susceptibility testing 2
• Consider urethritis and prostatitis as alternative diagnoses 2
• First-line agents: trimethoprim, trimethoprim-sulfamethoxazole, or nitrofurantoin for 7 days 2

Older Adults (≥65 years)

• Obtain urine culture with susceptibility testing to adjust empiric therapy 2
• First-line antibiotics and treatment durations identical to younger adults in nonfrail patients without relevant comorbidities 2

Common Pitfalls

• Avoid treating asymptomatic bacteriuria, which increases resistance and recurrence 1
• Do not use broad-spectrum antibiotics for uncomplicated infections 1
• Consider local antibiogram patterns when selecting empiric therapy 1
• If persistent symptoms despite treatment, repeat urine culture before prescribing additional antibiotics 1
• Resistance rates for trimethoprim (21.4%) and cotrimoxazole (19.3%) exceed 15% in recurrent UTIs, limiting their use 4