Treatment of Urinary Tract Infections
For acute uncomplicated UTI in women, use first-line therapy with nitrofurantoin, trimethoprim-sulfamethoxazole (TMP-SMX), or fosfomycin based on local resistance patterns, treating for 3-7 days maximum. 1
First-Line Antibiotic Selection
The choice among first-line agents should be guided by your local antibiogram and individual patient factors 1:
- Nitrofurantoin: 100 mg twice daily for 5-7 days 1, 2
- Trimethoprim-sulfamethoxazole: 160/800 mg twice daily for 3 days 1, 2
- Fosfomycin trometamol: 3 g single dose 1, 2
These three agents are equally effective for clinical cure but cause less collateral damage (antimicrobial resistance) compared to fluoroquinolones or β-lactams. 1 Nitrofurantoin is particularly valuable for re-treatment since resistance rates remain low and decay quickly when present 1.
Treatment Duration
Treat for as short a duration as reasonable, generally no longer than 7 days. 1 Three-day therapy achieves similar symptomatic cure rates as 5-10 day regimens while reducing adverse effects (RR 0.83,95% CI 0.74-0.93) 3. Single-dose antibiotics should be avoided as they increase bacteriological persistence compared to short courses 1.
When to Obtain Urine Culture
Obtain urine culture and sensitivity with each symptomatic acute cystitis episode before initiating treatment in patients with recurrent UTIs. 1 This establishes baseline antimicrobial sensitivities and allows tailoring of therapy 1. For first-time uncomplicated cystitis in otherwise healthy women, diagnosis can be made without culture 2.
Second-Line Options
Reserve fluoroquinolones for more invasive infections rather than uncomplicated cystitis 2. Only use ciprofloxacin if local resistance is <10% and the patient has not used fluoroquinolones in the last 6 months. 1 β-lactam agents (amoxicillin-clavulanate, cefpodoxime-proxetil) are less effective as empirical first-line therapy 2.
Special Populations
Men with UTI
Treat for 7-14 days based on limited observational data. 2 Consider prostatitis if symptoms persist, which may require 14 days of therapy 1.
Women with Diabetes
Treat similarly to women without diabetes if no voiding abnormalities are present. 2 Use the same first-line agents for 3-7 days 2.
Recurrent UTI (≥2 infections in 6 months or ≥3 in 1 year)
Always obtain pre-treatment culture before initiating antibiotics. 1 Patient-initiated self-start therapy can be offered to reliable patients who will obtain urine specimens before starting treatment 1.
Critical Pitfalls to Avoid
Do not treat asymptomatic bacteriuria except in pregnant women or patients undergoing invasive urinary procedures 1. Treatment of asymptomatic bacteriuria fosters antimicrobial resistance and increases recurrent UTI episodes 1.
Avoid classifying recurrent UTI as "complicated" unless structural/functional urinary tract abnormalities, immunosuppression, or pregnancy are present 1. This misclassification leads to unnecessary broad-spectrum antibiotics with prolonged treatment durations 1.
Do not use broad-spectrum antibiotics empirically for uncomplicated UTI as this drives resistance without improving outcomes 1. Reserve agents like ceftazidime-avibactam, meropenem-vaborbactam, and imipenem-cilastatin-relebactam for carbapenem-resistant organisms 1, 4.
Resistant Organisms
For culture-proven resistance to oral antibiotics, use culture-directed parenteral antibiotics for no longer than 7 days. 1
For complicated UTI with systemic symptoms, use combination therapy with amoxicillin plus aminoglycoside, second-generation cephalosporin plus aminoglycoside, or IV third-generation cephalosporin. 1
Alternative to Immediate Antibiotics
Immediate antimicrobial therapy is more effective than delayed treatment or ibuprofen alone for symptom resolution 2. However, in select low-risk patients, pain relief with observation may be considered as uncomplicated UTI progresses to pyelonephritis in only 1-2% of cases 5.