What are the symptoms and treatment options for urinary tract infections (UTIs)?

Symptoms and Treatment of Urinary Tract Infections

Symptoms of UTI

The hallmark symptoms of UTI include dysuria (painful urination), urinary frequency, urgency, and suprapubic discomfort, with hematuria occurring in some cases. 1

• Lower UTI (cystitis) presents with dysuria, frequency, urgency, and sometimes hematuria 1
• Upper UTI (pyelonephritis) adds fever, flank pain, and systemic symptoms to the lower tract symptoms 1
• Nocturia and incontinence may also occur 1
• In febrile infants (2-24 months), fever may be the only presenting sign 1

A critical pitfall: symptoms alone are insufficient for diagnosis—microbiological confirmation with urine culture is essential before initiating treatment, especially in recurrent cases. 1

Diagnostic Approach

Obtain urinalysis and urine culture before starting antibiotics to guide therapy and document true infection. 1

• For reliable culture, use catheterized specimen or suprapubic aspiration in infants 1
• Clean-catch midstream urine is acceptable in adults who can provide adequate specimen 1
• Positive culture requires ≥50,000 CFU/mL of uropathogen with pyuria or bacteriuria on urinalysis 1
• If initial specimen suggests contamination, obtain repeat culture, preferably catheterized 1

Treatment of Uncomplicated UTI in Women

First-line therapy for acute uncomplicated cystitis is nitrofurantoin (5 days), trimethoprim-sulfamethoxazole (3 days if local resistance <20%), or fosfomycin (single 3g dose), selected based on local antibiogram. 1, 2, 3

First-Line Agents

• Nitrofurantoin: 5-day course, minimal resistance development, low collateral damage 1, 2
• Trimethoprim-sulfamethoxazole (TMP-SMX): 3-day course, but only if local resistance <20% 1, 4
• Fosfomycin tromethamine: Single 3g dose, convenient but slightly lower efficacy 1, 2, 3

Treatment Duration

Treat uncomplicated UTI for as short a duration as reasonable, generally no longer than 7 days, with 3-5 days preferred for most first-line agents. 1, 3

• Single-dose therapy shows higher failure rates and should be avoided 1
• Longer courses (>7 days) increase resistance without improving outcomes 1

Second-Line Agents (Use Only When First-Line Inappropriate)

• Oral cephalosporins (cephalexin, cefixime) 1, 2
• Beta-lactams like amoxicillin-clavulanate 1, 5
• Fluoroquinolones should NOT be used for uncomplicated UTI due to serious adverse effects and unfavorable risk-benefit ratio 1, 6

Critical warning: The FDA issued an advisory in 2016 against fluoroquinolones for uncomplicated UTI due to disabling and serious adverse effects. 1

Treatment of Complicated UTI

For complicated UTI (including those with hematuria, catheter-associated, or structural abnormalities), use empiric combination therapy with broader spectrum agents for 7-14 days. 7

Empiric Combination Therapy Options

• Amoxicillin plus aminoglycoside 7
• Third-generation cephalosporin 7
• Treatment duration: 7-14 days 7

Management Principles

• Remove or replace urinary catheter as soon as clinically appropriate 7
• Obtain urine culture before initiating antibiotics 7
• Manage underlying abnormalities (obstruction, foreign body) concurrently 7
• Adjust therapy based on culture results from empiric to targeted treatment 7

Treatment of Recurrent UTI

For recurrent UTI (≥2 infections in 6 months or ≥3 in 1 year), obtain culture with each symptomatic episode before treatment and consider prophylactic strategies after acute treatment. 1

Acute Episode Management

• Use same first-line agents as uncomplicated UTI 1
• Patient-initiated self-start treatment acceptable in reliable patients who obtain pre-treatment cultures 1
• Avoid classifying as "complicated" unless true structural/functional abnormalities exist 1

Prophylaxis Options (After Discussion of Risks/Benefits)

Postmenopausal women: Vaginal estrogen with or without lactobacillus-containing probiotics 1

Premenopausal women with post-coital infections: Low-dose antibiotic within 2 hours of sexual activity 1

Premenopausal women with non-coital infections: Daily low-dose antibiotic prophylaxis (nitrofurantoin, TMP-SMX, or cephalexin) for 6-12 months 1

Non-antibiotic alternatives: Methenamine hippurate and/or lactobacillus-containing probiotics 1

Critical Prophylaxis Considerations

• Prophylaxis reduces UTI frequency only during active use; recurrence returns to baseline after cessation 1
• Nitrofurantoin pulmonary/hepatic toxicity risk is extremely low (0.001% and 0.0003% respectively) 1
• Antibiotic choice should consider prior organism susceptibility, allergies, and stewardship principles 1

Antibiotic Resistance Considerations

Nitrofurantoin maintains the lowest resistance rates among first-line agents, with resistance decaying quickly even when present (20% at 3 months, 5.7% at 9 months). 1

• Fluoroquinolones and cephalosporins cause significant collateral damage to normal flora and promote resistance 1
• TMP-SMX resistance often persists (78.3% at follow-up) 1
• Local antibiogram should guide empiric choices 1

Special Populations

Pediatric Patients (2-24 months with febrile UTI)

• Oral options: cephalosporin, amoxicillin-clavulanate, or TMP-SMX based on local susceptibility 1
• Avoid nitrofurantoin in febrile infants—inadequate parenchymal concentrations 7
• Treatment duration: 7-14 days total 1, 7
• Obtain renal ultrasound after confirmed UTI 1

Multidrug-Resistant Organisms

• For ESBL-producing organisms: ceftazidime-avibactam, meropenem-vaborbactam, or imipenem-cilastatin-relebactam 7, 2
• High-dose amoxicillin-clavulanate may overcome ESBL resistance in select outpatient cases 7

Critical Pitfalls to Avoid

Do NOT treat asymptomatic bacteriuria in non-pregnant women, even with recurrent UTI history—this increases resistance and recurrence rates. 1

• Asymptomatic bacteriuria should not be treated even when hematuria is present 7
• Avoid surveillance urine testing in asymptomatic patients with recurrent UTI 1
• Do not use fluoroquinolones as first-line therapy 1, 6
• Avoid unnecessarily long treatment courses (>7 days for uncomplicated UTI) 1
• Do not obtain cystoscopy or upper tract imaging routinely for recurrent UTI 1