What is the best antibiotic agent for urinary tract infections (UTIs) in men?

Best Antibiotic Agent for UTI in Men

For men with urinary tract infections, trimethoprim-sulfamethoxazole (160/800 mg twice daily) for 14 days is the first-line antibiotic choice, with fluoroquinolones (ciprofloxacin 500-750 mg twice daily or levofloxacin 750 mg once daily) reserved for 7-14 days when local resistance to TMP-SMX exceeds 10% or when TMP-SMX cannot be used. 1

Why Men Require Different Treatment Than Women

• All UTIs in men are classified as complicated infections due to anatomical and physiological factors, requiring longer treatment duration (14 days) compared to uncomplicated UTIs in women 1
• The 14-day duration is necessary because prostatitis cannot be excluded in most initial presentations, and inadequate treatment duration leads to persistent or recurrent infection 1
• The microbial spectrum in male UTIs is broader than in uncomplicated UTIs, with increased likelihood of antimicrobial resistance including E. coli, Proteus species, Klebsiella species, Pseudomonas species, and Enterococcus species 1

First-Line Oral Antibiotic Options

Trimethoprim-Sulfamethoxazole (Preferred)

• TMP-SMX 160/800 mg twice daily for 14 days is the first-line choice as it effectively targets common uropathogens including E. coli, Klebsiella, Enterobacter, and Proteus species 1
• This should be used when local resistance rates are acceptable and the patient has no allergy 1

Fluoroquinolones (Alternative First-Line)

• Ciprofloxacin 500-750 mg twice daily for 7-14 days is recommended only when local resistance is <10% 2, 3
• Levofloxacin 750 mg once daily for 5-7 days is an alternative fluoroquinolone option 2, 3
• Fluoroquinolones should be avoided when other effective options are available, especially in cases of allergy 1
• A 5-day course of levofloxacin 750 mg has been shown to be as effective as 10-day courses in males with UTI 4

Oral Cephalosporins (Second-Line)

• Cefpodoxime 200 mg twice daily for 10 days is an alternative if TMP-SMX cannot be used or if resistance is suspected 2, 1
• Ceftibuten 400 mg once daily for 10 days is another oral cephalosporin option 2, 1
• Cefuroxime 500 mg twice daily for 10-14 days can be used for step-down therapy 2

When to Consider Shorter Duration (7 Days)

• A shorter treatment duration of 7 days may be considered if the patient becomes afebrile within 48 hours and shows clear clinical improvement 5, 1
• However, recent evidence from a subgroup analysis showed that 7-day ciprofloxacin therapy was inferior to 14-day therapy for short-duration clinical cure in men with complicated UTI (86% vs. 98%) 5
• The safest approach is to default to 14 days unless there is rapid clinical response and prostatitis can be confidently excluded 1

Parenteral Options for Severe or Resistant Infections

When to Use IV Antibiotics

• High fever with chills requires intensive treatment with IV antibiotics until subsidence of acute symptoms, followed by oral antibiotics for two weeks 6
• Multidrug-resistant organisms require parenteral therapy initially 2

Parenteral Antibiotic Choices

• Carbapenems: Imipenem/cilastatin 0.5 g three times daily, meropenem 1 g three times daily, or meropenem-vaborbactam 2 g three times daily 2
• Newer β-lactam/β-lactamase inhibitor combinations: Ceftolozane/tazobactam 1.5 g three times daily, ceftazidime/avibactam 2.5 g three times daily, or cefiderocol 2 g three times daily 2
• Aminoglycosides: Gentamicin 5 mg/kg once daily, amikacin 15 mg/kg once daily, or plazomicin 15 mg/kg once daily, especially with prior fluoroquinolone resistance 2

Essential Management Steps

Before Starting Antibiotics

• Always obtain urine culture before initiating antibiotic therapy to guide potential adjustments based on susceptibility results 1
• Failing to obtain urine culture before starting antibiotics complicates management if initial empiric therapy is ineffective 1

After Treatment

• Obtain follow-up urine culture after completion of therapy to ensure resolution of infection 2
• Address potential underlying urological abnormalities that may contribute to infection or recurrence 1

Common Pitfalls to Avoid

• Do not use fluoroquinolones as first-line when TMP-SMX is effective, as fluoroquinolone resistance is increasing in many regions 1, 7
• Do not treat for less than 7 days unless there is exceptional clinical response, as inadequate duration leads to recurrence 1
• Do not assume 5-day courses are adequate without clear evidence of rapid clinical improvement and absence of prostatic involvement 5
• Do not fail to consider prostatitis in the differential, as this requires longer treatment (14-42 days for category I-IIIA inflammatory prostatic disease) 6