Lower Urinary Tract Infection


Coliforms and Enterococcal


Total duration: women 3 days (7 days if catheterised); men 7 days

First Line

Trimethoprim 200mg 12 hourly


Nitrofurantoin M/R 100mg 12 hourly (avoid if CrCl < 40mL/min)

Catheterised patients :

Only treat if systemically unwell or pyleonephritis likely – antibiotics will not eradicate asymptomatic bacteriuria.

Change catheter – only use prophylactic antibiotics in patients with a history of catheter change-associated UTI or trauma (NICE, SIGN).

Send pre-treatment CSU

Start empirical antibiotics


Under 65 years and suspected LUTI

Treat women with severe / ≥ 3 symptoms

Assess women with mild/ ≤ 2 symptoms:

  • Obtain urine specimen and exclude UTI if urine not cloudy or dipstick negative
  • Treat with pain relief
  • Consider delayed (48 hour) prescription


  • Consider prostatitis
  • Send pre-treatment MSU or if symptoms mild/non-specific, use negative dipstick to exclude UTI

In treatment failure, always perform urine culture


Over 65 years

Do not treat asymptomatic bacteruria – it is common but not associated with increased morbidity.


Useful Resources

SAPG: Decision aid for diagnosis and management of suspected urinary tract infection (UTI) in older people

SIGN 88: Management of suspected UTI in non-pregnant women

SIGN 88: Management of suspected UTI in men


Doses may need to be adjusted in renal impairment. Always check BNF for interactions. Seek advice if patient pregnant

Drug specific cautions:

  1. Check interactions in the BNF. Caution may prolong QT interval.
  2. Avoid Doxycycline and Co-trimoxazole if pregnant or breast feeding
  3. Gentamicin/Vancomycin refer to online calculators
  4. ALERT antibiotic needs ALERT form
  5. Monitor sodium
  6. See CURB65 definition
  7. Reference: The Renal Drug Handbook 4th Edition, 2014