(c) Urinary tract

UTI in women and men (no fever/flank pain)
First Choice:
nitrofurantoin 100mg MR twice daily
(women 3 days, men 7 days treatment)
ortrimethoprim (use if low risk of resistance) 200mg twice daily (women 3 days, men 7 days treatment)
Second Choice:
cefalexin 500mg twice daily
Recurrent UTI
First Choice:
advise simple measures incl. hydration and analgesia
Second Choice:
standby or post-coital antibiotics
Third Choice:
antibiotic prophylaxis . Consider methenamine if no renal or hepatic impairment
First Choice:
co–amoxiclav 625mg 3 times daily for 7 days
orciprofloxacin 500mg twice daily for 7 days

If susceptible trimethoprim 200mg twice daily for 14 days.
  • cefalexin tablets 250mg; capsules 250mg.
  • ciprofloxacin tablets 100mg, 250mg, 500mg; suspension 250mg/5mL.
  • co-amoxiclav tablets 375mg, 625mg; suspension 125/31 SF, 250/62 SF.
  • trimethoprim tablets 100mg, 200mg; suspension 50mg/5mL.
  • nitrofurantoin capsules MR 100mg; suspension 25mg/5mL.
  • methenamine tablets 1g.
Prescribing Notes

Uncomplicated urinary-tract infection

  • Nitrofurantoin is contraindicated in patients with an estimated glomerular filtration rate (eGFR) of less than 45 ml/min/1.73m2.  However, a short course (3 to 7 days) may be used with caution in patients with an eGFR of 30 to 44 ml/min/1.73m2.
  • Trimethoprim should be used with caution in patients with eGFR less than 30 ml/min/1.73m2.
  • A transient increase in serum creatinine may occur with trimethoprim treatment.
  • See BNF for dosing instructions for other antibiotics in renal impairment.
  • Asymptomatic bacteriuria does not require treatment, except in pregnancy.
  • A short course of antibiotics, for women with severe/>3 symptoms (dysuria, urgency, frequency, polyuria, suprapubic tenderness, fever, flank or back pain), is usually sufficient for uncomplicated UTIs in women; longer courses may be needed for more complicated infections.
  • Women mild/≤2 symptoms; give pain relief and consider delayed antibiotic.
  • It is always necessary to strive to establish the cause of male UTIs. An MSSU should always be obtained prior to treatment but treatment need not be deferred pending the result.
  • Risk factors for increased resistance include: care home resident, recurrent UTI (2 in 6months; ≥3 in 12 months), hospitalisation for >7 days in last 6 months, unresolving urinary symptoms, recent travel to a country with increased resistance, previous UTI resistant to trimethoprim, cephalosporins or quinolones.

Multi-antibiotic resistant enterobacteriaceae lower urinary tract infections

  • Fosfomycin and pivmecillinam are both approved for the treatment of confirmed multi-antibiotic resistant enterobacteriaceae lower urinary tract infections.  Refer to this flowchart for appropriate choice of agent.


  • Complicated UTI refers to patients with systemic toxicity; haematuria alone does not constitute a complicated UTI.
  • If admission to hospital not required, send MSU for culture and sensitivities and start antibiotics. If no response within 24 hours admit to hospital.
  • If resistance risk from extended spectrum beta lactamase inhibitor (ESBL), with microbiology advice consider IV antibiotic via OPAT service.

Urinary-tract infections in pregnancy

  • Send urine for culture before starting antibiotics; and another 7 days after completion of antibiotics to check for cure.
  • Asymptomatic bacteriuria in pregnancy; confirm culture result with second urine culture before treating.

  • Trimethoprim is not routinely used in the first trimester of pregnancy but can be used with folate.  Avoid this option if low folate status or on a folate antagonist.

  • Avoid nitrofurantoin at term, and do not prescribe during labour; risk of neonatal haemolysis.

Recurrent UTI in non-pregnant women: 2 in 6 months or ≥3 UTIs/year

  • Advise simple measures including hydration and analgesia.
  • Second line, stand by or post-coital antibiotics.
  • For postmenopausal women with risk factors such as atrophic vaginitis, consider prescribing topical oestrogen.
  • Antibiotic prophylaxis may be recommended on specialist advice, recurrence rate and the ongoing need should be reviewed at 3 to 6 months  If no renal or hepatic impairment then methenamine should be considered.

  • Nitrofurantoin should not be used for long term treatments; it has been associated with serious lung and liver adverse effects.

Catheterised patients

  • In catheterised patients, pyuria and bacteriuria are common and do not merit antibiotics; bladder spasm and dysuria are usually catheter associated. Signs and symptoms compatible with catheter-associated UTI include new onset or worsening of fever, rigors, new onset delirium, flank pain; costo-vertebral angle tenderness; acute haematuria; and pelvic discomfort.  The catheter should be changed prior to obtaining CSU and commencing antibiotics. Check CSU to ensure appropriate antibiotics are being given.  If a change of antibiotic is required, ideally change the catheter again.
  • Gentamicin should not be used routinely when catheters are changed.