Urinary tract infections

For comprehensive details on the diagnosis of urinary tract infections please refer to the algorithms and diagnosis guidelines from Public Health England.

The Patient Urinary Tract Infection (UTI) Information leaflet has been designed to be used during consultation with women who are experiencing non complicated UTIs. It is a useful tool for clinicians to use where the clinician feels that the patient does not require an antibiotic prescription. It includes information on illness duration, self-care advice, prevention advice and advice on when to re-consult.

The Patient Urinary Tract Infection (UTI) Information Leaflet

Asymptomatic bacteriuria

Asymptomatic bacteriuria in non-pregnant adults does not need to be treated, even with a positive urine dip. Treating does NOT reduce mortality, UTI rates, carriage or improve incontinence.

Note: In line with NICE CKS asymptomatic bacteriuria in pregnancy should always be confirmed with a second sample and if persisting then treated.

UTI in adults (no fever or flank pain)

For mild UTI symptoms with no fever or flank pain, advise patient to drink plenty of fluids, take analgesia and only use antibiotics if symptoms do not improve after 48 hours. Consider a back-up / delayed antibiotic option

Always ensure safety netting information is given as resistance is common and patients should re-consult if symptoms remain after 48hrs or they develop systemic symptoms. Possible signs of serious infection can be found in the Public Health England UTI leaflet (Please see the Patient Urinary Tract Infection information leaflet above).

Always check past microbiology results for a history of resistance and sensitivities before prescribing empirical antimicrobial therapy and always send a urine culture in treatment failures.

If 3 or more infections in the last 12 months, or 2 in the last 6 months, then follow the recurrent UTI guidance below.

Consider chlamydia if symptoms of UTI but negative cultures.

Refer to Public Health England guidelines to decide whether antibiotic treatment is appropriate.

  • 100mg m/r capsule every 12 hours, for 3 days in women and 7 days in men
  • Use nitrofurantoin first-line as general resistance to trimethoprim is increasing.
  • Nitrofurantoin should not be used to treat UTI with systemic symptoms or for suspected upper tract infections as therapeutically active concentrations are only achieved in the urine
  • Short courses not associated with pulmonary fibrosis
  • MHRA Drug Safety Update (September 2014):
    • Nitrofurantoin should be avoided in patients with an estimated glomerular filtration rate (eGFR) of less than 45 ml/min, due to lack of efficacy rather than toxicity
    • Nitrofurantoin should not be used to treat sepsis syndrome secondary to urinary tract infection or suspected upper urinary tract infections
    • A short course (3 to 7 days) may be used with caution in certain patients with an eGFR of 30 to 44 mL/min. Only prescribe to such patients to treat lower urinary tract infection with suspected or proven multidrug resistant pathogens when the benefits of nitrofurantoin are considered to outweigh the risks of side effects
    • Consider checking renal function when choosing to treat with nitrofurantoin, especially in the elderly
    • Closely monitor for signs of pulmonary, hepatic, neurological, haematological, and gastrointestinal side effects during treatment
  • 200mg every 12 hours, for 3 days in women and 7 days in men
  • Use trimethoprim only if low risk of resistance (e.g. younger women with acute UTI and no other risk factors)
  • Risk factors for increased resistance include: care-home resident; recurrent UTI; hospitalisation for >7 days in the last 6 months; unresolving urinary symptoms; recent travel to a country with increased resistance; previous UTI resistant to trimethoprim, cephalosporins, or quinolones
If eGFR less than 45ml/min, consider
  • Initially 400mg for one dose, then 200mg every 8 hours for 3 days in women, 7 days in men
  • This is an extended-spectrum penicillin antibiotic

Community multi-resistant UTIs

If released on a urine sensitivity report then consider the following i.e. not for empirical use
  • Initially 400mg for one dose, then 200mg every 8 hours for 3 days in women, 7 days in men
  • This is an extended-spectrum penicillin antibiotic
If high risk of resistance


  • Female: 3g sachet as a single dose (dose may be repeated in complicated UTI; unlicensed)
  • Male: 3g sachet initial dose and repeat after 3 days (unlicensed but in line with PHE guidance)
  • Doses should be taken preferably before bedtime and after emptying the bladder

Catheter associated urinary tract infection (CA-UTI)

Diagnosis of catheter associated urinary tract infection (CA-UTI) is based on clinical signs. Asymptomatic catheterised patients with cloudy or crystalline urine, debris in urine, discomfort or bypassing of the catheter do not require treatment for infection.

Patients with indwelling urinary catheters almost invariably have abnormalities on dipstick testing including nitrite, leucocyte esterase, blood and protein. Similarly bacteriuria is present in most patients with urinary catheters. Only send a CSU if patient has symptoms of systemic infection such as fever, new onset of confusion, supra-pubic tenderness. See also local pathways on diagnosis and management of CA-UTI.

When a sample for culture is indicated, include clinical details.

Urinary catheters which have been inserted for more than one week should be replaced during the course of antibiotics, if there is a clinically important UTI.

Antibiotic prophylaxis can be considered when catheters are changed if there is current infection, or a history of UTI associated with catheter change. Consider, 80mg IM gentamicin just prior to catheterisation.

Acute prostatitis

Always send MSU for culture and start antibiotics. Quinolones achieve higher prostate levels.

4 weeks treatment may prevent chronic prostatitis. Review treatment after 14 days and consider accuracy of original diagnosis if no improvement.

  • 500mg every 12 hours for 28 days
  • 200mg every 12 hours for 28 days

UTI in pregnancy

For more information on drugs in pregnancy refer to the UKTIS maternal exposure summary documents

Take an MSU for culture & sensitivities. Immediately start antibiotics then review when results are known.

Test urine culture 7 days after completion to confirm cure. In cases of asymptomatic bacteruria in pregnancy: two positive samples are required before treatment is initiated.

1st / 2nd trimester
  • 100mg m/r capsule every 12 hours for 7 days
  • Not suitable if there is evidence of upper tract infection e.g. loin pain.
  • The Public Health England advice is that short-term use of nitrofurantoin in pregnancy is unlikely to cause problems to the foetus
2nd / 3rd trimester
  • 200mg every 12 hours for 7 days
  • Public Health England recommends avoiding trimethoprim if patient has low folate status or is on a folate antagonist (e.g. antiepileptic or proguanil)
Upper urinary tract infection
  • 500mg every 8 hours for 7 days
  • Or in any trimester if the above options are not suitable

UTI in children

Refer to NICE CG54: Urinary tract infection in under 16s: diagnosis and management (August 2007) for further information

Child younger than 3 months: refer urgently for assessment. Refer any child with features of upper UTI / pyelonephritis.

Child 3 months or older: use positive nitrite to start antibiotics. Send pre-treatment MSU for all.

Imaging: only refer if child under 6 months old, recurrent or atypical UTI

Lower UTI


Upper UTI


Acute pyelonephritis

An MSU must be sent and then empirical treatment initiated. Be guided by previous MSUs (if available) for evidence of resistance.

Review treatment choices when antibiotic results available.

Depending on severity / systemic symptoms consider referral to hospital. Also, if no response within 24 hours consider referral.

  • 500mg every 6 hours for 7 days
  • 500mg every 12 hours for 7 days

Sensitivity testing performed by laboratories reflects and supports local antibiotic guidance.

Recurrent UTI in non-pregnant women, 3 or more UTI in a year (or 2 in 6 months)

A recurrent urinary tract infection is where a woman has 3 or more infections in 12 months (or 2 in 6 months).

Recurrent urinary tract infections require investigation, always send an MSU to guide treatment, and check previous cultures.

Nightly prophylaxis reduces UTIs but adverse effects and long term compliance is poor.

To reduce recurrence, first advise simple measures including hydration, analgesia, cranberry products, and then standby or post-coital antibiotics. Some self-care medicines are available in shops and supermarkets. Please click here for further information and a patient leaflet.

In North Devon, patients with recurrent UTI can be referred to a joint urology / microbiology clinic

First line

Standby antibiotics (as per UTI in adults treatment above).

Patients should be given standby antibiotics based on previous culture results where possible. They should be told to start these antibiotics as soon as they develop symptoms, and to continue until symptoms resolve, or for up to 5 days. If they are not feeling better within 48 hours, or if they have residual symptoms after 5 days, they should be told to return. Patients should be given red top tubes so that they can take a urine culture before the first dose of antibiotics. This is used to define the epidemiology, and to guide treatment in the case of subsequent failure.

Alternative first line (Post coital prophylaxis)
  • 100mg m/r capsule as a single dose post-coital (off label)
  • Maximum 100mg daily
Second line (Antibiotic prophylaxis)
  • 100mg m/r capsule at night for 3-6 months and then review recurrence rate and need for continuation
  • Patients should be monitored closely for sign of pulmonary, hepatic, neurological, haematological and gastrointestinal side effects during treatment
Trimethoprim (if recent culture sensitive)
  • 100mg at night, or as a single dose post-coital (off label), for 3-6 months; then review recurrence rate and need for continuation


Home > Formulary > Chapters > 5. Infections > Urinary tract infections


  • First line
  • Second line
  • Specialist
  • Hospital