22nd May 2024

Urinary Tract Infections

Background

Urinary tract infections (UTIs) can be classified into lower, upper (i.e. pyelonephritis) and catheter associated UTIs. Antibiotic management differs for each class and between men, non-pregnant women and in pregnancy. Initial investigations and additional management do not differ between groups. Initial investigations include obtaining a urine sample for urine dipstick and laboratory microscopy, culture and sensitivities. Additional management includes pain relief and ensuring the intake of sufficient fluids. There has been no evidence found for cranberry products or urine alkalinising agents to treat lower UTIs. All antibiotics should be reviewed when sensitivities are available, adjusting if resistance is present.

Asymptomatic bacteriuria is significant levels of bacteria in urine with no UTI symptoms. It is not screened for or treated in non-pregnant women, men, children or young people. For pregnant people, it is screened for and treated as it is a risk factor for pyelonephritis and premature delivery.

Catheter-Associated UTI

Catheter-associated UTI is a symptomatic infection of the bladder or kidneys in a person with a urinary catheter. Antibiotic prophylaxis to prevent catheter-associated UTIs is not recommended. Asymptomatic bacteriuria is common in people with catheters. It can be found in almost all catheterised people one month after catheterisation. It, therefore, does not need to be treated if asymptomatic.

Management

Remove, or if not possible, change the catheter if it has been in situ for less than 7 days.
Give oral antibiotics as a first-line if people can take oral medicines and the severity of their condition does not require intravenous antibiotics.
Give IV antibiotics if vomiting, unable to take oral antibiotics or severely unwell. Review intravenous antibiotics within 48 hours and consider stepping down to oral antibiotics where possible

Upper UTI

	First line	Second line
Non-pregnant women and men	Oral – Nitrofurantoin MR 100mg BD for 7 days OR Trimethoprim 200mg BD for 7 days IV – Ceftriaxone 1 to 2g OD or ciprofloxacin 400mg BD/TDS OR Co-amoxiclav 1.2g TDS in culture showing sensitivity	Oral – Pivmecillinam (a penicillin) 400 mg initial dose, then 200 mg three times a day for a total of 7 days IV – consult local microbiologist
In pregnancy	Oral – Cefalexin 500mg BD/TDS for 7 to 10 days IV – cefuroxime 750mg to 1.5g TDS/QDS	Consult local microbiologist
Has upper UTI symptoms	Cefalexin 500 mg BD/TDS for 7 to 10 days OR Co-amoxiclav (only if culture shows susceptibility) 500/125 mg TDS for 7 to 10 days OR Trimethoprim (only if culture shows susceptibility) 200 mg BD for 14 days	Consult local microbiologist

First line

Second line

Non-pregnant women and men

Oral – Nitrofurantoin MR 100mg BD for 7 days OR Trimethoprim 200mg BD for 7 days

IV – Ceftriaxone 1 to 2g OD or ciprofloxacin 400mg BD/TDS

OR Co-amoxiclav 1.2g TDS in culture showing sensitivity

Oral – Pivmecillinam (a penicillin) 400 mg initial dose, then 200 mg three times a day for a total of 7 days

IV – consult local microbiologist

In pregnancy

Oral – Cefalexin 500mg BD/TDS for 7 to 10 days

IV – cefuroxime 750mg to 1.5g TDS/QDS

Consult local microbiologist

Has upper UTI symptoms

Cefalexin 500 mg BD/TDS for 7 to 10 days

OR Co-amoxiclav (only if culture shows susceptibility) 500/125 mg TDS for 7 to 10 days

OR Trimethoprim (only if culture shows susceptibility) 200 mg BD for 14 days

Consult local microbiologist

Lower UTI

Lower UTI (cystitis) is a bladder infection usually caused by bacteria travelling up to the urethra from the gastrointestinal tract. Management involves antibiotics and symptomatic management as described in ‘Background’.

	First line	Second line (no symptomatic improvement on first line for at least 48 hours)
Non-pregnant women	Nitrofurantoin MR 100 mg BD for 3 days (use only if eGFR ≥45) OR Trimethoprim 200 mg twice a day for 3 days	Pivmecillinam (a penicillin) 400 mg initial dose, then 200 mg three times a day for a total of 3 days
Men	Nitrofurantoin MR 100 mg BD for 7 days (use only if eGFR ≥45) OR Trimethoprim 200 mg twice a day for 7 days	Consider alternative diagnoses such as pyelonephritis and prostatitis Change antibiotic to culture and sensitivity results
In pregnancy	Nitrofurantoin MR 100 mg twice a day for 7 days (avoid at term)	Cefalexin 500mg BD 7 days OR Amoxicillin 500mg TDS for 7 days if culture results show susceptibility

First line

Second line (no symptomatic improvement on first line for at least 48 hours)

Non-pregnant women

Nitrofurantoin MR 100 mg BD for 3 days (use only if eGFR ≥45)

OR Trimethoprim 200 mg twice a day for 3 days

Pivmecillinam (a penicillin) 400 mg initial dose, then 200 mg three times a day for a total of 3 days

Men

Nitrofurantoin MR 100 mg BD for 7 days (use only if eGFR ≥45)

OR Trimethoprim 200 mg twice a day for 7 days

Consider alternative diagnoses such as pyelonephritis and prostatitis

Change antibiotic to culture and sensitivity results

In pregnancy

Nitrofurantoin MR 100 mg twice a day for 7 days (avoid at term)

Cefalexin 500mg BD 7 days

OR Amoxicillin 500mg TDS for 7 days if culture results show susceptibility

References

National Institute for Health Care Excellence. Urinary tract infection (lower): antimicrobial prescribing. London: NICE; 2018.(NICE Guideline No. 109). Available from: https://www.nice.org.uk/guidance/ng109
National Institute for Health Care Excellence. Urinary tract infection (catheter associated): antimicrobial prescribing. London: NICE; 2018.(NICE Guideline No. 113). Available from: https://www.nice.org.uk/guidance/ng113
National Institute for Health Care Excellence. Urinary tract infections in adults. London: NICE; 2015. (NICE Guideline No. qs90). Available from: https://www.nice.org.uk/guidance/qs90

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