Urinary Tract Infection

Acute Simple Cystitis

General points

• Symptoms confined to the lower urinary tract such as dysuria, frequency, urgency, suprapubic pain.
• Urine culture should be performed on all hospitalized patients before starting antibiotics.
• Review previous urine culture results prior to prescribing.
• Bacterial growth in urine culture in the absence of clinical features of infection ( asymptomatic bacteriuria ) does not warrant antimicrobial treatment. Exceptions to this are pregnancy and patients due to undergo a urological procedure where mucosal injury is anticipated.
• A positive urine dipstick result in an asymptomatic patient is not significant and should not be treated.

Antibiotics (Empiric Therapy)

Nitrofurantoin (Immediate Release Capsules)* 50mg QDS PO

OR

Nitrofurantoin (Prolonged Release Capsules) 100mg BD PO

OR

Cephalexin 500mg BD PO

Alternative: Trimethoprim 200mg BD x 3 days ONLY if recent urinary isolate has tested susceptible. Trimethoprim is contraindicated in pregnancy.

* Nitrofurantoin should not be used in patients with severe renal impairment (CKD stage 4/5, eGFR <30mL/min/1.73m ² , Creatinine Clearance <30 ml/min) as it does not achieve sufficient levels in the urine to be of therapeutic benefit. There is also an increased risk of toxicity. Nitrofurantoin may be used with caution (as short-course therapy only) if there is a lesser degree of renal impairment (eGFR greater than 30 mL/min) to treat suspected or proven resistant pathogens, when the benefits are expected to outweigh the risks. Caution is advised in older patients with poor fluid intake as renal function may deteriorate in the setting of infection.

In pregnancy nitrofurantoin may also be used but it should be avoided at term.

Nitrofurantoin is also contraindicated in G6PD deficiency.

Duration:

Non-pregnant females =3 days.

Men = 7 days if no concern for prostatic involvement.

Acute Complicated UTI including Pyelonephritis

General points

• Symptoms of upper urinary tract infection include fever, rigors, flank and loin pain/tenderness, nausea and vomiting.
• Send MSU/CSU and blood cultures before staring antibiotics if possible.
• Review previous microbiology test results, in particular MSU/CSU cultures for resistance profiles of suspected Gram negative pathogens such as E. coli, Klebsiella spp. and for MDROs such as ESBL-producers or CPE - Discuss with microbiology if required.
• Assess for sepsis and follow relevant protocols if applicable.
• Obstruction of the urinary tract is the most frequent urological source of urosepsis.
• Consider urgent renal tract imaging to assess as indicated. If identified, decompression of obstruction, drainage of abscesses, and removal of foreign bodies such as urinary catheters or stones as source control strategies are crucial.

Antibiotics (Empiric therapy)

First line:

Piperacillin-tazobactam 4.5g TDS/QDS IV (QDS dosing indication: severe infection, neutropenic sepsis or Pseudomonas aeruginosa infection)

+ * Gentamicin once daily IV single dose. (Please see Gentamicin dosing schedule)

NOT-IgE-mediated /anaphylaxis/severe penicillin allergy :

Ceftriaxone 2g once daily IV + * Gentamicin once daily IV single dose. (Please see Gentamicin dosing schedule) .

IgE-mediated /anaphylaxis/ severe penicillin allergy :

Ciprofloxacin** 400mg BD IV + * Gentamicin once daily IV single dose. (Please see Gentamicin dosing schedule) .

If history of ESBL -producing gram negative bacteria use Meropenem 1g TDS IV. Restricted agent, discuss with Clinical Microbiologist.

*In severe illness, septic shock or if history of infection/colonisation with gentamicin resistant gram negative bacteria use Amikacin once daily single dose (max dose 1.5g) instead of gentamicin. (Please see Amikacin dosing schedule) .

** Please read the HPRA Drug Safety Alert issued in 2018 and the HPRA Drug Safety Newsletter issued in 2023 highlighting restrictions on use of fluoroquinolones (eg. ciprofloxacin, levofloxacin) due to the risk of disabling, long-lasting and potentially irreversible side effects (including tendon damage, QT prolongation, neuropathies and neuro psychiatric disorder). Use of fluoroquinolones in older patients, those with renal impairment, solid organ transplantation or on systemic corticosteroids increases the risk of tendon damage.

Comments

• Stop aminoglycoside when patient stable or if identified pathogen tests susceptible to primary antibiotic. Single dose only may be required. Treatment beyond 3 days is rarely indicated.
• Review antimicrobials at 24-48h with urine and blood culture and susceptibility test results to ensure pathogens identified are susceptible to antibiotics prescribed.
• De-escalate to narrower spectrum agent if possible.
• Consider renal tract imaging to investigate for obstruction or structural abnormality, in particular if clinical improvement is slow.
• Switch to oral agent if available when suitable.
• Nitrofurantoin is NOT suitable for the treatment of pyelonephritis or systemic infection as it does not achieve tissue and blood levels sufficient for these indications.
• Duration: 7-10 days is usually sufficient. Longer courses 10-14 days may be required in those with a slow clinical response and suboptimal or delayed source control, if applicable.

Catheter-Associated UTI

General points

• Asymptomatic bacteriuria or catheter colonisation is common in those with indwelling catheters and is by itself not an indication for antimicrobial therapy.
• Do not carry out routine urine culture in catheterised patients with no clinical features of infection.
• Pyuria is a common finding in catheterized patients with bacteriuria, whether they are symptomatic (i.e. have UTI) or not. Do not use pyuria as sole indicator for catheter-associated UTI.
• Do not use the presence of malodorous or cloudy urine alone to diagnose catheter-associated UTI.
• Take a urine culture prior to initiating antimicrobial therapy in patients where the catheter has been recently removed and infection is clinically suspected.

Antibiotics (Empiric therapy)

If clinical features of systemic infection or pyelonephritis: see Acute Complicated UTI including pyelonephritis section.

Remove indwelling catheter if possible.

If long term catheterization is required, replace urinary catheter at the start of antimicrobial treatment to prevent early relapse of infection.

Acute Prostatitis

General points

• Send urine specimen for culture prior to treatment.
• Consider testing for chlamydia and gonorrhoea.

Antibiotics (Empiric therapy)

1st line:

* Ciprofloxacin 500mg-750mg BD PO

OR

Trimethoprim (if ciprofloxacin not suitable) 200mg BD

OR

Co-trimoxazole (Trimethoprim-sulfamethoxazole) 960mg BD PO

* Please read the HPRA Drug Safety Alert issued in 2018 and the HPRA Drug Safety Newsletter issued in 2023 highlighting restrictions on use of fluoroquinolones (e.g. ciprofloxacin, levofloxacin) due to the risk of disabling, long-lasting and potentially irreversible side effects (including tendon damage, QT prolongation, neuropathies and neuro psychiatric disorder). Use of fluoroquinolones in older patients, those with renal impairment, solid organ transplantation or on systemic corticosteroids increases the risk of tendon damage.

Comments

Duration: Review antibiotics after 14 days and either stop or continue for a further 14 days based on clinical assessment and culture results.

Treatment for 4 weeks may prevent chronic prostatitis but it is difficult to predict those at risk.

Review urine C&S results to ensure pathogen susceptible to prescribed agents.