Uncomplicated Acute Lower Urinary Tract Infections (Cystitis) in Women

• See investigation and treatment guidelines in Hospital HealthPathways.
• An uncomplicated UTI is one that occurs in a female with a normal urinary tract and normal renal function, who is not catheterised and not immunosuppressed.
• Asymptomatic bacteriuria – does not usually require treatment except in pregnancy – see separate section below.

Pathogens

• Uncomplicated community acquired: E. coli, S. saprophyticus, Proteus mirabilis
• Consider risk factors for multidrug resistant Gram-negative bacilli (MDR-GNB), such as extended spectrum beta-lactamase (ESBL) producers. If risk factors, ensure urine is sent for culture and susceptibility testing before initiating antimicrobial therapy. If empiric treatment is needed before results are available, use nitrofurantoin.
  • recent admission to overseas healthcare facility
  • multidrug-resistant Gram-negative bacilli positive
  • travel to developing country in previous six months
  • household contact with MDR-GNB
  • residence or admission to any facility with high prevalence of MDR-GNB
  • broad spectrum antimicrobial treatment

Drug Treatment

• Susceptibilities from urine samples (when done) to guide oral treatment are usually available within 24 hours.
• Duration: 3 to 5 days

Empiric

Non-pregnant Patients

nitrofurantoin HMLSchedNZFPML Nitrofurantoin F: 0.9 Half life: 1 hour Elimination: reduction fe: 0.5 Additional points: Modified-release capsules have longer duration of action. Do not crush or chew the modified-release dose form.

PO 100 mg (modified-release) two times a day for 5 days

• Include "modified release" or the brand name ("Macrobid") in the prescription to minimise incorrect selection of the immediate release nitrofurantoin product that requires four times daily dosing.
• Metabolised by unknown pathways. (fe = 0.5).
• Avoid with creatinine clearance < 30 mL/min as it may not reach effective concentrations in the urine and there may be increased adverse effects. If creatinine clearance is 30–60 mL/min, a short course (5 days) of nitrofurantoin may be considered for some patients (e.g. with multi-resistant organisms). Alternative options are often available – discuss with Infectious Diseases/Clinical Microbiology before prescribing.
• Ineffective for Proteus species.

OR

cefalexin HMLSchedNZFPML Cefalexin F: 0.9 Half life: 1 hour Elimination: renal fe: 0.9

PO 500 mg twice a day for 5 days

• fe = 0.9, dose is not normally reduced in patients with reduced CrCl for UTI treatment because it is the urinary concentrations that are important.

OR

trimethoprim HMLSchedNZFPML Trimethoprim F: 1 Half life: 10 hours Elimination: renal fe: 0.7

PO 300 mg once a day for 3 days

• Avoid if used in the previous 6 months due to increased likelihood the causative organism will be resistant to trimethoprim.
• fe = 0.7, dose is not normally reduced in patients with reduced CrCl for UTI treatment because it is the urinary concentrations that are important.

Pregnant Patients

• Asymptomatic bacteriuria and symptomatic cystitis should be treated.
• Empiric treatment options are as for non-pregnant women, except that cefalexin should be considered first-line. Nitrofurantoin is second line (not when labour is imminent – risk of haemolysis in the neonate) and trimethoprim is third-line (not in the first trimester as is a folate antagonist).

Pathogen Known (with symptoms)

Enterococci

amoxicillin HMLSchedNZFPMLnoids Amoxicillin F: 0.9 Half life: 2 hours Elimination: renal fe: 0.9

PO 500 mg three times a day for 5 days

• fe = 0.9, dose is not normally reduced in patients with reduced CrCl for UTI treatment because it is the urinary concentrations that are important.

OR

• Include "modified release" or the brand name ("Macrobid") in the prescription to minimise incorrect selection of the immediate release nitrofurantoin product that requires four times daily dosing.
• Metabolised by unknown pathways. (fe = 0.5).
• Avoid with creatinine clearance < 30 mL/min as it may not reach effective concentrations in the urine and there may be increased adverse effects. If creatinine clearance is 30–60 mL/min, a short course (5 days) of nitrofurantoin may be considered for some patients (e.g. with multi-resistant organisms). Alternative options are often available – discuss with Infectious Diseases/Clinical Microbiology before prescribing.
• Avoid in pregnancy when labour is imminent - risk of haemolysis in the neonate.

Extended-spectrum beta-lactamase (EBSL) producing coliforms

Most ESBL producing E. coli are susceptible to:

• Include "modified release" or the brand name ("Macrobid") in the prescription to minimise incorrect selection of the immediate release nitrofurantoin product that requires four times daily dosing.
• Metabolised by unknown pathways. (fe = 0.5).
• Avoid with creatinine clearance < 30 mL/min as it may not reach effective concentrations in the urine and there may be increased adverse effects. If creatinine clearance is 30–60 mL/min, a short course (5 days) of nitrofurantoin may be considered for some patients (e.g. with multi-resistant organisms). Alternative options are often available – discuss with Infectious Diseases/Clinical Microbiology before prescribing.
• Avoid in pregnancy when labour is imminent - risk of haemolysis in the neonate.

If organism is not susceptible to nitrofurantoin or patient is unsuitable for nitrofurantoin:

• Not funded on discharge – ask your ward pharmacist to supply on discharge.

OR

• Not funded on discharge – ask your ward pharmacist to supply on discharge.

Topic Code: 99242

must be prescribed or recommended by a consultant.