Infectious disease specialist and clinical microbiologist Dr Jonathan Chambers was one of the doctors who was consulted by WA Health before the decision was made to go ahead with the pharmacy prescribing trial. This is his take.
Uncomplicated Urinary Tract Infection (UTI): It’s complicated!
There is no consistent agreed definition of an uncomplicated urinary tract infection. An uncomplicated UTI generally refers to an infection that occurs in the lower urinary tract (bladder and urethra) of pre-menopausal adult women, without any evidence of systemic infection, pyelonephritis (or history of pyelonephritis/urosepsis), pregnancy, underlying complicating medical condition or recurrent urinary tract infections.
This type of UTI is characterised by mild to moderate symptoms localised to the lower urinary tract, such as dysuria, frequency, urgency, and suprapubic discomfort. It occurs in otherwise healthy individuals and is typically caused by Escherichia coli (E.coli) in approximately +90% of cases.
Many these patients will recover with no antibiotic therapy. However, a proportion may go on to develop a complicated infection which may be prevented with antibiotics.
Antibiotics
Empiric antibiotic recommendations for uncomplicated UTI reflect the prevailing patterns of E.coli resistance in the community. This typically aims for an effective antibiotic >80% of the time based on prevailing resistance patterns.
At present in Western Australia, Nitrofurantoin remains susceptible in roughly 90-95% of cases. Nitrofurantoin given in short courses 100mg PO QID for five days (or as directed by international/national/local guidelines) for uncomplicated urinary tract infections in healthy premenopausal adult women is safe and effective.
Unlike other antibiotics there is minimal impact on the patients commensal flora outside of the urinary tract, low rates of C.difficile and similar rates of severe adverse drug reactions compared to other antibiotics. Importantly this is arguably the cheapest and best antibiotic to use to preserve our other critical antimicrobials for other more severe infections.
Alternatives such as Trimethoprim are no longer testing reliably susceptible >80 % of the time in the local context for E.coli. Whilst it is still recommended in Australian guidelines this may not continue without certain caveats.
I believe it is important to perform urine culture and susceptibilities in patients in whom this drug is used to confirm it is likely to be effective. Antibiotics like ciprofloxacin, norfloxacin, amoxicillin/clavulanic acid, and cephalexin aren’t recommended first-line due to being overly broad spectrum with a similar efficacy for uncomplicated UTIs.
Investigation/Management:
- Patient history: Gather information about the patient’s symptoms, medical history, current medications, allergies, recent sexual activity, and any previous UTIs.
- Physical examination: Conduct a quick physical examination to assess for signs of infection and any abnormalities in the genital and urinary areas.
- Urine sample: Collect a midstream urine sample for urinalysis and urine culture to confirm the presence of infection and identify the causative organism.
Urine dipstick and culture aid the diagnosis. It is this author’s opinion that a positive urine is required to diagnose a urinary tract infection in the context of compatible symptoms. Negative results suggest alternative diagnoses, like Mycoplasma genitalium or Chlamydia/Gonococcal-associated urethritis or even sinister non-infective causes. Accurate antibiotic susceptibility data is crucial for optimal future empirical recommendations. It will also identify other common urinary pathogens that may require different approaches.
Non-Antibiotic Therapy:
- Avoid dehydration in addition to Increasing fluid intake to maintain clear and frequent urination
- Simple analgesics such as ibuprofen or paracetamol
- There is minimal high-quality evidence to recommend cranberry supplements, urinary alkalinisation (contraindicated with Nitrofurantoin) and probiotics
Follow-Up:
If symptoms persist or worsen, consider further investigation to rule out underlying complications. If that patient becomes unwell with fevers and/or severe back pain and/or Nausea/vomiting may need referral to an emergency department for parenteral therapy.