Ep 77 – Recurrent urinary tract infection

In this podcast, Dr Kate Chesterman discusses recurrent urinary tract infection (UTI). She covers the pathophysiology, some risk factors for UTI recurrence and treatment options including lifestyle changes and the use of antimicrobials. She also focuses on non-antimicrobial management, including the current advice regarding the use of probiotics, cranberry products, D-mannose and methenamine hippurate.

Key references:

1. Ala-Jaakkola R, et al. Nutr J. 2022 Mar;21(1):18. doi: 10.1186/s12937-022-00769-x.
2. Scholes D, et al. 2000 Oct;182(4):1177–82. doi: 10.1086/315827.
3. Urinary tract infection (recurrent): antimicrobial prescribing [NG112]. 31 October 2018.
4. Scottish Antimicrobial Prescribing Group (SAPG). Management of recurrent urinary tract infection (UTI) in non-pregnant women. March 2021.
5. Hoffmann T, et al. BMJ2022 Mar;376:o533. doi: 10.1136/bmj.o533.
6. Gupta K, Trautner B. 2013 May;346:f3140. doi: 10.1136/bmj.f3140.
7. BMJ Best Practice. Urinary Tract Infections in Women. 29 May 2023.
8. NHS West Suffolk CCG and West Suffolk NHS Foundation Trust. Recurrent urinary tract infections. February 2018.
9. Gloucestershire Hospitals NHS Foundation Trust. Patient information: Urinary tract infection. April 2021.
10. Nottinghamshire Area Prescribing Committee. Guidelines for recurrent urinary tract infection in adults: antibiotic prophylaxis. 17 November 2022.

Key take-home points

• Recurrent UTI is generally defined as 2 episodes of UTI in 6 months or 3 episodes within 12 months.
• In patients with recurrent UTI, it is important to send a urine culture.
  • This helps to confirm the diagnosis and allow a pattern of bacteria to emerge, which helps to guide antibiotic and other therapies.
• Other possible primary care investigations for recurrent UTIs (especially in those who have not responded to simple measures) include an ultrasound of the renal tract to detect stones, cysts, tumours and other abnormalities.
  • Can also measure the post-void bladder residual volume to detect voiding dysfunction.
• Lifestyle advice to try to reduce recurrence includes:
  • Voiding before and after intercourse and the avoidance of spermicides
  • Drinking at least 1.5 L of fluid per day
  • Avoiding soaps, shower gels and intimate hygiene products and limiting the washing of the vaginal area to once a day
  • Avoiding constipation
  • Treating incontinence.
• Probiotics do not show benefit over placebo and are not routinely recommended.
• There is limited evidence for the use of cranberry products, but because of the low risk of harm, they are often recommended by urologists.
  • Cranberry tablets may be more practical than cranberry juice.
  • Cranberry products have a high sugar content so need to be used with caution in diabetic patients.
  • Cranberry products are contraindicated in those taking warfarin.
• D-mannose, a monosaccharide that is naturally found in fruits, is increasingly marketed as a pure ingredient in dietary supplements for reducing the risk for UTIs.
  • It can be purchased over the counter.
  • It inhibits E. coli from attaching to urothelium and causing infection; research suggests actual rates of reductions as high as 45% at 6 months.
• Methenamine hippurate (Hiprex) is a urinary antiseptic.
  • A recent study published in the British Medical Journal concluded that Hiprex was as effective in preventing recurrent UTI as prophylactic antibiotics over a 12-month period.
• Topical oestrogens may have an important role in the management of recurrent UTIs in post-menopausal women.
  • Low oestrogen levels have been linked to low numbers of lactobacilli, a rise in vaginal pH and increasing colonisation with uropathogens.
  • Randomised controlled trials comparing topical oestrogen with placebo showed a significant reduction in UTI episodes per patient, per year (from 5.9 in the placebo group down to 0.5 in the topical oestrogen group).
• Antibiotic use should be reserved for when the above treatments have not been effective, have not been tolerated, or are felt to be inappropriate. They can also be considered for recurrent non-E. coli UTIs that may be less susceptible to some of the other treatment options.
• Antibiotics can be used in several ways:
  • Patients could have a short course of narrow-spectrum antibiotics at home, so that they can self-start at the first sign of an infection to try to reduce the severity of the attack.
  • Those whose attacks have a clear trigger (such as intercourse), may benefit from a single dose of antibiotic (e.g., a single dose of 200 mg trimethoprim or 100 mg nitrofurantoin taken within an hour of intercourse).
• Longer-term antibiotic use is only recommended for those who continue to have infections despite lifestyle and non-antibiotic options, and in whom single-dose antibiotic prophylaxis has not been effective or is not appropriate, maybe because that patient doesn’t have identifiable triggers.
  • The usual recommended duration of use is 3–6 months, with a maximum duration of 12 months.
  • 50% of patients will not continue to suffer with recurrent UTIs after stopping prophylaxis.