Design: Retrospective multi-practice audit
Population: 256 adults on recurrent UTI prophylaxis in 18 English practices
Primary outcome: Guideline concordance, six-month review, response to resistant isolates
Effect: 73.6% concordant; 58.1% reviewed in 6 months; 22.9% modified after resistance

An audit across 18 general practices in Leicestershire, published in Family Practice on 31 July 2026, reviewed 256 adults prescribed antibiotic prophylaxis for recurrent urinary tract infection between late 2021 and early 2024. Most were women, with a mean age of 67, and nitrofurantoin and trimethoprim were the usual agents.

Median duration was 2.2 years. About three quarters of regimens matched guidelines, but only 58% were reviewed within six months of starting. A quarter of patients grew a resistant organism, which was linked to more breakthrough infections, yet only 23% of these had their prophylaxis changed. Practices in more deprived areas adhered less well.

This is one region's audit, and it cannot show harm from the lapses. But the pattern is recognisable in any practice: prophylaxis is started at the end of a difficult consultation and then renewed on repeat. A six-month review, a culture with every breakthrough infection and a decision about whether to continue are the fixes. For long-term nitrofurantoin, monitoring for pulmonary and hepatic toxicity and checking renal function also belongs in that review.

Book a review within six months of starting UTI prophylaxis and decide whether to continue.
Send urine for culture with every breakthrough infection on prophylaxis.
Change or stop prophylaxis when the urine isolate is resistant to the agent in use.
Check renal function and ask about breathlessness or cough in patients on long-term nitrofurantoin.
Discuss non-antibiotic options, such as vaginal oestrogen in postmenopausal women, at review.

Why it matters

Antibiotic prophylaxis on repeat prescription is one of primary care's least visible sources of resistance.

The statistics, in plain English

These are audit proportions, not effect sizes: 58% reviewed and 23% modified after resistance are measures of how often standards were met. The link between resistance and breakthrough infection is an association within the audit.