Does cranberry extract reduce antibiotic use for symptoms of acute uncomplicated urinary tract infections (CUTI)? Protocol for a feasibility study

BACKGROUND: Consultations in primary care for symptoms of urinary tract infections (UTIs) are common and patients are frequently treated with antibiotics. Given increasing antimicrobial resistance, there has been interest in non-antibiotic treatment options for common infections. One such option is the use of cranberry extract to treat symptoms attributable to UTIs. METHODS: A target of 45 women consulting in primary care, with symptoms suggestive of an uncomplicated UTI for whom the practitioner would normally prescribe antibiotics, will be randomised to receive one of three treatment approaches: (1) immediate prescription for antibiotics; (2) immediate prescription for antibiotics plus a 7-day course of cranberry capsules and (3) cranberry capsules plus a delayed prescription for antibiotics to be used in case their symptoms do not get better, or get worse. Follow-up will be by daily rating of symptoms and recording of treatments used for 2 weeks in an online symptom diary. Interviews will be conducted with around 10–15 study participants, as well as with around 10–15 women who have experienced a UTI but have not been approached to take part in the study. Both groups will be asked about their experience of having a UTI, their thoughts on non-antibiotic treatments for UTIs and their thoughts on, or experience of, the feasibility trial. The primary objective is to assess the feasibility of undertaking a full trial in primary care of the effectiveness of cranberry extract to reduce antibiotic use for symptoms of acute uncomplicated UTI. The secondary objective is to conduct a preliminary assessment of the extent to which cranberry might reduce antibiotic use and symptom burden. DISCUSSION: This feasibility study with embedded interviews will inform the planning and sample size calculation of an adequately powered trial to definitively determine whether cranberry helps to alleviate the symptoms of acute uncomplicated UTIs in women and whether it can safely reduce antibiotic use. TRIAL REGISTRATION: ISRCTN registry, ID: 10399299. Registered on 24 January 2019.