The GT RACING is a study comparing the efficacy of HA-CS bladder installations with prophylactic antibiotics in the prevention of recurrent urinary tract infections (rUTI).

The main objective of the study is to compare efficacy between hyaluronic acid - chondroitin sulphate (HA-CS) treatment and gold standard treatment (AB prophylaxis). Study is set-up as non-inferiority, parallel group cross-over RCT, with a 1:1 randomization.

Study population: Female (>18rs) with at least 3 symptomatic urinary tract infections (UTI's) in the previous year with no adequate curable therapeutic options.

Intervention: 50ml of sterile Ialuril (HA 1.6% CS 2%) weekly for 6 weeks, followed by monthly maintenance therapy for 6 months.

Control : oral nitrofurantoin 100mg daily (1dd100mg or 2dd50mg) for 6 months. In case of resistance/intolerance/allergy for nitrofurantoin alternatively trimethoprim 100mg daily will be given.

All patients recieve both treatments (ialuril and nitrofurantoin) consecutively, for 6 months each. The order of the therapies is determined by randomisation. Between therapies there is a 4 weeks 'wash-out' period. A total of 100 patients will be included.

During the study patients will fill-out questionnaires regarding symptoms, quality of life and use of healthcare. Furthermore urine will be collected at set timepoints.

Main study parameters/endpoints: The main study parameter is the number of UTI per patient-year. Secondary parameters are time to rUTI (wks.), outcome on the global responce assessment (GRA) scale, pattern of antibiotic resistance, outcome on the patient reported outcome questionnaire, cost effectiveness and Quality-of-life.

Inclusion Criteria:

1. Adult female patients (>18 years) who had at least 3 symptomatic UTI's in the previous year with no adequate curable therapeutic options (e.g. bladder stones)
2. At least one UTI's must be confirmed with a positive culture and antibiogram, further UTI's must be confirmed with a urine sediment with positive nitrite or a positive culture.

Exclusion Criteria:

1. Male
2. < 18 years
3. Pregnant
4. Already on GAG therapy
5. Already on prophylactic antibiotics
6. Started or stopped cranberry/d-mannose therapy or vaginal estrogenic creme in the last two months
7. Had Gentamicin or other antibiotic instillations in the previous 2 months
8. Allergic to >3 regular used antibiotics in Dutch guidelines (ed. Nitrofurantoin, trimethoprim, Fosfomycin)
9. A urinary fistula
10. Urinary stones
11. Urogenital cancer
12. Bladder Pain Syndrome - Interstitial Cystitis
13. Chronic pelvic pain
14. Had a STD untreated or treated in the previous 2 months
15. A urinary diversion
16. An Indwelling catheter
17. A suprapubic catheter
18. Performing >1/day self-catheterization
19. A residue after voiding (PVR) of >200ml
20. Unable (also legal) to give informed consent
21. Recurrent urosepsis
22. Multiresistant bacteria in previous urine cultures
23. Contra-indications and interactions for Nitrofurantoin: severe kidney disfunction (GFR < 30), lung- or liver problems or neuropathy after previous use of nitrofurantoin, acute porphyria, known G6PD deficiency, use of magnesium trisilicate.
24. Contra-indications and interactions for trimethoprim: severe kidney or liver dysfunction, blood count abnormality, use of vitamin K antagonists, use of folic acid antagonists, use of ace inhibitors
25. Severe lung/respiratory disfunction (reduced lung capacity, lung cancer, fibrosis, COPD)
26. Does not tolerate catheterization

only anonymous patient data will be shared