Cranberry
Cranberry products are dietary preparations sometimes used in an attempt to reduce the recurrence of urinary tract infections.
ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.
Clinical monograph
How it works
Cranberry contains proanthocyanidins that are proposed to interfere with adhesion of certain bacteria, such as Escherichia coli, to the urinary tract epithelium.
Prescribing in practice
- Cranberry is not a treatment for an established urinary tract infection and should not replace antibiotics where these are indicated.
- It may potentiate the effect of warfarin, so caution and closer anticoagulation review are advised in patients taking warfarin.
- Evidence of benefit is limited and inconsistent, and it should not delay appropriate medical assessment of urinary symptoms.
Monitoring
No specific laboratory monitoring is required, but review anticoagulation control in patients taking warfarin.
Counselling the patient
- Cranberry does not treat an active infection; seek medical advice if you have urinary symptoms.
- Tell your clinician you are taking cranberry if you are on warfarin.
Evidence & guidelines
Evidence for cranberry in preventing recurrent urinary tract infection is limited and inconsistent across systematic reviews.
Reference: Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).
Related
Curated clinical cross-links plus same-class fallbacks.