<h2>Practice points</h2><ul><li>Cranberry may be useful in preventing the recurrence of urinary tract infections (UTIs) but there is insufficient evidence to suggest benefits during an acute infection</li><li>Using cranberry products twice or more daily may be more effective than single daily dosing</li><li>Solid-dose forms (capsules or tablets) are likely to have better compliance and are usually more cost-effective than juices</li></ul><h2>Key indications</h2>UTI Prevention: Some systematic reviews indicate that cranberry-containing products may prevent recurrence of UTIs.1 However, results have been mixed due to heterogeneity in trials.1 A 2017 meta-analysis of 7 randomised controlled trials found that cranberry was effective in reducing the risk of recurrent UTI in healthy women by 23%. Cranberry was more effective in interventions with cranberry as a capsule or tablet.7 In experimental studies type-A proanthocyanidins (PACs) found in cranberry products, appear to dose-dependently inhibit the adhesion of bacteria to uroepithelial cells, impairing colonisation and subsequent infection.3 They may also impair the biofilm that can make some bacteria more resistant to antibiotics (IV)4Children: Cranberry-containing products may prevent recurrence of UTIs in children but again, systematic reviews have produced mixed results.1,2<h2>Key actions5</h2><ul><li>Bacteriostatic</li><li>Antiadhesive</li><li>Antioxidant</li></ul>

<h2>Dosage range</h2><ul><li>In human studies, cranberry preparations containing 36mg PAC/ day appear to be effective in inhibiting bacterial adhesion, however more pronounced effects are seen with 72 mg PAC/ day doses3</li><li>As the half-life of PACs is around 8 hours, using cranberry products more than twice daily may be more effective than once-a-day dosing in reducing the risk of UTI recurrence1</li></ul>

Dosage

<h2>Adverse effects</h2><ul><li>High doses may result in GIT disturbance including diarrhoea5</li></ul>

Adverse Effects

<h2>Cautions/ Contraindications</h2><ul><li>Surveys of pregnant women taking cranberry have not revealed any adverse effects.6 However, benefits for pregnant women have also not been confirmed2 </li><li>The safety or harm of cranberry during lactation is unknown6</li><li>Cranberries contain oxylates and may not be suitable for people at risk of kidney stones5</li></ul>

Cautions

<h2>Key interactions</h2><ul><li>Anti-coagulant and antiplatelet agents: may increase blood levels of the drug. Clinical trials suggest no evidence of increasing drug effect with cranberry juice. Case reports exist. In vitro studies suggest cranberry affects warfarin metabolism (CYP3A4 metaboliser). Unlikely likelihood. Use with caution under supervision of a healthcare professional (HCP)</li><li>CYP3A substrates: may increase or decrease blood levels of drug via inhibition of this enzyme activity. Possible likelihood. Use with caution under supervision of a HCP</li><li>Tacrolimus: may decrease drug effect. Likelihood possible. Avoid concomitant use</li></ul>For more information visit: <a href="https://www.blackmoresinstitute.org/interactions" target="_blank">https://www.blackmoresinstitute.org/interactions</a>

Interactions

1. Wang CH, Fang CC, Chen NC, et al. Cranberry-containing products for prevention of urinary tract infections in susceptible populations: a systematic review and meta-analysis of randomized controlled trials. Archives of internal medicine 2012;172(13):988-96. 2. Jepson RG, Williams G, Craig JC. Cranberries for preventing urinary tract infections. Cochrane database of systematic reviews 2012;10:CD001321.3. Howell AB, Botto H, Combescure C, et al. Dosage effect on uropathogenic Escherichia coli anti-adhesion activity in urine following consumption of cranberry powder standardized for proanthocyanidin content: a multicentric randomized double blind study. BMC Infect Dis 2010;10:94. 4. Ulrey RK, Barksdale SM, Zhou W, et al. Cranberry proanthocyanidins have anti-biofi lm properties against Pseudomonas aeruginosa. BMC complementary and alternative medicine 2014;14:499. 5. Braun L, Cohen M. Cranberry. Herbs &amp; natural supplements: an evidence based guide.[Vol. 2]. 4th ed. Australia: Elsevier; 2015. p.247-55. 6. Dugoua JJ, Seely D, Perri D, et al. Safety and effi cacy of cranberry (vaccinium macrocarpon) during pregnancy and lactation. Can J Clin Pharmacol 2008;15(1):e80-6. 7. Fu Z, Liska D, Talan D, Chung M. (2017). An Updated Meta-Analysis of Cranberry and Recurrent Urinary Tract Infections in Women. FASEB J 2017;31(1 Supplement):lb343.8. Complementary medicine interaction guide 2019. https://www.blackmoresinstitute.org/interactions

Cranberry

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