Dr Dilis Clares Materia Medica
Introduction to the Dispensing of Dr Clare’s Blended Herbs
(Last edited: Tuesday, 31 March 2015, 10:05 PM)
Also Known As:
Bearberry, Beargrape, Arctostaphylos uva-ursi.
People Use This For:
Orally, uva ursi is used for urinary tract infections, inflammatory conditions of the urinary tract, cystitis, urethritis, diuresis, constipation, stones in the urinary tract, painful urination, acidic urine, kidney infection, benign prostatic hyperplasia.
No concerns regarding safety when used orally and appropriately, short-term.
Preliminary clinical research suggests that uva ursi is likely to be safe when used short-term.13,14
Possibly unsafe when used orally long-term because of the hydroquinone constituent of uva ursi.
Pregnancy and Lactation: Refer to a Medical Herbalist
Not enough scientific information gather to offer a comment.
Urinary tract infections (UTIs). Preliminary evidence suggests that taking a combination product containing both uva ursi and dandelion orally seems to significantly reduce the recurrence rate of UTIs in women.14 However, since it isn't clear if this kind of extended use is safe, advise patients not to use uva ursi for long-term prevention of UTIs.
Mechanism of Action:
Arbutin hydrolyses to hydroquinone which is an effective urinary antiseptic.R9
It is also cytotoxic and mutagenic and so excessive doses should be avoided.R10
Arbutin is absorbed from the gastrointestinal tract unchanged and is hydrolyzed to hydroquinone in alkaline urine. There it can exert antiseptic and astringent effects.15,16,17 For this reason, urinary acidifying agents may decrease the effectiveness of uva ursi, and urinary alkalinizing agents may increase its effectiveness.18
Hydroquinone, contained in uva ursi, is a tyrosine kinase inhibitor which inhibits melanin production. Melanin is present in various ocular layers . Changes in melanin metabolism may result in retinal thinning19 (This was one case following 3 years use). Hydroquinone is cytotoxic in lab studies.15 In rats, uva ursi has anti-inflammatory activity against experimentally-induced inflammation.15
Orally, uva ursi may cause nausea, vomiting, gastrointestinal discomfort, and a greenish-brown discoloration of the urine.20,15
Interactions with Herbs & Supplements:
Interactions with Drugs:
Lithium: Due to diuretic properties which theoretically may affect the dose of lithium required. Refer to a Medical Herbalist.
Interactions with Foods:
Interactions with Lab Tests:
Colorimetric Urine Tests: Theoretically, uva ursi can interfere with colorimetric urine tests and can turn urine greenish-brown.15
Interactions with Diseases or Conditions:
Retinal Thinning: Theoretically, uva ursi might worsen retinal thinning in patients with this condition. Long-term use of uva ursi should be avoided in these patients.19
Oral: The typical dose of dried herb is 1.5-4 grams daily.15 It's also commonly used as a tea. The tea is prepared by steeping 3 grams of the dried leaf in 150 mL cold water for 12-24 hours and then straining. One cup of tea is usually taken up to 4 times daily.20,17,21 Uva ursi leaf teas should be prepared with cold water to minimize the tannin content.21 The hydroquinone derivative, calculated as water-free arbutin, is commonly dosed as 100-210 mg up to 4 times daily.20,17,21 The
fluid extract (1:1 in 25% alcohol) is given 1.5-4 mL three times daily.15 Medical consultation is needed for urinary tract symptoms persisting longer than 48 hours.15 Uva ursi should not be used longer than one week without monitoring due to its potential risks.17 Limit its use to less than five times per year.17
Spedific References: UVA URSI
13. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
14. Larsson B, Jonasson A, Fianu S. Prophylactic effect of UVA-E in women with recurrent cystitis: a preliminary report. Curr Ther Res 1993;53:441-3.
15. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
16. Foster S, Tyler VE. Tyler's Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies. 3rd ed., Binghamton, NY: Haworth Herbal Press, 1993.
17. Schulz V, Hansel R, Tyler VE. Rational Phytotherapy: A Physician's Guide to Herbal Medicine. Terry C. Telger, transl. 3rd ed. Berlin, GER: Springer, 1998.
18. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
19. Wang L, Del Priore LV. Bull's-eye maculopathy secondary to herbal toxicity from uva ursi. Am J Ophthalmol 2004;137:1135-7.
20. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
21. Foster S, Tyler VE. Tyler's Honest Herbal, 4th ed., Binghamton, NY: Haworth Herbal Press, 1999.