Also Known As:
Bearberry, Beargrape, Arctostaphylos uva-ursi.
Family: Ericacea.
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.
Safety:
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
Effectiveness:
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
Adverse Reactions:
Orally, uva ursi may cause nausea, vomiting, gastrointestinal
discomfort, and a greenish-brown discoloration of the
urine.20,15
Interactions with Herbs & Supplements:
None known.
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:
None known.
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
Dosage/Administration:
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.