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The uva ursi plant is a low-lying evergreen bush whose berries are a favorite of bears, hence the name "bearberry." However, it is the leaves that are used medicinally.
Uva ursi has a long history of use for treating urinary conditions in both America and Europe. Up until the development of sulfa antibiotics, its principal active component, arbutin, was frequently prescribed as a urinary antiseptic.
Although we dont know for sure how uva ursi works, it appears that the arbutin contained in uva ursi leaves is broken down in the intestine to another chemical, hydroquinone. This chemical is altered a bit by the liver and then sent to the kidneys for excretion.1 In the bladder, it acts as an antiseptic.
Uva ursi appears to be most effective in an alkaline urine, so taking vitamin C with uva ursi probably hampers its work.2,3
-------------------------------------------------------------------------------- What Is Uva Ursi Used for Today? The European Scientific Cooperative on Phytotherapy recommends uva ursi for "uncomplicated infections of the urinary tract such as cystitis when antibiotic treatment is not considered essential."4 This herb is most useful for women who can tell when they are just starting to develop a bladder infection and can start treatment early. Once you have a severe bladder infection, uva ursi probably won't work very well. Warning: The herb is definitely not appropriate for kidney infections. If you develop symptoms such as high fever, chills, nausea, vomiting, diarrhea, or severe back pain, get medical assistance immediately. Furthermore, because hydroquinone can be toxic (discussed under Safety Issues), it isn't a good idea to take uva ursi for a long period of time. -------------------------------------------------------------------------------- What Is the Scientific Evidence for Uva Ursi? The research foundation for uva ursi is surprisingly weak considering the popularity of this herb.5 Treatment No double-blind studies have evaluated the clinical effectiveness of uva ursi. However, two studies have evaluated the antibacterial power of the urine of people given uva ursi, and have found activity against most major bacteria that infect the urinary tract.6,7 This doesn't prove much, however. Prevention One double-blind study followed 57 women for 1 year. Half were given a standardized dose of uva ursi (in combination with dandelion leaf, intended to promote urine flow), while the others received placebo. Over the course of the study, none of the women taking the combination developed a bladder infection, while five of the untreated women did.8 However, most experts do not believe that continuous treatment with uva ursi is a good idea (see Safety Issues). -------------------------------------------------------------------------------- Dosage The dosage of uva ursi should be adjusted to provide 400 to 800 mg of arbutin daily.9,10,11 This dosage should not be exceeded, and if the herb is not successful within a week you should definitely seek medical attention. No more than 2 weeks of treatment with uva ursi is recommended, and it should not be used more than five times a year. Uva ursi should be taken with meals to minimize gastrointestinal upset. Because uva ursi is most effective in alkaline urine, it should not be combined with vitamin C or cranberry juice. You might try taking it along with calcium citrate to alkalinize the urine instead. Uva ursi is also frequently sold in combination with other herbs traditionally thought to be helpful for bladder infections, including dandelion, cleavers, juniper berry, buchu, and parsley. -------------------------------------------------------------------------------- Safety Issues Unfortunately, hydroquinone is a liver toxin, carcinogen, and irritant.12–15 For this reason, uva ursi is not recommended for young children, pregnant or nursing women, or those with severe liver or kidney disease. However, significant problems are rare among individuals using prepared uva ursi products in appropriate doses for a short period of time. Gastrointestinal distress (ranging from mild nausea and diarrhea to vomiting) can occur, especially with prolonged use.16 -------------------------------------------------------------------------------- Interactions You Should Know About If you are taking drugs or supplements that acidify the urine, such as cranberry juice, uva ursi may not work very well. References 1. Frohne VD. The urinary disinfectant effect of extract from leaves uva ursi [in German; English abstract]. Planta Med. 1970;18:1–25. 2. Tyler V. Herbs of Choice. New York, NY: Pharmaceutical Products Press; 1994:79. 3. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients used in Food, Drugs, and Cosmetics. 2nd ed. New York, NY: Wiley; 1996:505. 4. European Scientific Cooperative on Phytotherapy. Uvae ursi Folium. Exeter, UK: ESCOP, 1997. Monographs on the Medicinal Uses of Plant Drugs, Fascicule 5. 5. Schulz V, Hansel R, Tyler VE. Rational Phytotherapy: A Physician’s Guide to Herbal Medicine. 3rd ed. Berlin, Germany: Springer-Verlag; 1998:223. 6. Frohne VD. The urinary disinfectant effect of extract from leaves uva ursi [in German; English abstract]. Planta Med. 1970;18:1–25. 7. Kedzia B, Wrocinski T, Mrugasiewicz K, et al. Antibacterial action of urine containing arbutine metabolism [in Polish; English summary]. Med Dosw Mikrobiol. 1975;27:305–314. 8. Larsson B, Jonasson A, Fianu S. Prophylactic effect of UVA-E in women with recurrent cystitis: a preliminary report. Curr Ther Res . 1993;53:441–443. 9. European Scientific Cooperative on Phytotherapy. Uvae ursi Folium. Exeter, UK: ESCOP, 1997. Monographs on the Medicinal Uses of Plant Drugs, Fascicule 5. 10. Tyler V. Herbs of Choice. New York, NY: Pharmaceutical Products Press; 1994:79. 11. Schulz V, Hansel R, Tyler VE. Rational Phytotherapy: A Physician’s Guide to Herbal Medicine. 3rd ed. Berlin, Germany: Springer-Verlag; 1998:224. 12. Nowak AK, Shilkin KB, Jeffrey GP. Darkroom hepatitis after exposure to hydroquinone [letter]. Lancet. 1995;345:1187. 13. U.S. Environmental Protection Agency. Extremely Hazardous Substances. Superfund Chemical Profiles. Park Ridge, NJ: Noyes Data Corporation; 1988:1906–1907. 14. Lewis RJ Sr. Sax’s Dangerous Properties of Industrial Materials. 8th ed. New York, NY: Van Nostrand Reinhold; 1989:1906–1907. 15. Schulz V, Hansel R, Tyler VE. Rational Phytotherapy: A Physician’s Guide to Herbal Medicine. 3rd ed. Berlin, Germany: Springer-Verlag; 1998:223. 16. European Scientific Cooperative on Phytotherapy. Uvae ursi Folium. Exeter, UK: ESCOP, 1997. Monographs on the Medicinal Uses of Plant Drugs, Fascicule 5. |
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