Uva ursi (arctostaphylos uva-ursi)

What is uva ursi? What is it used for?

Uva ursi is a small, evergreen shrub that grows in colder northern climates, including North America, Europe, Siberia, and the Himalayas. The shrub contains small, thumb-shaped green leaves, pinkish-white flowers, and reddish or pinkish berries. Bears are believed to be especially fond of the berries; hence the plant's two nicknames, "bearberry" and "beargrape." Both the leaves and berries are used in herbal preparations.

The active ingredient in uva ursi is called arbutin, which accounts for up to 10 percent of the plant's weight, and has been shown to kill bacteria in the urine. During urination, arbutin interacts with the mucus membranes of the urinary tract, helping to soothe irritation and reduce inflammation. It also works in conjunction with a substance called hydroquinone in the intestines to aid in the transport of water to the kidneys. Although no human studies have been published on the subject, uva ursi is believed to help treat urinary tract infections.

How much uva ursi should I take?

For urinary conditions, the German Commission E monograph suggests three grams of uva ursi taken in 150 milliliters of water as an infusion three to four times daily. For alcohol-based tinctures, five milliliters TID can be taken. For herbal extracts or capsules (containing 20 percent arbutin), 250-500mg TID can also be taken. However, use of uva ursi should be limited to no more than 14 days consecutively.

What forms of uva ursi are available?

Uva ursi is available in several forms, including powders, tinctures, extracts, capsules, teas, and tablets.

What can happen if I take too much uva ursi? Are there any interactions I should be aware of? What precautions should I take?

Some patients may become nauseous or have difficulty sleeping after taking uva ursi due to its high tannin content. Prolonged use (more than two to three weeks) is not recommended, as it may cause intestinal disorders. In addition, people should not take acidic liquids such as cranberry juice or prune juice, or more than 500mg of vitamin C, while using uva ursi. It should not be used by pregnant or lactating women, or by people with high blood pressure, and it should be used in children only with the guidance of a health care professional.

Uva ursi may react negatively with several types of medications, including atropine, codeine, ephedrine, pseudoephedrine, loop diuretics and thiazide diuretics. Patients taking these and other medications should not take uva ursi, and should consult with a licensed health care provider before considering supplementing with uva ursi or any other herbal remedy or dietary supplement.

References

• Blumenthal M, Goldberg A, Brinckmann J (eds.) Herbal Medicine: Expanded Commission E Monographs. Boston: Integrative Medicine Communications; 2000, pp. 389-393.
• Gruenwald J, Brendler T, Jaenicke C, et al. (eds.) PDR for Herbal Medicines, 2nd ed. Montvale, NJ: Medical Economics Company; 2000, pp.779-782.
• Ottariano SG. Medicinal Herbal Therapy: A Pharmacist's Viewpoint. Portsmouth, NH: Nicolin Fields Publishing, 1999, p. 83.
• Parejo I, Viladomat F, Bastida J, et al. A single extraction step in the quantitative analysis of arbutin in bearberry (arctostaphylos uva-ursi) leaves by high-performance liquid chromatography. Phytochem Anal. 2001;12(5):336-339.
• Rotblatt M, Ziment I. Evidence-Based Herbal Medicine. Philadelphia:Hanley & Belfus, Inc., 2002, pp. 351-354.