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Bearberry Herb - Dosage and Useful Properties
Taxonomic class
Ericaceae
Common Trade Names
Multi-ingredient preparations: Arctuvan, Solvefort, Uroflux, Uvalyst Common forms
Available as drops, tablets, and tea.
Source
The crude drug is obtained from the dry leaves (not berries) of the low, trailing evergreen shrub Arctostaphylos uvaursi (also Arctostaphylos coactylis and Arctostaphylos adenotricha).
Chemical Components
Leaves contain hydroquinone derivatives (mainly arbutin), hydroquinone monoglucoside, and small amounts of methylarbutin. Other compounds include arbutin gallic acid ester, gallotannin, iridoid glycoside monotropein, paracoumaric flavonoids, piceoside, phenol carboxylic acids (mainly gallic), syringic acids, and triterpenes.
Actions
Bearberry contains 5% to 15% arbutin, which hydrolyzes when ingested and releases hydroquinone . Hydroquinone is the principal antiseptic and astringent constituent of the plant . Isoquercetin (a flavonoid pigment) and ursolic acid (a triterpene derivative) contribute to the diuretic action of the extract. Evidence in rats suggests that this effect is minimal.
One study in mice indicated that bearberry may counter the symptoms of diabetes, particularly weight loss, without affecting glycemic control . A Japanese study reports that bearberry increases the inhibitory effect of dexamethasone, indomethacin, and prednisolone in inflammatory and allergic responses. Antityrosinase activity has been described with some constituents of bearberry .
Reported Uses
Bearberry is claimed to be modestly effective as a diuretic and urinary tract antiseptic. It has also been used as a diuretic in veterinary medicine.
Dosage
Doses of 1 to 10 g P.O. daily have been suggested. Doses as high as 20 g have been reported with no adverse effects, but CNS toxicity may appear in some patients from as little as 1 g .
Adverse Reactions
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GI: nausea, vomiting.
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GU: green-colored urine.
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Skin: cyanosis.
Interactions
- Diuretics: Increased electrolyle loss. Avoid administration with bearberry.
Urinaryacidifiers (ascorbic acid, methenamine): Inactivation of bearberry in urine. Avoid administration with bearberry.
Contraindications And Precautions
Avoid using bearberry in pregnant or breast-feeding patients; effects are unknown. Use cautiously in patients taking diuretics; bearberry may promote electrolyte disturbances.
Special Considerations
Alert laboratory technicians conducting urinalyses that the patient's urine may be green because of the effects of bearberry.
Advise the patient that traditional diuretics should be considered over the use of bearberry.
Taken in large doses (more than 20 g as a single dose), bearberry may cause CV collapse, seizures, tinnitus, and vomiting.
Caution the patient taking diuretics that concomitant use of bearberry could lead to excessive electrolyte loss and may increase the likelihood of CV collapse, dizziness, muscle cramps, palpitations, and weakness.
Advise the patient that his urine may turn green.
Advise women to avoid using bearberry during pregnancy or when breast-feeding.
Points of Interest
Urine must have all alkaline pH before bearberry can act as a urinary tract antiseptic.
Commentary
Inadequate data prevent the recommendation of bearberry for any disease state. Further study of this agent and its constituents is needed; bearberry maY have potential as an anti-inflammatory or a weak diuretic.
