Uva Ursi. - Synonym. - Bearberry. The leaves of Arctostaphylos Uva Ursi (Linne) Sprengel (nat. ord. Ericaceae).

Habitat

Northern Hemisphere, in dry and sandy or rocky places; in the United States, south to Pennsylvania, New Mexico, and California.

Characters

Very short-stalked, obovate or oblong-spatulate, coriaceous, from 15 to 20 mm. long, and 5 to 8 mm. broad, obtuse, slightly revolute on the margin, upper surface with depressed veins; lower surface distinctly reticulate; odor faint, hay-like; taste strongly astringent, and somewhat bitter. Resembling Uva Ursi. - Senna (see p. 493) and Buchu {see p. 570.)

Composition

The chief constituents are - (1) Arbutin, C12H16O7, a bitter, crystalline glucoside yielding glucose, hydroquinone and methyl-hydro-quinone. (2) Ericolin C10H16O, a bitter, crystalline glucoside. (3) Ursone, a tasteless neutral body. (4) Tannic Acid, 6 to 7 per cent. (5) Gallic Acid.

Incompatibles. - Iron, lead and silver salts, alkaloids, and gelatin.

Dose, 1/4 to 1 dr.; 1. to 4. gm.

Preparations

1. Extractum Uvae Ursi. - Extract of Uva Ursi. By maceration and percolation with Alcohol and Water, and evaporation. Dose, 5 to 15 gr.; .30 to 1.00 gm.

2. Extractum Uvae Ursi Fluidum. - Fluid Extract of Uva Ursi. By maceration and percolation with Glycerin, Alcohol and Water, and evaporation.

Dose, 1/4 to 1 fl. dr.; 1. to 4. c.c

Action Of Uva Ursi

Uva ursi is a well-marked diuretic, and is astringent and disinfectant to the urinary mucous membrane. Its disinfectant action is probably due to the decomposition of the arbutin into glucose and hydroquinone, for after uva ursi is given this substance is found in the urine, and it is a very energetic antiseptic. This decomposition must take place in the kidneys, for hydroquinone is a powerful poison. Against this being the reason of the disinfectant action of the uva ursi, it is urged that giving arbutin does not disinfect the urine; but others deny this, and the probability is that the first-mentioned view is correct. Arbutin itself is a diuretic. The urine may be a pale greenish to dark greenish-brown color. Hydroquinone is also found in the urine in carbolic acid poisoning {see p. 332). The fluid extract is an excellent remedy for ardor urinae of acute gonorrhoea. The astringent action of uva ursi on the urinary tract is usually ascribed to the gallic and tannic acids, but as these are not remote astringents this is most likely wrong.

Therapeutics Of Uva Ursi

Uva ursi is given to disinfect the urine in the same class of cases as buchu - that is to say, in pyelitis, cystitis and gonorrhoea.