Pareirae Radix, B.P. Pareira Root.
Related entry: Cissampelos
Pareira root (Pareira, U.S.P.), or Pareira Brava, is obtained from Chondrodendron tomentosum, Ruiz and Pavon (N.O. Menispermaceae), a climbing plant indigenous to Peru and Brazil. It occurs in more or less tortuous, heavy cylindrical pieces from 2 to 5 centimetres or more in diameter, almost black in colour, and marked with longitudinal furrows and transverse ridges and fissures. The transverse section exhibits a central column composed of ten to twenty wedges of wood, containing large vessels; surrounding the central column are three or four zones, separated from each other by light coloured, wavy lines, and each consisting of sparsely distributed wood bundles separated by wide, dense, wavy medullary rays. The drug has a bitter taste, but no odour. It yields about 4 per cent. of ash and more than 10 per cent. of aqueous extract. Much of the commercial drug is not genuine, the chief substitute being the root of a Brazilian menispermaceous plant closely allied to Chondrodendron; this drug is in straighter, brownish pieces, which are not so heavy; the section is much less waxy and exhibits more numerous, narrower zones, the vessels in which are about half the diameter of those of the genuine; it has also a less bitter taste and yields less aqueous extract. The stems of true pareira are paler in colour, bear lichens, have a more or less warty surface, and exhibit a well-defined pith.
Constituents.—The root contains alkaloidal matter, of which about 10 per cent. consists of beberine, formerly called pelosine; an amorphous alkaloid named chondrodine is also present. The drug is remarkable for the large quantity of free fatty acids (9 per cent.), chiefly stearic acid, which it contains. Other constituents of the root are tannin and abundant starch.
Action and Uses.—Pareira root is employed as a simple bitter, and as a diuretic in catarrhal affections of the genito-urinary system, gonorrhoea, cystitis, and leucorrhoea. It is used principally in the form of liquid extract and decoction.
- Decoctum Pareirae, B.P., 1885.—DECOCTION OF PAREIRA.
- Pareira root, in No. 20 powder, 6.25; distilled water, sufficient to produce 100. Add the powdered root to 120 of the water, boil for fifteen minutes, strain, and make up to the required volume, if necessary, by passing distilled water through the strainer. Decoction of pareira should be strained hot; a preparation different in physical appearance is obtained if the decoction is allowed to cool before straining. It is employed in catarrhal affections of the genito-urinary organs. Dose.—15 to 60 mils (½, to 2 fluid ounces).
- Extractum Pareirae Liquidum, B.P.—LIQUID EXTRACT OF PAREIRA.
- Pareira root, in No. 40 powder, 100.; alcohol, a sufficient quantity; distilled water, boiling, a sufficient quantity. Mix the drug with about 120 of the boiling water, allow to macerate for twenty-four hours, then pack in a percolator and percolate with boiling water till exhausted. Determine the proportion of extractive matter in the percolate, evaporate the latter until it contains one-third its weight of extractive, and add sufficient alcohol to increase the volume of product by one-third, afterwards filtering if necessary. The following modified process has been suggested as yielding a superior preparation to the official liquid extract of pareira:—Mix together 20 of alcohol, 120 of glycerin, and 60 of distilled water; moisten 100 of pareira root, in No. 10 powder, with 40 of the mixture; then pack in a percolator, and percolate with the remainder of the mixture, continuing the percolation with alcohol (20 per cent.) until exhaustion is complete. Reserve the first 75 of percolate, concentrate the remainder to a soft extract, dissolve this in the reserved portion, and add sufficient alcohol (20 per cent.) to make up to the required volume. Liquid extract of pareira usually throws down a heavy deposit, and is difficult to filter. It is used in catarrhal affections of the genito-urinary system, but its value is very doubtful. The extract is best prescribed in mixture form, with infusion of buchu or bearberry. Dose.—2 to 8 mils (1 to 2 fluid drachms).
- Fluidextractum Pareirae, U.S.P.—FLUIDEXTRACT OF PAREIRA.
- Pareira, in No. 40 powder, 100; glycerin, 10; alcohol (95 per cent.) and water, sufficient to produce 100. Average dose.—2 mils (30 minims).