A preparation from the seeds of Paullinia sorbilis, a tree. Nat. Ord. Sapindaceae, indigenous in Brazil. It occurs in cylindrical or spherical pieces of about a pound weight each, surface uneven, brown, sometimes black; so hard as to be broken with difficulty, fracture conchoidal, unequal, resinoid; colour reddish brown, resembling chocolate. Sometimes these pieces are reduced to powder and sold in that state. Its efficacy as a medicine appears to depend upon a crystallizable principle named Guaranine, which, if not identical with, is closely allied to theine and caffeine, possessing the following elementary constituents, C8H10N4.

Med. Action and Uses. By the Brazilians Guarana is held in high esteem as a stomachic, febrifuge, and aphrodisiac, and is employed by them in dysentery, diarrhoea, retention of urine, and various other affections. Its qualities have been examined by Martius and Gavrelle,§ who agree in regarding it as a valuable addition to the Materia Medica. According to them, it stimulates, and at the same time soothes the gastric system of nerves, and reduces the excited sensibility of the caeliac plexus, thereby diminishing febrile action and strengthening the stomach and intestines, particularly restraining any excessive mucous discharges. At the same time it was found to increase the action of the heart and arteries, and to promote diaphoresis. The dose in powder is gr. lx. three or four times a day. It may be given mixed with water and sugar, or with syrup and mucilage, conjoined with an aromatic. It may also be given in the form of Extract obtained by treating Guarana with Alcohol and evaporating to a pilular consistence.

* Dict. Pract. Med., vol. ii. p. 656.

Ibid., vol. ii. p. 49.

Buchner, Repert. de Pharm., xxxi. p. 370, 1820

§ Sur nne nouvelle Substance Mede-cinale, &c, Paris, 1840.

It is contra-indicated in plethoric or loaded conditions of the abdominal Viscera, and where there exists determination of blood to the head.

1340. Therapeutic Uses

From what has been stated above, Guarana is indicated as a valuable remedy in Fevers, in reduced states of the Vital Power resulting from exposure, cold, &c, Depression of Spirits, and other allied states; also in Colic, Flatulence, Anorexia, Nervous Hemicrania, Excellent effects are said to have resulted from its use in Diarrha and Chronic Dysentery. In cases where Irritation of the Urethra or Bladder succeed venereal or attend organic disease, it is said to exert the most salutary effect in soothing the irritability of the mucous membrane, and relieving the nervous depression which so often attends these affections. It is said to increase the venereal appetite, but to diminish the fecundating power. (Ritchie.)*