This section is from the book "Materia Medica Pharmacy, Pharmacology And Therapeutics", by W. Hale White. Also available from Amazon: Materia Medica Pharmacy, Pharmacology And Therapeutics..
Northern and Western Brazil.
Subglobular or elliptic cakes, or cylindrical sticks, hard, dark reddish-brown; fracture uneven, somewhat glossy, pale reddish-brown, showing fragments of seeds invested with blackish-brown integuments; odor slight, peculiar, resembling that of chocolate; taste, astringent and bitter.
Dose, 1/4 to 1 dr.; 1. to 4. gm.
By maceration and percolation with Alcohol and water, and evaporation. Dose, 1/4 to 1 fl. dr.; 1. to 4. c.c.
Although there is no reason to believe that guaranine does not produce the same action on the nervous system, heart and kidneys as caffeine, yet it is rarely used except for sick headaches; but in these cases it is sometimes of the greatest service.