This section is from the "A Practical Treatise On Materia Medica And Therapeutics" book, by Roberts Bartholow. Also available from Amazon: A Practical Treatise On Materia Medica And Therapeutics
Jaborandi. The leaflets of Pilocarpus Selloanus Eng-ler (Nat. Ord. Rutaceae, Xanthoxyleae).
Infusion of pilocarpus ( oz ij—Oj). Dose, oz ss — oz ij. (Not official.)
Fluid extract of pilocarpus. Dose, 3 ss — 3 ij.
Tincture of pilocarpus (oz iv—Oj). Dose, 3 ss — 3 ij- (Not official.)
The important constituent is the alkaloid—pilocarpine—which possesses the physiological properties of the drug. It combines with acids to form salts. The salts of pilocarpine crystallize in the oblique system. In 1880 another alkaloid was discovered, and to this the name jaborine was given (Harnack und Meyer). Subsequent researches fully confirmed this (P. Castaing). These alkaloids are closely related in composition: probably identical, but having a different molecular arrangement. By heat, merely by concentration of an acid solution, pilocarpine is converted into jaborine (Hans Meyer); and by washing with absolute alcohol they are separated, when united, as is very often the case in the commercial article. As these two alkaloids differ very greatly in properties, it is not surprising that the observations made with pilocarpine at first were very discrepant. Chemically they differ in that the salts of jaborine do not crystallize, and they dissolve more easily in ether and less easily in water. Physiologically, they differ even more decidedly. Jaborine acts like atropine, to which pilocarpine is a physiological antagonist.
Pilocarpine hydrochlorate. Minute, white crystals, deliquescent, odorless, having a faintly bitter taste and a neutral reaction. Very soluble in water and in alcohol, but almost insoluble in ether or chloroform. Dose, gr.1/12—gr. ss.
The caustic alkalies, the per-salts of iron, and the salts of the metals generally, are chemically incompatible. A remarkable antagonism has been shown to exist between pilocarpine and belladonna (Ringer and Gould).
Aconite, veratrum viride, gelsemium, and remedies which paralyze the vaso-motor nervous system, promote the activity of jaborandi.
The taste of jaborandi is rather hot and pungent. The considerable doses of the crude drug required to produce physiological effects excite nausea and vomiting, especially if taken on an empty stomach. It has been shown, however, in recent experiments, that these results follow the use of the alkaloid; hence it may be concluded that not bulk alone is the cause of the gastric distress, but that it is one of the physiological properties of the drug.
The active principles of jaborandi diffuse readily into the blood. In about ten minutes after the infusion is swallowed, the face, ears, and neck become deeply flushed. Simultaneously perspiration begins on the skin, an abundant flow of saliva takes place, the nasal and bronchial mucus, and the tears, are increased, and watery diarrhoea may occur. It is said that, when the salivary secretion is greatly increased, that of the skin is relatively less so, and vice versa (Féréol), but this is not generally admitted. The quantity of perspiration poured out by the skin is enormous—the sweat runs from the body and soaks the clothes. The quantity of saliva discharged is also very great. Ringer reports that in two of his cases the amount of saliva was respectively twenty-two ounces and twenty-seven ounces. According to Petithau, the sialogogue effect is constant, the diaphoretic action is somewhat less certain, and the diuretic effect uncertain. These conclusions are in accord with the general experience.