This section is from the book "Materia Medica And Therapeutics: An Introduction to the National Treatment of Disease", by John Mitchell Bruce. Also available from Amazon: The pharmacology and therapeutics of the materia medica.
Pilocarpus. .217 of Pilocarpus pennatifolius. Jaborandi. Imported from Brazil .
Characters. - Leaves dull green, large, pinnate, with 3 to 5 pairs of leaflets and a terminal one. Leaflets coriaceous,
4 to 6 inches long, oblong, lanceolate, emarginate, smooth or only slightly tomentose, and full of pellucid dots.
Impurities. - Leaves of species of piper; not pinnate.
Composition. - Jaborandi contains pilocarpin. a liquid colourless alkaloid, to which its chief effects are due. It is said to contain a second (isomeric) alkaloid, jaborin, closely resembling atropia in its action, and therefore antagonistic to pilocarpin.
Dose. - 5 to 60 gr.
Non-officinal Preparations. Extract. Dose, 2 to10 gr. Fluid Extract. 1 in 1; Dose, 10 to 60 min. Infusion, 1 in 20; Dose. 1 to 2 fl.oz. And Tincture, 1 in 2; Dose, 5 to 20 min. Also Hvdrochlorate and Nitrate of Pilocarpin; Dose of either, 1/20 to 1/2 gr. by the mouth, 1/10 to 1/3 gr. hypodermically. The last is most used.
Externally. - Jaborandi applied to the conjunctiva causes contraction of the pupil, tension of the apparatus of accommodation and disturbance of vision. The effect commences in ten minutes, and lasts from 1 1/2 to 24 hours before finally disappearing. It is used in some cases of inflammation of the eye, such as iritis; in certain forms of blindness; and in paralysis of the muscles. (See Physoatigma, page 230.)
Internally, in full doses, it is liable to cause nausea and vomiting.
Pilocarpin enters the blood rapidly and passes thence into the tissues.
The striking effects of jaborandi consist in profuse salivation, perspiration, disturbances of vision, and circulatory depression, which last for hours, and leave a sense of drowsiness and debility behind them. Salivation is due to stimulation of the terminal ends of the chorda tympani in the glands, as well as of its centre. The flow commences in about five minutes after a moderate dose, and lasts several hours. It increases with the dose. It is completely prevented or arrested by atropia.
Perspiration is referable to stimulation both of the sudoriparous nerves and the sweat centres. It follows quickly on the appearance of the salivation; is accompanied by flushing of the skin, and sometimes rigor; progresses from the head downwards; may be so profuse as to soak the bedclothes; and lasts several hours. The body weight necessarily falls, metabolism is stimulated, and a large quantity of urea is said to be excreted by the skin. Atropia arrests this diaphoresis. The milk is doubtfully increased. The hair grows more actively under a course of jaborandi. Bronchial and nasal secretions flow more freely; even the tears, cerumen, and alimentary secretions are somewhat increased; but not the bile. The amount of urine is moderately raised by small doses. The menses are not affected. The eye is affected specifically, as it is locally. Respiration is not modified directly by pilocarpin. At first the heart and pulse are accelerated, but they are afterwards slowed and weakened; the blood pressure falls temporarily, then rises, and finally falls. Part of these effects are due to the action of the drug on the vagus in the heart, and can be arrested by atropia; part seem referable to the ganglia. The temperature rises before, and falls during, the sweating.
Pilocarpin has been tried in every kind of disease, but is now chiefly given as being a powerful and rapid diaphoretic. In renal dropsy, especially with uraemia, it may be of much service, eliminating a quantity of urea; also in effusions into the pleura and peritoneum; rarely in cardiac dropsy, since in this and every class of case it cannot be safely used if the heart be already weak. It has also been given in syphilis, and in a variety of uterine conditions, with various results. Bronchial catarrh, asthma, and pertussis are all relieved by the flux which it establishes. Small doses relieve the thirst of chronic Bright's disease. In certain dry skin diseases, and certainly in alopecia (baldness), it may answer well. Very conflicting reports have been published of its value in diphtheria, where it is said to loosen or detach the false membrane.