COCA AND COCAINE.
Erythroxylon coca is a small tree thaP grows wild in Peru, Bolivia, Brazil, and'' Ecuador. The leaf, which contains the' active principles, is the part used in medicine. Three alkaloids, hygrine, ecgonine, and cocaine have been isolateet from the cocoa-leaves. Cocaine, the on1:14 one that has been found useful in medi;- eine, occurs in colorless, transparent crystals, which are soluble in alcohol, ether, chloroform, and fats. Cocaine forms salts with the acids, the hydro chlorate being official and the one usually used. The salts cannot be used for ing ointments, as they are soluble in fats.
Preparation and Dose.—Coca (leaves), 1/, to 1 drachm.
Extractum cocm fluidum, 1/2 to 2 drachms.
Cocaine carbolate, 1/„ to 1/. grain. Cocaine hydrocbloras, 1/4 to 2 grains.
Coca is best administered either as a tonic or coca, such as vin 3Iariani, or in the form of the fluid extract. When ad ministering coca or cocaine the pos sibility of intolerance on the part of the patient should be borne in mind and the danger of inducing the cocaine habit re membered. Solutions of cocaine hydro chlorate are bitter, and provoke transient insensibility of the tongue. Aqueous solutions do not keep well, but decom pose in a short time and lose their effi ciency.
Series of experiments indicating (1) that chloral-hydrate is a decided antag onist of cocaine, being able to counter act the action of doubly-lethal doses given to a dog; (2) other hypnotics, such as paraldehyde, are likewise an tagonistic to cocaine; (3) the antag onism is complete, influencing all the important organic functions; (4) it is a one-sided antagonism, for cocaine does not counteract poisoning by the hyp notics; (5) the antagonism is Et mechan ical one, similar to the antagonisrn be tween the hypnoties and strychnine. Carlo GiofTredi (Giornale Inter. delle Scienze Med., Aug. 31, 1900).
Physiological Action.—When taken internally, coca and its alkaloid produce a sensation of exhilaration and pleasure similar to that produced by a large dose of caffeine. There is a marked tendency to wakefulness, a feeling of increased mental and muscular strength and vigor, and an absence of hunger. The brain is stimulated, but the sensory nerves are not generally affected, and, if at all, the effect is very feeble and is due to an influence on the spinal cord (Mosso). When applied locally to the sensory nerves cocaine paralyzes them. This
also happens if the internal dose be very •large. The effect upon the muscles when taken internally is direct stimulation, most marked after fatigue.
Maurel, of Toulouse, has shown that under the influence of cocaine the leuco cytes undergo changes; they become spherical and rigid, increase in size, and no longer adhere to the vessel-walls. On the other hand, the capillaries contract, and thrombosis and embolism—particu larly pulmonary embolism—may be pro duced.
Upon the heart and circulation co caine in moderate amounts acts as a stimulant, the heart-beats being in creased in number and force; but marked effects only follow a poisonous dose. Cocaine is a respiratory stimulant, large doses increasing the number of respira tions; in poisonous doses it kills by fail ure of respiration associated with exhaus tion from the accompanying convulsions (llare). Cocaine increases body-heat to a marked degree if given in overdose, this rise being due to increase of heat production (Reichert). When applied locally to mucous membranes, cocaine produces an anfesthetic effect, accom panied with a blanching of the mem brane, followed by a marked congestion. When injected beneath the skin cocabae produces a local-ansthetic effect. Ap plied externally to the skin it produces little effect.
The rise of temperature caused by cocaine is due to an increase of heat production, and the latter depends upon two actions: one, of the cortex., causing motor excitement, and the other, upon the caudate thermogenic centre, by which heat is produced independently of motor activity. Cocaine possesses very little power as a thermogenic in ani mals lig,htly curarized. because of both the motor quietude and the depression of some other portion of the thermo genie apparatus. It is absolutely with out thermogenic power in animals in which the pathways of thermogenic and cortico-spinal motor fibres have been cut, as after section of the spinal cord at its junction with the bulb and of crura cerebri. Cocaine Is effective a.s a thermogenic when only a small portion of the caudate centre is left intact with the parts below. Cocaine and morphine are direct antagonists in their actions upon the caudate and cortical centres which are directly or indirectly involved in the changes of temperature and heat production. E. T. Reichert (Phila. Med. Jour., Aug. 2, 1002).