Case in which 2 cupfuls of an infusion made of 2 handfuls of coffee produced intense general tremors, lasting, in spite of bromide treatment, twelve hours after all other symptoms had disappeared.
Cohn (Therap. Monats., Mar., '89).
Therapeuties.—Coffee infusion is a most valuable stimulant for cases of nar cotic poisoning, opium, belladonna, chlo ral, etc. While it may prove effective when administered by the mouth, it acts with far greater rapidity when adminis tered by rectal injection. It may be given ad libitum in such cases, and its effects will appear sooner in proportion as the infusion is strong.
The rapidity of absorption is enhanced if the temperature of the infusion ap proximates that of the intestine (100° F.), since cold or heat produce moment ary shock from which the intestinal walls must recover before the absorption can begin. (Sajous.) In the collapse of anmsthesia, the toxic effects of venomous stings and bites, it is an invaluable adjuvant when employed by rectal injection. It sustains all the vital functions while the poison is exert ing its effects, and carries the patient through the ordeal.
Caffeine.
Caffeine should be obtained from the dried seeds of coffee, but the caf feine of the drug-stores is really theine, since it is cheaper to manufacture the alkaloid from damag-ed tea than coffee.
It occurs as long, fleecy crystals, silky in appearance, having no particular odor and bitter to the taste. It is soluble in SO parts of water and fixed proportions of ether, chloroform, and very soluble in boiling water. Caffeine is closely allied to theobromine, found in cacao, coca, and other plants.
Administration and Dose. — Citrated caffeine is frequently employed, owing to its greater solubility; but, Tanret hav ing shown that the addition of equal proportions of the benzoate or salicylate of sodium caused a marked increase of solubility, this mode of prescribing the drug is now often used.
A pleasant preparation is the efferves cent citrated caffeine (U. S. P.), made by "triturating together 10 parts each of caffeine and citric acid, 330 of sodium bicarbonate, 300 of tartaric acid, and 350 of sugar, making the powder into a paste with enough alcohol to make 1000 parts, passing the paste through a No. sieve, drying it, and reducing it to a coarse powder. It must be kept in well-stop pered bottles." The dose is from 1 to 3
drachms.
Physiological Action.—Cohnstein has formulated the following conclusions, which agree with those of most observers: 1. In small doses caffeine produces an increase of the arterial pressure, while larger amounts prevent this increase. 2. The influence upon the blood-pressure is the result of the changed condition of irritability of the vasomotor centre, caused by the caffeine. 3. Caffeine has a direct action on the heart, showing itself in the pulse-frequency and wave height, first as an irritation and then as a paralysis. 4. The heart-muscle is af fected by caffeine in precisely the same manner as the skeletal muscle.
As to the effects of caffeine on blood pressure, Gaetano Vinci found that in all cases there was a rise of ure, whether the drug was administered by the mouth, intravenously, or hypo dermically, with a consequent fall of pressure only in rabbits. In dogs and rabbits subjected to repeated tings, there was a constant rise to the normal, and often far above. In dogs suffering from inanition there was a stant elevation of blood-pressure propor tionate to the weakness of the animal, except in cases where the lowering of vital forces bad gone so far as to affect the heart-muscle.
Schneider found that after therapeutic doses caffeine could not be detected in the urine of cats or men, but that after comparatively-large doses it was readily obtained. Contrary to the opinion of Maly and Andreasch, he thought that the greater part of the drug was destroyed in the body. The discrepancy in the results of these various investigators may have been due, according to C. R. Mar shall, to difference's in the dose adminis tered, the animal used, or the methods of estimation of the alkaloid employed.
Caffeine acts chiefly as a stimulant to the nervous system. In this manner it affects the action of the heart, causing the beats to become stronger, and in sonic cases more rhythmical; but, un like digitalis and stroplianthus, it has no specific action on the inhibitory nerves of that organ. Its action on the vasomotor centres is marked, causing contraction of the vessels and increased tension in the same, the blood-pressure rising. Pawinski (Zeitsch. f. klin. Med., B. 23, 5, (I, '94).