Caffeine

“ On the constitution of caffeine see Purin and also E. Fischer (Annalen, 1882, 215, p. 253) .
Caffeine crystallizes in long silky needles, which are slightly soluble in cold water. It becomes anhydrous at 100°C. and melts at 234° to 235°C. It has a faint bitter taste and gives salts with mineral acids. On oxidation with nitric acid caffeine gives cholesterophane (dimethyl parabanic acid) , but if chlorine water be used as the oxidant, then it yields monomethyl urea and dimethyl alloxan (E. Fischer) . ”

“ The volatile oil reduces arterial tension, allows a brisker flow of blood, and so increases the rapidity of the heart's action. It also acts upon the brain, and intellectual faculties in general; keeps one awake, and his mind clear. Caffeine, on the other hand, like digitalis, produces a high arterial tension, and slows the heart beat. It exerts its chief effect upon the spinal cord, to which, like strychnia, it is an excitant. The shaking hand of the inveterate coffee drinker is caused by caffeine. Thus a cup of coffee produces on the drinker a double effect,—of the oil and the alkaloid ”

“ That was what coffee did for me.
I was a caffeine addict.
Earth-norm humans sometimes have the addiction to a slight extent, but I knew that as a Centurian I had it infinitely worse. Caffeine affected my metabolism like a pure alkaloid. ”

“ Such drinks usually purport to be made from the kola nut, which contains caffeine, or to consist of extracts from the plants which yield cocoa and chocolate, when in reality they consist of artificial mixtures to which caffeine has been added. Those using these beverages are stimulated as they would be by tea or coffee and soon acquire the habit which makes them regular customers. Chief harm comes to the children who frequent the soda fountains and to those who, on account of constitutional tendencies, should avoid caffeine in all of its forms. ”

“ Caffeine has been found very useful in hemicrania and various nervous affections. It has also been recommended in dropsy due to heart lesion. Strong, black coffee is very valuable in counteracting poisoning by opium and its derivatives. Coffee will also check vomiting. Strong coffee is apt to develop various nervous troubles, as palpitation of the heart, sleeplessness, indigestion, trembling. According to one authority, it is the aromatic principle of coffee which causes sleeplessness.
[Pg 210]
THE TWO ACORNS. DR. CHARLES MACKAY. ”

“ Coffee is good for you. It’s the caffeine in it. Caffeine, we are here. Caffeine puts a man on her horse and a woman in his grave. ”

“ Now, since 3 drachms of this coca, or three fluid drachms of its fluid extract, gave the same physiological, or perhaps therapeutical, effect as 3 grains of caffeine, and as the 3 drachms contained about 0.45 grain of cocaine, it follows that cocaine is about 6.5 times more effective than caffeine; but it also follows that the coca accessible, and even the very best coca, contains very much less of its alkaloid than those articles which yield caffeine do of that principle. ”

“ Sana laughed, “Well there would be more sense in that. Some people cannot sleep after drinking coffee, while a glass of good beer does much to induce sleep. The caffeine in coffee is a dope, while there is no nourishment in the drink itself. ”

“ One kind puts any and every kind of stuff into stock, and passes it out to his customers, young and old, ignorant or learned, foolish or wise, his only desire being to get a profit. The other kind of druggist refuses to stock some things at all. Kola drinks owe their vogue to the caffeine which they contain. Caffeine is a poison which is cumulative in its effects, and an excess of which has not infrequently caused death. ”

“ The chemist whose genius is responsible for the introduction of caffeine to overcome the depressing effect of some of the other component parts of these preparations has put hundreds of thousands of dollars into the pockets of the manufacturing druggists and has saddled the world with a great and unnecessary weight of physical and mental degeneration. ”

“ In addition to the volatile oil, which is contained in roasted coffee in the proportion of about 1 part in 50,000, coffee contains caffeine, of which there is 3⁄4 to 1 per cent., and an astringent acid, called caffeo-tannic or caffeic acid, which differs from ordinary tannin in that it does not blacken a solution of an iron salt.
The chief adulteration of coffee is Chicory, which is thought by some to improve the coffee. It is generally harmless, though in some people it produces heartburn and diarrhœa. Chicory is prepared from the root of the wild endive. ”

“ When used in considerable quantity, by young or old, it causes a nervous condition both distressing and dangerous, known as "tobacco heart."
Tea and coffee contain a drug, called caffeine, which acts upon the nervous system and which may, on this account, interfere with the proper control of the heart. In some individuals the taking of a very small amount of either tea or coffee is sufficient to cause irregularities in the action of the heart. Tea is considered the milder of the two liquids and the one less liable to injure. ”

“ We believe you would better be on record as discouraging rather than encouraging the growth of . the caffeine habit, especially among young people, who constitute a large part of the soda-water trade. ”

“ Any analytical chemist can analyize coffee and tea, and show that they contain a poisonous drug—caffeine—which belongs to the same class as cocaine, morphine, nicotine and strychnine—alkaloids.
In highly organized people, these poisons have a direct effect upon the heart, liver, stomach and nerves, and set up various indications of approaching sickness. These facts have been known by physicians for many years, but it is difficult to induce people to leave off habits, even when those habits are known to be injurious and shorten the existence of the human body. ”

“ Hot drinks against which the people are warned have been and are understood to include tea and coffee, and the inhibition was preached and published prior to the discovery by chemists that theine, caffeine and kindred alkaloids are of pronounced deleterious and actually poisonous effect. ”

“ Since certain of the effects of coffee drinking have been attributed to this alkaloid, a brief presentment of the pharmacology of caffein will be given as an exposition of the many statements made regarding it. According to the British Pharmaceutical Codex [257] :
Caffein exerts three important actions: (1) on the central nervous system: (2) on muscles, including cardiac: and (3) on the kidney. The action on the central nervous system is mainly on that part of the brain connected with psychical functions. It produces a condition of wakefulness and increased mental activity. ”

“ Coffee and caffein in narcotic poisoning are of value as a means of keeping the patient awake, and of stimulating the respiratory centres.
As a cardiac stimulant, caffein may be used in any form of heart failure; the indications for its use are those which call for the employment of digitalis. It is superior to digitalis in never disagreeing with the stomach, in having no distinctive cumulative tendency, and in the promptness of its action. It is pronouncedly inferior to digitalis in the power and certainty of its action, and in the permanence of its influence once asserted. ”

“ Many patients cannot sleep for many hours after they have taken coffee or tea, as the cerebral stimulation of caffein is projected for hours after its ingestion. Caffein does not absorb so quickly and therefore does not act so quickly when taken in the form of tea and coffee as it does when taken as the drug or as a beverage which contains the alkaloid. Persons who are nervously irritable, excited and overstimulated cerebrally, with or without high blood pressure, should not take this cerebral and nervous excitant. ”

“ Caffein: This should not be given or allowed, even in the form of tea or coffee, to patients who have valvular lesions with perfect compensation, as it is a nervous and cardiac stimulant and may cause a heart to become irritable. It raises the blood pressure slightly, acts as a diuretic, and hence is often of great value when used medicinally. It should be ranked as a stimulotonic to the heart. It increases its activity, but gives it a little more strength. It will rarely slow a rapid heart; it will often stimulate a sluggish, slow heart; it may increase the irritability of an irritable heart. ”

“ It may thus be prescribed for hard drinkers to counteract the baleful excitability produced by alcohol; in fact, many topers taper off after a long debauch with coffee containing small amounts of alcoholic beverages. Considering its ability to counteract the slow intoxication of tobacco, it may be inferred that coffee is indispensable for hard smokers.
In general, the medicinal value of coffee may be said to be directly attributable to its caffein content, although its antiseptic properties are dependent upon the volatile aromatic constituents. ”

“ The tests were made with different doses of caffein in order to determine the limits of toxicity when the drug was administered by mouth.
Guinea pig 129. White and black male. Weight, 855 grams. Diet, oats and hay.
June 6: 2.20 p. m., 12 cc of 2 per cent caffein (0.28 gram per kilo) by mouth; 3 p. m., reflexes increased; 5 p. m., reflexes still more increased; no other symptoms.
June 7: 9 a. m., found dead; guinea pig passed 75 cc urine, which was almost colorless. Autopsy: Heart and blood vessels injected; lungs congested; small intestines congested; other organs apparently normal. ”

“ The injection of 0.16 gram of a 2 per cent solution of caffein into the jugular vein of a rabbit weighing 1,090 grams caused tetanus and death in two and one-half minutes, and 0.12 gram injected into a rabbit weighing 980 grams caused death in one minute. Much larger doses could be borne, however, when artificial respiration was resorted to. A dog which was given 3 grams of caffein survived when artificial respiration was performed. ”

“ The results of the experiments on rabbits show considerable variation in the toxicity of the single dose. Individuals differed so widely in their resistance to this drug that the same experiments had to be repeated many times with each method of administration before satisfactory conclusions could be drawn. This is strikingly illustrated in the experiments by intravenous injection in which a dose of nearly 0.2 gram per kilo was not fatal. Similar instances of exceptional resistance or of sensitiveness to caffein were observed when it was given in other ways. ”

“ Physiological Action.—Coffee belongs to the medicinal or auxiliary class of food substances, being solely valuable for its stimulant effect upon the nervous and vascular system. It produces a feeling of buoyancy and exhilaration comparable to a certain stage of alcoholic intoxication, but which does not end in depression or collapse. It increases the frequency of the pulse, lightens the sensation of fatigue, and it sustains the strength under prolonged and severe muscular exertion. ”

“ No difference was observed in the toxicity of caffein whether administered into gluteal or into the lumbar muscles. When introduced by this route the toxicity was found to be less by one-third than when it is injected into the peritoneal cavity, but is about 30 per cent more toxic than the subcutaneous injections. White or black rabbits were found to be less resistant to caffein than gray rabbits.
The resistance of the guinea pig to caffein, as of the rabbit, is greatest when given by mouth. ”

“ Experiments on cats were carried out by subcutaneous, intravenous, and rectal injections. The symptoms observed after the administration of 0.5 to 0.7 gram of caffein were the same as in rabbits except that the cats developed diarrhea when caffein was given and no anatomic lesions were found on autopsy. The effect of caffein on dogs indicated that in subjects of medium weight a dose of 0.5 gram given by mouth might produce restlessness and increased frequency of respiration, while the injection of the same amount intravenously into such animals may cause death. ”

“ The subjects used in these experiments were rabbits of medium size and were apparently young or at any rate were not very old. The series was planned for the study of the possible effect of diet on the toxicity of caffein when given for some time, and therefore oats were substituted for carrots, which had been fed in the previous work, as already stated. Caffein was given by mouth in the usual way, in 1 per cent solution, 100 mg. per kilo daily. Fourteen rabbits were used for these tests. Their weights were recorded daily and observations made at frequent intervals during the day. ”

“ If the points of the compasses are unequally heated, the sensation of two contacts becomes confused. An anaemic condition, or a state of venous con gestion, or the application of cold, or violent stretching of the skin, or the use of such substances as atropine, daturin, morphia, strychnine, alcohol, bromide of potassium, cannabin, and hydrate of chloral blunt sensibility. The only active substance said to increase it is caffein. Absolute sensitiveness, as indicated by a sense of pressure, has been determined by various methods. ”

“ Since the motor nerves retained their irritability even after the reflexes disappeared, he concluded that the loss of motion was due to the action of caffein on the nerve centers.
Binz11 (1878) reported experiments on dogs and also made some observations on man with caffein. The subcutaneous injections of 0.2 gram caffein may prove fatal to dogs, although some survive such [Pg 15] a dose. The toxic dose in man varies from 0.5 to 1.5 grams. Disturbance of the circulation, such as palpitation of the heart and fullness of pulse, restlessness, and diarrhea were the symptoms he observed. ”