This section is from the book "Dental Medicine. A Manual Of Dental Materia Medica And Therapeutics", by Ferdinand J. S. Gorgas. Also available from Amazon: Dental Medicine.
Caffeine is a proximate principle of feebly alkaloid power, generally prepared from the dried leaves of Camellia Thea, or from the dried seeds of Caffea Arabica. Caffeine was first extracted from coffee. One cup of good, well-made coffee contains one-half to one drachm of the empyreumatic oil, which has no physiological effects. It is in the form of colorless, silky, inodorless crystals, sparing soluble in alcohol, and in 75 parts of cold water, but much more soluble in 9.5 parts of boiling water.
It is a rapidly acting stimulant on the nervous system, its chief influence being on the brain and spinal column. By stimulating the muscles of the ' heart, it is supposed to increase the pulse rate and blood-pressure. It has a decided diuretic action, and counteracts the effects of narcotic remedies - it is valuable in opium poisoning, but is not a complete antidote. When taken into the stomach, it diffuses readily into the blood, and is eliminated principally by the kidneys and liver. Small doses increase the appetite, increasing peristalsis, and in some cases causing venous conjestion and hemorrhoids. It also acts as a powerful stimulant to the respiratory centre.
Caffeine is employed in neuralgia, migraine, hemicrania, dropsy, cholera infantum, asthma, cardiac disease, being a valuable cardiac stimulant. It often, however, produces insomnia to such a degree in cardiac disease, that its use has to be discontinued; if not, delirium, like that of alcohol, may ensue. The habitual use of coffee in some cases may also cause insomnia, palpitation, tremors, tinnitus aurium, gastralgia and emaciation. Caffeina alone cannot be used hypodermically owing to its decomposition in the presence of water.
Of Caffeine, gr. ij to gr. v: of Citrate of Caffeine gr. ij to gr. v.
For Facial Neuralgia, Migraine, etc.
Phenacetin .... Pulv. aromatic . . SlGna. - A powder every 2 or 3 hours.
For Facial Neuralgia, etc.
Caffeinae Citrat.. . . Ammonii bromidi . . Elix. guaranae . . . Signa. - A teaspoonful every hour or two until pain is relieved.