Cannabis Indica,—Indian Hemp.
Source and Composition. The flowering tops of the female plant of Cannabis Sativa (nat. ord. Urticaceae), grown in the East Indies. It contains a resin named Cannabin, and a volatile oil, from the latter of which are obtained Cannabene, a light hydrocarbon, and Cannabene Hydride, a crystalline body.
Cannabis Americana, which was official in the U. S. P. 1880, is the same plant, grown in the Southern States, and is specifically identical with the Indian plant, but of much less powerful action. Cannabis should not be confounded with the so-called " Indian or Canadian Hemp," which is Apocynum Cannabinum, an entirely different plant, having diuretic properties, but no others of marked character.
- Extractum Cannabis Indicae,—Dose, gr. 1/4-j, if active.
- Extractum Cannabis Indicae Fluidum,—alcoholic, and only miscible with aqueous fluids in form of emulsion, otherwise the active resin will separate and float to the top. Dose, ♏j-x, but much more may be given without untoward results.
- Tinctura Cannabis Indicae,—15 per cent. Dose, ♏x-ʒj.
- *Cannabini Tannas, Cannabin Tannate,—Dose, gr. ij-x, in pill.
Preparations of Hemp commonly used in the East are—
- Churrus,—an impure resin, obtained by rubbing the leaves together.
- Gunjah,—the dried leaf as sold in the bazaars for smoking purposes.
- Siddhi, Hashish or Bhang,—an Arabian confection, containing the leaves mixed with aromatics and various fruits.
Physiological Action. Cannabis is antispasmodic, analgesic, anaesthetic and narcotic, a cerebro-spinal stimulant, and a powerful aphrodisiac. It increases intellectual and motor activity, stimulates the vaso-motor nerves, raising the arterial tension, and depresses sensation.
Large Doses cause a pleasurable intoxication, during which the traits peculiar to the individual are exalted; the ideas follow each other so rapidly as to produce a sense of great prolongation of time, minutes seeming as if hours or even days. With this occurs increased sexual desire, great muscular activity, and sensations of double consciousness and enormous dimensions; the sight and hearing are exalted, the pupils dilated, anaesthesia sets in, the reflexes are lowered by stimulation of inhibition (Setschenow's centre ?); and if the dose be a heavy one a cataleptic state is induced. Sleep or coma follows, according to the size of the dose, but death has never been caused by this drug.
After-effects are dullness, heaviness, vertigo, headache, and confused thought but no nausea, no vital depression, or constipation. Repeated use of the drug produces mental weakness and impotence, the result of over-stimulation. It causes a ravenous appetite, and increases the energy of the uterine muscular fibre, but has no power to initiate uterine contractions.
Therapeutics. Cannabis was formerly much used as an anodyne and hypnotic, and as an anaesthetic during surgical operations. It is out of fashion now, but very useful in—
- Migraine, or sick-headache,—in which it often prevents the recurrence of the attacks, seeming to act specifically on Ringer's migraine centre.
- Neuralgia,—full doses during the attack, smaller doses in the intervals.
- Uterine Affections, as chronic metritis, subinvolution, menorrhagia, dysmenorrhoea, etc.,—its powers as an anodyne and stimulant of the uterine muscular fibre render it a very efficient agent.
- Traumatic Tetanus, Paralysis Agitans, etc.,—large doses are required in order to lower reflex activity.
- Delirium Tremens,—if any hypnotic be used, Cannabis is one of the best.
- Dysuria and retention of the urine,—are often relieved by it. In spasm of the bladder and other painful affections of that organ it will be found a most efficient remedy, if administered in full doses.
- Impotence of functional character,—Cannabis is a very useful remedy and may be well combined with Ergot and Nux Vomica.
- Gonorrhoea,—it lessens the discharge, inflammation, burning pain and restlessness, and allays chordee. The tincture of the American plant is very useful here, being fully as efficient as Copaiba or Sandal, and much more agreeable. It should be prepared from the fresh plant, and given in 3-5 drop doses 3 or 4 times a day, after the subsidence of the acute symptoms.
- Insomnia, especially that of acute mania,—the Tannate of Cannabin is recommended as a powerful hypnotic, but not a dangerous one, neither disturbing the secretions nor leaving unpleasant after-effects, if used in proper dosage, viz.,—gr. ij-x, the average being gr. v.
A Compend of Materia Medica, Therapeutics, and Prescription Writing, 1902, by Sam'l O. L. Potter, M.D., M.R.C.P.L.