This section is from the book "Materia Medica Pharmacy, Pharmacology And Therapeutics", by W. Hale White. Also available from Amazon: Materia Medica Pharmacy, Pharmacology And Therapeutics..
A mixture of alkaloids obtained from the seed of Asagrcea officinalis (Schlechtendal et Chamisso, Lindley (nat. ord. Liliaceae).
Mexico to Venezuela.
1) The seed is exhausted with Alcohol, and the Alcohol recovered by distillation. (2) The residuary liquid is diluted with water to precipitate the resins and filtered. (3) Ammonia is added to the filtrate when veratrine is precipitated. (4) It is then re-dissolved, decolorized, and re-precipitated.
A white or grayish-white, amorphous or semi-crystalline powder, odorless, .but causing intense irritation and sneezing when even a minute quantity reaches the nasal mucous membrane; having an acrid taste, and leaving a sensation of tingling and numbness on the tongue; permanent in the air.
Very slightly soluble in water; soluble in 3 parts of Alcohol; also soluble in 6 parts of Ether, and in 2 parts of Chloroform. Dose, 1/30 to 1/10 gr.; .002 to .006 gm.
1. Oleatum Veratrinae. - Oleate of Veratrine. Veratrine, 2; Oleic Acid, 98.
Veratrine, if it is applied to the unbroken skin, and especially if it is rubbed in, produces tingling and numbness, followed by a sensation of coldness, and anaesthesia to pain, touch, and temperature. Given subcutaneously, it causes violent pain and irritation.
Gastro-intestinal tract. - Inhalation of the minutest portion causes great irritation of the mucous membrane of the nose, violent sneezing, and a free discharge of mucus, which may be bloody. A minute portion upon the tongue gives rise to burning pain and profuse salivation. On arriving at the stomach and intestine it produces great epigastric pain, vomiting and diarrhoea. These results also occur if it is given subcutaneously.
Blood. - Veratrine is quickly absorbed. It is not known to affect the living blood, but it kills the white corpuscles in drawn blood.
Heart. - It acts directly on the cardiac muscle as it does upon voluntary muscle; that is to say, the contractions of the heart become fewer, but each lasts a very long while until ultimately the heart stops in systole. It also acts on the vagus as on spinal nerves, the functional activity being first exalted, and this is partly the reason of the slowing of the heart; afterwards the vagus is depressed, but this does not cause a quickening of the pulse because of the action of the veratrine on the cardiac muscle, but it may make the beat irregular. The blood-pressure at first rises from the increased force of the beat, but when the heart becomes very slow it falls. Possibly these effects are also, in part, owing to the action of the drug on the vaso-motor centres.
Respiration. - Small doses quicken respiration, large ones retard it, producing long pauses, and finally arresting it. These results are probably due at first to stimulation, and afterwards to paralysis of the ends of the vagus in the lung, and to paralysis of the respiratory centres. The temperature is lowered.
Nervous system. - The brain is unaffected, and probably vera-trine has no influence on the spinal cord. Motor nerves are first excited and then paralyzed; and the same is true of sensory nerves and their endings, but here the primary stimulation is very marked, hence the pain produced by the local inunction of veratrine.
Muscles. - The effect of veratrine is pecular and characteristic. In animals to which it has been given, or in excised muscles to which it is applied, it is found that the period during which a single contraction lasts is enormously prolonged. If a tracing of the contraction be taken it will be seen that the latent period and the time of the ascent of the curve are unaltered, that the height is greatly increased and the descent is extraordinarily extended. This is a genuine lengthened contraction, which is neither rigor nor tetanus, but it almost exactly resembles the contraction of the muscles met with in Thomsen's disease. This effect of veratrine disappears if the muscle is cooled.
Veratrine as an oleate or ointment has been much used as an inunction for neuralgia, and sometimes it succeeds admirably, generally in the same class of cases as are benefited by the local application of aconite. See also amyl colloid, p. 441.
It is rarely given internally, as it has such a powerful and pecular action on the heart.