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..
Gastro-intestinal tract. - Tincture of nux vomica is very largely given with excellent results as a bitter stomachic and carminative, especially in cases in which the feebleness of digestion is merely part of generally feeble health. Twenty drops of tincture of nux vomica in a wineglass of hot water will frequently at once check gastro-intestinal fermentation. A mixture of diluted hydrochloric acid, gentian and nux vomica is of great service in these cases. As the digestion improves, the general health improves. Because of its power to stimulate peristalsis nux vomica is a valuable drug for cases of constipation in which the contractile strength of the muscular coat of the intestine is weak; usually this is a part of a general weakness of the whole body. The constipation of anaemia, which can be very successfully treated by a pill of extract of nux vomica and ferrous sulphate, is a good instance of this variety of constipation.
Circulation. - In cases of heart disease in which digitalis is inadmissible, nux vomica and strychnine are excellent cardiac stimulants, and for this purpose they may be combined with caffeine. Patients almost dead from failure of the heart in the course of chronic cardiac disease may sometimes be brought around by the subcutaneous injection of strychnine.
Respiration. - Strychnine may be combined with expectorants, because it stimulates the respiratory centre; and it is extremely serviceable when from any cause, such as severe bronchitis, the respirations are feeble and shallow. It is also useful in pneumonia when death is imminent from dilatation of the right heart. In this condition it should be administered hypodermatically and at frequent intervals.
Nervous system. - It has been given for a number of nervous diseases, but with no constantly good results, for when the disease is not in the anterior cornua, strychnine is hardly indicated; and if it is in this part of the cord, it is doubtful whether it is advisable to stimulate the part of the body which is diseased.
In about an hour after a poisonous dose the patient begins to feel uneasy from a sensation of impending suffocation. The tetanic convulsions then commence with great violence, nearly all the muscles of the body being affected at once. The limbs are thrown out, the hands are clenched, the head is jerked forwards and then bent backwards, and the whole body is perfectly stiff from the violence of the contractions. The pulse is very rapid; the temperature may rise. Hearing and sight are acute. The convulsion lasts a minute or two, then the muscles relax, and the patient feels exhausted and sweats all over. The intermission is short, convulsions soon come on again, and again there is a relapse to the state of muscular relaxation. The convulsions now rapidly increase in severity, and owing to the violent contractions of the muscles of the back, the patient is in the position of opisthotonos, resting on his head and his heels. The abdominal muscles are as hard as a board, the chest is fixed, the face becomes livid, the eyeballs are staring. The contraction of the muscles of the face causes a risus sardonicus; but those of the jaw are not affected till near the end; this aids in distinguishing strychnine poisoning from tetanus. Consciousness is retained till the last. The slightest noise or even a bright light will reflexly bring on the convulsions, which may jerk the patient out of bed. Ultimately he dies from exhaustion and asphyxia. The smallest dose of strychnine known to have killed is half a grain; .03 gm.
The usual appearances of death by asphyxia are seen.
Strychnine poisoning is liable to be confounded with tetanus, but in this disease symptoms come on more slowly, the muscles of the jaw are implicated very early, and there is continuous muscular rigidity with paroxysmal exacerbations, but never complete muscular relaxation.
Give emetics (see p. 139), particularly apomorphine bydro-chlorate hypodermatically, or wash out the stomach if. the patient is seen early enough for the passing of the tube not to cause spasm. The stomach may be washed with solution of potassium permanganate as for opium poisoning, but it is not so effective. Inject large doses of potassium bromide and chloral per rectum. Use amyl nitrite inhalations, and if possible artificial respiration.
In a sense strychnine is antidotal to chloral and morphine, but it is not a strict antidote, for they act chiefly on the cerebrum. Still chloral is valuable in strychnine poisoning, and although the antagonism with Calabar bean and gelsemium is more accurate, as both depress the anterior cornua, yet they are of very little use in strychnine poisoning. Chloroform is the most practical antidote to strychnine.