1. To remove the poison from the digestive tract, or neutralise it or render it insoluble by the administration of suitable antidotes.
2. To overcome the effects of that which has been absorbed.
3. To promote its elimination.
4. To alleviate dangerous symptoms, and endeavour to keep the patient alive until the effects of the poison have passed off.
To forcibly empty the stomach, emetics may be administered or other means used to induce vomiting, or the stomach pump or tube may be employed.
Suitable emetics are sulphate of zinc in thirty-grain doses dissolved in warm water, a dessert-spoonful of mustard in half a pint of warm water, ipecacuanha wine in tablespoonful doses, copious draughts of hot water. Tartar emetic and sulphate of copper should be avoided, except in cases of phosphorus poisoning, when the latter may be used. The hypodermic injection of ⅒ grain of apomorphine is a very useful emetic, especially in cases of narcotic poisoning. Irritation of the fauces with the finger or a feather promotes vomiting, and may be useful in the absence of an emetic.
The stomach tube or pump is most useful in that it is under the control of the operator and enables him to thoroughly wash out the stomach. After passing the tube, previously lubricated with vaseline or glycerine, through the œsophagus down to the stomach, a pint of warm water should be first injected before withdrawing any of the contents. By alternate injection of water and its withdrawal, the stomach may be efficiently cleansed, and at the same time solutions of suitable antidotes may be passed into it. It must be remembered that neither the stomach pump, syphon tube, nor emetics, are to be used in cases of poisoning with corrosives, with the exception of carbolic acid. The tube should be used with great caution in cases of irritant poisoning.
Antidotes are remedies which counteract the effects of poisons. They act mechanically, e.g. flour and water, chalk mixture; chemically, as magnesia and chalk in mineral acid poisoning, alkaline sulphates in lead and barium poisoning; and physiologically, as antagonists, such as morphine and atropine, atropine and physostigmine, strychnine and chloral hydrate.
To counteract the effects of the portion of the poison absorbed, special treatment is necessary: purges and diuretics may be called for; artificial respiration may be necessary; cardiac depressants require cardiac stimulants; the cold douche as a restorative and external warmth are desirable in certain cases. Sedatives may be administered to alleviate convulsive seizures. Tracheotomy may be required in cases with laryngeal complications; and pain, exhaustion, excessive vomiting or purging are to be treated by appropriate remedies.