(A) metal poisoning antidote: these drugs are mostly chelating agents, commonly used are ammonia carboxyl chelating agents and mercapturic chelating agents. (1) Sodium calcium edetate: This product is the most commonly used aminocarboxyl chelator, which can form stable and soluble metal chelates with various metals and be discharged from the body. It is used for the treatment of lead poisoning. 1g is added to 250ml of 5% glucose solution, diluted and injected intravenously once a day for 3 days as a course of treatment, and can be repeated after an interval of 3 to 4 days. ②Dimercaptopropanol: This drug contains active sulfhydryl (-SH), sulfhydryl antidote into the body can form non-toxic, difficult to dissociate but soluble chelate with certain metals excreted by urine. In addition, it can also seize the heavy metals that have been combined with the enzyme, so that the enzyme can be revitalized, thus achieving detoxification. It is used to treat arsenic and mercury poisoning. Acute arsenic poisoning treatment dose: day 1~2, 2~3mg/kg, every 4~6 hours, intramuscular injection; day 3~10, 2 times a day. Adverse effects of this drug include nausea, vomiting, abdominal pain, headache or palpitations. ③Dimercaptopropanesulfonic acid sodium salt (dimercaptopropanesulfonic acid sodium salt: the effect is similar to dimercaptopropanol, but the efficacy is better and the adverse reactions are less. It is used to treat mercury, arsenic, copper or antimony poisoning. In case of mercury poisoning, 5ml of 5% sodium dimercaptopropanesulfonate should be injected intramuscularly once a day for 3 days as a course of treatment, and the drug can be repeated after an interval of 4 days. ④Dimercaptobutyric acid disodium salt: used for the treatment of antimony, lead, mercury, arsenic or copper poisoning. In acute antimony poisoning with arrhythmia, 2.0g should be injected slowly intravenously after dilution with 10-20ml of water for injection for the first time, and 1.0g once an hour thereafter for 4-5 times. Wu Shengkai, Emergency Department, Puning People’s Hospital (b) an antidote for methemoglobinemia: methylene blue (methylene blue): small doses of methylene blue can reduce methemoglobin to normal hemoglobin, used to treat methemoglobinemia caused by nitrite, aniline or nitrobenzene poisoning. Dose: 1% methylene blue 5-10ml (1-2mg/kg) diluted intravenous injection, according to the condition can be repeated application. It is easy to cause tissue necrosis when the drug is injected extravasated. (C) Cyanide poisoning antidote: Immediately after poisoning, inhale isoamyl nitrite. Following that, 10ml of 3% sodium nitrite solution is slowly injected intravenously. Immediately thereafter, 50ml of 50% sodium thiosulfate is injected slowly intravenously. The right amount of nitrite oxidizes hemoglobin to produce a certain amount of methemoglobin, which forms cyanide methemoglobin with cyanide in the blood. Methemoglobin also seizes cyanide ions that have been bound to oxidized cytochrome oxidase. The cyanide ions interact with sodium thiosulfate and are converted to the less toxic thiocyanate and excreted. (iv) Mepizole: It and ethanol are effective antidotes for the treatment of ethylene glycol and methanol poisoning. Both mepizole and ethanol are ethanol dehydrogenase (ADH) inhibitors, with the former acting more strongly than the latter. Ethylene glycol can cause renal failure, and methanol can cause visual impairment or blindness. Administration of mepyridamole before the manifestation of poisoning after exposure to methanol and ethylene glycol can prevent its toxicity; administration after the appearance of poisoning symptoms can stall the progression of the disease. When renal damage is not severe in patients with ethylene glycol poisoning, the application of mepizole may avoid hemodialysis. Intravenous loading dose of 15 mg/kg with more than 100 ml of saline or 5% glucose solution is infused for more than 30 minutes. The maintenance dose is 10 mg/kg every 12 hours for 4 times. (E) Octreotide: It can reduce the role of pancreatic β-cells and is used to treat hypoglycemia caused by sulfonylureas over the most. It inhibits insulin secretion 2 times stronger than growth inhibitor. It is prohibited for those who have allergic reaction. Adult dose 50-100μg, subcutaneous injection or intravenous infusion every 8-12 hours. (F) Hyperglycemia: It can induce the release of catecholamines, and is an antidote to the poisoning of β-blockers and calcium channel blockers, and can also be used in the overdose of procaine, quinidine and tricyclic antidepressants. The main indications for application are bradycardia and hypotension. The first dose is 5 to 10 mg intravenously. The above dose can be repeatedly injected. Maintenance dose infusion rate 1-10mg/h. Common adverse effects are nausea and vomiting. (VII) Central nervous system depressant antidote: 1) Naloxone: is an antidote to opioid narcotics, and has a specific flickering effect on the respiratory depression caused by narcotic analgesics. In recent years, clinical findings, naloxone not only on acute alcohol poisoning has a hypnotic effect, on a variety of sedative-hypnotic drugs, such as diazepam (diazepam) and other poisoning also has a certain effect. When the body is in a state of stress, it induces the release of β-endorphins from the pituitary gland, which can cause cardiopulmonary dysfunction. Naloxone is an opioid receptor antagonist, which can antagonize the adverse effects of β-endorphin on the body. Naloxone 0. 4 to 0. 8 mg is given intravenously. Repeat after 1 hour in critically ill patients. 2) Flumazenil: It is the antidote for benzodiazepine poisoning.