Obtaining a complete and accurate history is one of the most crucial steps in the initial diagnosis and subsequent management of the poisoned patients. This information can then be integrated with physical evidence, clinical examination, laboratory and toxicological data in designing a therapeutic approach. Such information may include patient data, product information, and nature of exposure. The basic treatment for acute poisoning, whether of drug or chemical, is mainly symptomatic and supportive. The four cardinal principles of good management are ① identification of the causative drug or chemical as quickly as possible, ② evacuation of the poison from the stomach, except when contraindicated, ③ administration of an antidote if available, and ④ symptomatic and supportive therapy as indicated. Management in most cases of toxicity consists of supportive care, symptomatic treatment, and avoidance of exposure to the toxic material. In cases of life-threatening toxicity, maintenance of cardiopulmonary function and fluid and electrolyte balance are important. There are limited specific methods of treatment, or "antidotes". Use of oxygen counters the foxic effect and enhances the elimination of carbon monoxide. In cases acute cyanide of hydrogen sulfide poisoning, nitrites may be used to generate formation of cyanmethemoglobin or sulfmethemoglobin. Hydroxocobalamin can also be used as an antidote for cyanide. Atropine and pralidoxime can be life-saying in reversing the acute cholinesterase-inhibiting effects of organophosphate pesticides. Chelating agents may reverse acute toxicity caused by some metals.