First, read the English article below.

Over the counter emetics, or medicines that can make you throw up, should be avoided unless a medical professional directs you to take some as a last resort. Ipecac syrup, for instance, was once commonly used to induce vomiting. However, it has been shown that medications such as these can complicate treatment for poisoning. In fact, ipecac is no longer produced for over-the-counter sales. While salt water is a classic home remedy to induce vomiting, it may actually pose a risk to a poisoning victim.  This is because drinking salt water can push toxic substances further into the digestive track and speed up absorption of the substance in the process. Furthermore, drinking large amounts of salt water may cause serious health complications, including death. Folk methods of inducing vomiting include drinking mustard or raw eggs, or eating large amount of food. The safety and effectiveness of these methods has not been proven. For instance, eating a large amount of food to induce vomiting may actually speed up absorption of a poisonous substance. There are a handful of substances that can induce vomiting but are not recommended. These include activated charcoal, atropine, biperiden, diphenhydramine, doxylamine, scopolamine, copper sulfate, bloodroot, lobelia tincture , and hydrogen peroxide. 

Now, please write a short abstract for it in Vietnamese. Abstract:
Tránh dùng thuốc gây nôn trừ khi có chỉ định. Không uống nước muối. Thận trọng khi dùng các liệu pháp tại nhà. Tránh sử dụng các chất tiềm ẩn nguy cơ gây hại.