Chemicals that cause loss of consciousness in a short period of time are often called **anesthetics**or **sedatives**. They quickly reduce or inhibit consciousness by affecting the central nervous system. Here are some common chemicals： ### 1. **Volatile anesthetics** - **Ether (Ether)**: An early anesthetic that can quickly cause loss of consciousness through inhalation. -**Halothane (Halothane)**, **Isoflurane (Isoflurane)**, **Sevoflurane (Sevoflurane)**: Inhalation anesthetics commonly used in modern anesthetic surgery can cause patients to lose consciousness in a short period of time. ### 2. **Gas anesthetic** -**Nitrous oxide (Nitrous Oxide, commonly known as "laughing gas”)**: After inhalation, it can quickly produce sedative and anesthetic effects, but it requires a higher concentration to cause loss of consciousness. -**Xenon (Xenon)**: A rare gas that has an anesthetic effect, but is used less frequently. ### 3. **Intravenous anesthetic** -**Propofol (Propofol)**: A fast-acting intravenous anesthetic, commonly used to induce anesthesia, which can cause loss of consciousness within a few seconds. -**Sodium Thiopental (Thiopental)**: An ultra-short-acting barbiturate that quickly causes loss of consciousness after intravenous injection. -**Ketamine (Ketamine)**: An isolated anesthetic that can cause loss of consciousness and analgesia in a short period of time after intravenous injection. ### 4. **Sedative and hypnotic drugs** -**Benzodiazepines (such as diazepam, Midazolam)**: High doses can cause loss of consciousness, but the effect is slower. -**Barbiturates (such as pentobarbital)**: High doses can quickly cause loss of consciousness. ### 5. **Other chemical substances** -**Cyanide (Cyanide)**: By inhibiting cellular respiration, it can cause loss of consciousness and death in a very short time. -**Carbon Monoxide (Carbon Monoxide)**: By binding to hemoglobin, it reduces the oxygen carrying capacity of the blood, resulting in loss of consciousness. ### Precautions Most of these chemicals are highly dangerous, and improper use may lead to serious health consequences and even death. **Under no circumstances should you try to use these substances** unless under the supervision of a professional medical professional. If you or someone else encounters an emergency, please contact a medical professional or call an emergency number immediately.