KKU doctor unravels effects of “cyanide”, a colorless substance , explaining what it is and how fatal it can be

  Hashtag # cyanide is continuously top Twitter Trending in Thailand this week, reiterating the socially interesting trend after news about mysterious deaths of many individuals doubtfully connected to cyanide. So what is this substance people are talking about? How dangerous is it? A specialized doctor of Khon Kaen University has an answer.


Assoc. Prof. Suda Wannaprasat, M.D., a doctor of the Department of Pharmaceutical Science, Faculty of Medicine, Khon Kaen University, explained that cyanide is a substance that is used in many industries. It can be of many forms, gaseous such as hydrogen cyanide that was used as weapon in World War II. In saline form such as potassium cyanide and sodium cyanide, it is found in borax or washing solution used with silver and gold items. Besides, it is found in plant such as raw cassava, which contains Linamarin that can be changed into cyanide within 3 to 24 hours. In addition, certain medicine can be changed into cyanide such as Sodium nitroprusside or pressure release medicine used with cases of hypertensive urgencies that require immediate reduction of blood pressure. Nevertheless, human body has an enzyme called Rhodanese, which is able to do away with cyanide. Meanwhile, doctors only prescribe this at little dose, leaving no effect on the patient. “Our body can get rid of cyanide provided it is in very small amount. Thus, a patient who is affected from cyanide can be said to have received a big amount that the body is unable to get rid of it until it results in illness and death.”

One can check the symptoms from cyanide:

Assoc. Prof. Dr. Suda stated that cyanide can enter human bodies by two major ways: inhaling and eating. A mere 200 mg intake of cyanide or inhalation of a mere 270 ppm can kill a person. The period of time of symptoms is also fast. In gaseous stage, it is only a matter of seconds, while potassium cyanide can show its effect in minutes. After entering the body, the action mechanism of cyanide will not make the patient green, for there is no oxygen deficiency. Cyanide, on the contrary, will stop the energy-building process at the cellular level, making the body unable to build energy. This means the cells that need much oxygen or energy such as brain and heart receive the impact first. The symptom begins at the brain, with nausea, unconsciousness, convulsion, and faint. The symptoms then aggravate to the heart, fast beating, high blood pressure at the first stage and heart stopping beating finally. The symptoms at the alimentary tract includes sickening, vomiting, diarrhea. The respiratory tract symptoms include slow breath and stopping breathing. Green body may happen at the last stage when there is failure of breathing and heart failure. Assoc. Prof. Dr. Suda admitted that it is rather difficult to notice cyanide. Potassium cyanide or sodium cyanide has no color. Cyanide gas smells like bitter almond , and it is difficult for a patient to notice. Only 40% of patients have reported to notice the smell.

‘ Use of antidote in time can increase chance of survival.

However, people should not be over panic, for the case that happened was not normal. Initially everyone can protect oneself by avoiding drinking water or eating food given by someone not familiar or unreliable, or unknown. If there are doubtful symptoms, one should see a doctor immediately  to receive antidote in time and be able to survive. There are specialists at Srinagarind Hospital who are able to diagnose symptoms from a patient’s account and from checking the symptoms including vein color and body pH. The Emergency Ward of the hospital is ready to provide sodium nitrite and sodium thiosulfate, which are supported by the Antidote Project and manufactured by Thai Red Cross. These are also available for patients receiving cyanide.


“Cyanide is a substance under control in laboratories and industrial factories. Purchase of cyanide must be recorded and reported in details. Therefore, the cases that were reported in the news are special cases that we should learn together so that we can be prepared for prevention and control of selling and buying of cyanide.”  

News: Phanit Khatanak


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