Strychnine (pronounced /strkniːn/ (British) or /strknan/ (U.S.)) is a very toxic (LD50 = 1 mg/kg), colorless crystalline alkaloid used as a pesticide, particularly for killing small vertebrates such as rodents. Strychnine causes muscular convulsions and eventually asphyxia or sheer exhaustion. The most common source is from the seeds of the Strychnos nux-vomica tree. Strychnine is one of the most bitter substances in the world. Its taste is detectable in concentrations as low as 1 ppm.
Strychnine acts as a blocker or antagonist at the inhibitory or strychnine-sensitive glycine receptor (GlyR), a ligand-gated chloride channel in the spinal cord and the brain.
Strychnine poisoning in humans
Strychnine poisoning can be fatal to humans, and can be introduced to the body by inhalation, swallowing or absorption through eyes or mouth. It produces some of the best-known, most dramatic, terrifying, and painful symptoms imaginable. For this reason, strychnine poisoning is often used in literature and film.
Ten to twenty minutes after exposure, the body’s muscles begin to spasm, starting with the head and neck. The spasms then spread to every muscle in the body, with nearly continuous convulsions, and get worse at the slightest stimulus. They progress, increasing in intensity and frequency until the backbone arches continually. Death comes from asphyxiation caused by paralysis of the brain’s breathing apparatus, or by exhaustion from the convulsions. At that time, the body “freezes,” even in the middle of a convulsion. Rigor mortis sets in immediately, with the eyes left wide open.
Treatment involves giving depressants, such as intravenous diazepam, to control the convulsions, and giving an activated charcoal infusion to drink, which serves to absorb any poison remaining within the digestive system. If the patient lives 24 hours, recovery is probable.
Small doses of strychnine were sometimes used in over-the-counter medications as a laxative and as a treatment for other stomach ailments; this practice was eventually abandoned with the proliferation of safer alternatives.
Strychnine poisoning in animals
Strychnine poisoning in animals occurs usually from ingestion of baits designed for use against rodents (especially gophers and moles) and coyotes. Rodents baits are commonly available over-the-counter, but coyote baits are illegal in the United States. However, since 1990 in the United States most baits containing strychnine have been replaced with zinc phosphide baits.[1] The most common domestic animal to be affected is the dog, either through accidental ingestion or intentional poisoning. An approximate lethal dose for a dog is 0.75 mg per kg body weight.[2] For a 0.3% strychnine bait, five grams could be enough to kill a twenty kilogram dog.
The onset of symptoms is 10 to 120 minutes after ingestion.[2] Symptoms include seizures, a “sawhorse” stance, and opisthotonus (rigid extension of all four limbs). Death is usually secondary to respiratory paralysis. Treatment is by detoxification using activated charcoal, pentobarbital for the symptoms, and artificial respiration for apnea.
Strychnine in drugs
There is a common but wrong urban legend that strychnine is added to drugs like LSD or that strychnine is present in the peyote cactus. The dose of LSD is so small that it could not be mixed with a toxic amount of strychnine, even if strychnine made up an entire blotter square.
Copyright: Wikipedia information about Strychnine – This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Strychnine". More from Wikipedia