strychnine, bitter alkaloid drug derived from the seeds of a tree, Strychnos nux-vomica, native to Sri Lanka, Australia, and India. It has been used as a rat poison for five centuries, and rat biscuits still remain a cause of accidental poisoning in humans. Strychnine is a potent stimulant of the spinal cord; it also increases the secretion of gastric juices and heightens sensory awareness. Strychnine poisoning is characterized by violent convulsions. It is treated by keeping the victim absolutely quiet and administering barbiturate sedatives and artificial respiration. See first aid.

Organic compound, a poisonous alkaloid obtained from seeds of the nux vomica tree of India and related plants of the genus Strychnos. It does not dissolve in water nor well in alcohol, and it has an intense bitter taste. It has been used in rodent poisons. Within 20 minutes after ingestion, it causes painful muscle contractions and convulsions, pulling the head back and arching the back; death usually results from respiratory muscle spasms. It is used in small doses by veterinarians as a stimulant.

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Strychnine ((British, U.S.), /-naɪn/ or /-nɪn/ (U.S.)) is a very toxic (LD₅₀ = 10 mg approx.), colorless crystalline alkaloid used as a pesticide, particularly for killing small vertebrates such as birds and rodents. Strychnine causes muscular convulsions and eventually death through 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 known. Its taste is detectable in concentrations as low as 1 ppm.

Pharmacology

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.

Although it is best known as a poison, small doses of strychnine were once used in medications as a stimulant, a laxative and as a treatment for other stomach ailments. A 1934 drug guide for nurses described it as "among the most valuable and widely prescribed drugs". Strychnine's stimulant effects also led to its use historically for enhancing performance in sports. Because of its high toxicity and tendency to cause convulsions, the use of strychnine in medicine was eventually abandoned once safer alternatives became available.

The dosage for medical use was cited as between "1/60th grain–1/10th grain", which is between 1.1 milligrams and 6.4 milligrams in modern measures. Normally the maximum dosage used was 3.2 mg, half of a "full dose". A lethal dose was cited as 1/2 a grain (32 mg), but people have been known to die from as little as 5 mg of strychnine.

See also

• avicide
• Strychnine poisoning

References