Strychnine

Strychnos Nux-Vomica

Strychnos nux-vomica is a naturally occurring source of strychnine, commonly known as Dog button, Poison nut. It’s known as “slang nut” or “slang Thai nut” in Cambodia and Thailand. This plant is native to Australia and southern Asia (India, Sri Lanka, and the East Indies). Strychnine is the principal alkaloid found in the strychnos plant (seeds) and is a strong spinal stimulant.

Principal

Strychnine and brucine are the main alkaloids, with the former being far more potent. It is a basic alkaloid that may be obtained from the seeds as an odourless, bitter-tasting white crystalline substance.

Toxic Parts

Leaves < Fruits < Seeds

Strychnine

Strychnine is a white, odourless, bitter crystalline powder that can be swallowed, inhaled (breathed in), or diluted in a solution and administered intravenously (injected directly into a vein).

Strychnine is a potent toxin; only a minimal quantity is required to cause significant side effects in humans. Strychnine poisoning can have extremely significant health consequences, including death.

Uses

Strychnine has been utilised as a medical treatment for a variety of illnesses for hundreds of years. Despite the fact that it is currently an uncommon poisoning agent, occasional ingestions still occur. Since the 16th century, it has been used as a rodenticide. It is also used to kill stray dogs. Strychnine is frequently discovered in combination with “street” substances including LSD, heroin, and cocaine.

Uses as Toxin

Strychnine is not a favourite poison for homicide for obvious reasons: bitter taste, severe character of symptoms which usually raises suspicion of foul play, and easy detectability in body fluids and tissues. However, from time to time, occasional occurrences are recorded. Children who chew on the seeds out of curiosity while playing or foraging in the countryside might become accidentally poisoned. Inadvertent ingestion of strychnine-containing rodenticides can also result in accidental poisoning. Strychnine is rarely used in suicide due to the agonising nature of dying.

Strychnine has been found in cocaine and heroin (it is a white powder that is used to “cut” the illegal substance). Strychnine poisoning symptoms appear quickly when breathed, snorted, or injected. Consider strychnine poisoning in a patient who has opisthotonic posturing as a result of illegal drug usage.

Mechanism

Strychnine inhibits postsynaptic glycine receptors, mostly in the spinal cord, resulting in painful, involuntary skeletal muscle spasms. Patients have episodic muscular spasms, normal mental state, and no post-ictal phase.

Fatal Dose

The severity of strychnine poisoning is determined by the amount and method of strychnine exposure, as well as the person’s health at the time of exposure.

Strychnine – 30 to 50 mg.

Strychnos seeds -1 to3 gm.

Signs & Symptoms

People who have been exposed to low or moderate amounts of strychnine by any method will experience the following signs or symptoms:

  • Agitation
  • Fear or apprehension
  • Capability to get shocked easily
  • Restlessness
  • Muscle spasms that cause pain and may result in a fever as well as kidney and liver damage
  • Uncontrollable neck and back arching
  • Rigid arms and legs
  • Jaw clenching
  • Soreness and discomfort in the muscles
  • Breathing difficulties
  • Dark urine
  • Initial consciousness and symptom awareness

People who have been exposed to large dosages of strychnine, within the initial 15 to 30 minutes may experience the following signs and symptoms:

  • Respiratory failure (inability to breathe), which may result to death
  • Brain death

Diagnosis

  1. TLC provides consistent qualitative results on gastric aspirate, urine, blood, or tissues. Urine and gastric aspirate are the finest specimens.
  2. HPLC generates precise quantitative data.
  3. Blood levels in the 0.1 to 0.3 mg/100 ml range are typically deadly.

Treatment

Treatment include eliminating the drug from the body (decontamination) as well as receiving supportive medical treatment in a hospital environment. Intravenous fluids (fluids injected straight into a vein), medicines for convulsions and spasms, and cooling treatments for high temperature, etc.

There is no antidote for strychnine toxicity.

Postmortem Findings

■ Early onset and disappearance of rigor mortis.
■ Postmortem caloricity.
■ Signs of asphyxia.
■ Frothing at mouth.
■ Dilated pupils.

Sources & References

Otter J, D’Orazio JL. Strychnine Toxicity. [Updated 2021 Aug 11]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK459306/

Singhapricha T, Pomerleau AC. A Case of Strychnine Poisoning from a Southeast Asian Herbal Remedy. J Emerg Med. 2017 Apr;52(4):493-495. 

Smith BA. Strychnine poisoning. J Emerg Med. 1990 May-Jun;8(3):321-5. 

Cole C, Jones L, McVeigh J, Kicman A, Syed Q, Bellis M. Adulterants in illicit drugs: a review of empirical evidence. Drug Test Anal. 2011 Feb;3(2):89-96.

Prat S, Hoizey G, Lefrancq T, Saint-Martin P. An unusual case of strychnine poisoning. J Forensic Sci. 2015 May;60(3):816-

Dittrich K, Bayer MJ, Wanke LA. A case of fatal strychnine poisoning. J Emerg Med. 1984;1(4):327-30.