As per history of Toxicology, Poisons act in three ways.

  1. Local
  2. Remote 
  3. Combined 

In reality, poisons act in various ways. 

There are a lot of factors that affect the action of poisons are quantity or dose, form like the physical, mechanical combination, solubility, condition of the body, state of health, sleep and intoxication, tolerance. 

There are other factors also such as cumulative action, idiosyncrasy, mode of administration, etc. 

Factors that Modify the Action of Poisons 

1. Quantity or Dose 

Quantity is directly proportional to toxicity, i.e., If quantity increases, then toxicity also increases. According to dose, the mechanism of action may also change or vary. An example is that large doses of As cause death, whereas moderate doses and small doses produce irritant symptoms and therapeutic action. 

2. Form

  • Physical State 

Poisons are most active in the gaseous state than in the liquid and least in the solid-state.

  • Solubility 

Solubility of solids increases, then toxicity also increases. Due to acid secretion in the stomach, any insoluble salt becomes soluble and may become poisonous. Examples are Cu, lead carbonate, and As. 

  • Mechanical Combination 

Poisons combine with inert substances and may become harmless. 

  • Chemical Combination 

Sometimes two potent poisons may not be poisonous when taken together and don’t cause any harm. An example is a sulphuric acid and sodium hydroxide combination. 

  • Elemental State vs Salt

Some poisonous chemicals are not harmful in their elemental state, but their salts are poisonous, and some elements are Arsenic and copper. 

  • Dilution 

The more diluted the strong poison, the more it may become harmless. 

3. Condition of the Body 

  • Age of Victim 

Poisons have different effects on children and elders. Children are generally more sensitive towards drugs and poisons as compared to elders. 

Doses of a child are equal to ( age in years/age in years+12) * (adult dose). 

Elders will react differently to drugs and poisons. The reaction depends on pH of gastric, body fat, volume total body water 

  • Tolerance 

Any living organism can respond less to any fixed amount of a chemical than the previous occasion from the same dose. The reaction between poison and receptor decreases. Addicted persons can tolerate more quantities than fatal doses. 

  • State of Health 

A healthy person can tolerate poisons better than a diseased person. For example, carbon monoxide can kill at a much lower concentration of 25% to 30% in COAD, severe anemia, and emphysema. 

  • Sleep and Intoxication 

The person can get good sleep after taking the poison because of slower absorption. The action of poisons may be delayed. Because of the intoxication condition, action hastens if the poison is synergistic. If the action of poisons is delayed, then it is antagonistic. 

Categories: Toxicology


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