Toxicokinetics

This section covers the key components of toxicokinetics

Toxicokinetics

  • Definition: The study of the kinetics of toxic substances in the body, focusing on ADME processes
  • Purpose: To understand how the body handles toxic substances, predict their distribution and effects, and guide treatment strategies

Toxic Effects, Signs, and Symptoms

  • Dose-Response Relationship
    • Describes the relationship between the amount of exposure to a toxic substance and the severity of the effects
  • Target Organs
    • Some toxins selectively target specific organs
  • Mechanisms of Toxicity
    • Cellular necrosis, apoptosis, oxidative stress, mitochondrial dysfunction, inflammation, neurotoxicity, carcinogenesis, teratogenesis
  • Signs and Symptoms
    • Vary based on the substance, exposure route, and individual factors
  • Common Toxic Syndromes (Toxidromes)
    • Cholinergic, anticholinergic, sympathomimetic, opioid, sedative-hypnotic

Metabolism and Excretion

  • Metabolism (Biotransformation)
    • Process by which the body chemically alters toxins
    • Primary site: Liver
    • Purpose: Detoxification (convert to less harmful) or bioactivation (convert to more harmful)
    • Phases:
      • Phase I: Oxidation, reduction, hydrolysis (CYP enzymes)
      • Phase II: Conjugation (glucuronidation, sulfation, etc.)
    • Factors Affecting Metabolism:
      • Genetics, age, liver and kidney function, drug interactions
  • Excretion
    • Process by which the body eliminates toxins
    • Primary Routes:
      • Kidneys (urine)
      • Liver (bile)
    • Renal Excretion:
      • Glomerular filtration, tubular secretion, tubular reabsorption
    • Factors Affecting Excretion:
      • Renal and liver function, pH

Clinical Significance

  • Understanding Toxicokinetics Helps In
    • Predicting the toxicity of substances
    • Assessing individual susceptibility to toxic effects
    • Developing effective treatments for poisoning
    • Designing strategies for preventing exposure to toxic substances