1. Introduction Flashcards
Define toxicology.
The study of the adverse effects of xenobiotics on biological and ecological systems.
Define Xenobiotic.
Any substance that is foreign to a biological system
What’s the difference between a toxicant and a toxin?
Toxicant: a chemical that is produced by man and after introduction into the environment produces harmful effects.
Toxin: a harmful substance produced within a cell or an organism, e.g., snake venom.
How are toxic substances classified? give examples
Toxic substances can be classified according to why the chemicals exist:
- Chemical warfare agents
- Pesticides
- Environmental pollutants
- Household poisons
- Drugs
- Food additives
- Cosmetics
- Industrial chemicals
Give examples of plants that produce toxins.
- Star of Foxglove
- Belladonna
- Poison ivy
- Poison oak
- Yew
- Oleander
- Wisteria
- Hemlock
Can natural substances such as plants be toxicants? Give examples.
Yes, just because it is natural, it doesn’t mean it can’t be toxic.
Ex: star of foxglove -> Digoxin
Belladonna -> atropine
Yew -> Taxol
Describe the differnece between toxicology and pharmacology.
Toxicology: Undesired effects of therapeutic agents.
- Actions of poisons / toxins that would not be used as therapeutic agents
- Effects of chemicals in/on the environment - indirect effects on human health
Pharmacology: Desired effects of therapeutic agents.
What are the branches of toxicology?
- Clinical Toxicology (hospital setting)
- Forensic Toxicology (Medical Examiner’s office)
- Industrial Toxicology
- Environmental Toxicology (Government, University)
- Biochemical and Molecular Toxicology (University)
- Product Development Toxicology (Corporate setting)
- Regulatory Toxicology (industry and government settings)
What is the distribution of chemicals in commerce in order from biggest to smallest?
1. Industrial ~80,000 on TSCA (toxic substances control act) Inventory No specific data requirements for PMNs (pre-manufacture notice)
- Pesticides
~2000 Active Ingredients (AI)
FIFRA requires data (Federal Insecticide, Fungicide, and Rodenticide Act) - Drugs, Cosmetics, Food Additives
~2,000 AI
Federal Food, Drug, and Cosmetic Act requires data
What is the purpose of mechanistic toxicology? Who mainly researches it?
To identify and understand cellular and molecular mechanisms by which chemicals exert toxic effects on organisms.
Done by academic research.
What is the purpose of regulatory toxicology?
Who mainly researches it?
Assess risk prior to marketing HC, FDA, EPA, OSHA.
Mainly researched by the government.
What is descriptive toxicology?
Who mainly researches it?
Toxicity testing, Safety evaluation, and Regulatory requirements.
It is mainly researched by the industry.
Who is the father of Chinese medicine? What did he do?
- Emperor Shen Nung
- Wrote Pen Ts’ao - the Great Herbal or Chinese Materia Medica
What is Ebers papyrus?
Ebers papyrus, Egyptian compilation of medical texts dated about 1550 bc, one of the oldest known medical works.
- recognizes many poisons such as:
- hemlock
- aconite (helmet flower)
- Chinese arrow poison,
- opium
- heavy metals (lead, copper and antimony)
Explain the history of pharmacology that took place in Rome.
King Mithridates VI (Rome, 132–63 BC)
- did acute toxicity experiments on accused criminals
- claimed to have discovered a mixture of antidotes against all poisons
- treated himself with a mixture of 36 such chemicals
- Mithridatic = antidotal or protective mixture