Toxicology

Revision as of 17:10, 6 February 2009 by Scott Everett (talk | contribs)
Jump to navigation Jump to search
Part of a series on
Toxicology and poison
Toxicology (Forensic)  · Toxinology
History of poison
(ICD-10 T36-T65, ICD-9 960-989)
Concepts
Poison · Venom · Toxicant (Toxin)  · Antidote
Acceptable daily intake · Acute toxicity
Bioaccumulation · Biomagnification
Fixed Dose Procedure · LD50 · Lethal dose
Toxic capacity · Toxicity Class
Toxins and venoms
Neurotoxin · Necrotoxin · Hemotoxin
Mycotoxin · Aflatoxin · Phototoxin
List of fictional toxins
Incidents
Bradford · Minamata · Niigata
Polonium · Bhopal
2007 pet food recalls
List of poisonings
Poisoning types
Elements
Toxic metal (Lead · Mercury · Cadmium · Antimony · Arsenic · Beryllium · Iron · Thallium· Fluoride · Oxygen
Seafood
Shellfish (Paralytic · Diarrheal
Amnesic)
 · Ciguatera · Scombroid
Tetrodotoxin
Other substances
Pesticide · Organophosphate · Food
Nicotine · Theobromine · Carbon monoxide · Vitamin · Medicines
Living organisms
Mushrooms · Plants · Venomous animals
Related topics
Hazard symbol · Carcinogen
Mutagen · List of Extremely Hazardous Substances · Biological warfare · Food safety

Template:Tnavbar

WikiDoc Resources for Toxicology

Articles

Most recent articles on Toxicology

Most cited articles on Toxicology

Review articles on Toxicology

Articles on Toxicology in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Toxicology

Images of Toxicology

Photos of Toxicology

Podcasts & MP3s on Toxicology

Videos on Toxicology

Evidence Based Medicine

Cochrane Collaboration on Toxicology

Bandolier on Toxicology

TRIP on Toxicology

Clinical Trials

Ongoing Trials on Toxicology at Clinical Trials.gov

Trial results on Toxicology

Clinical Trials on Toxicology at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Toxicology

NICE Guidance on Toxicology

NHS PRODIGY Guidance

FDA on Toxicology

CDC on Toxicology

Books

Books on Toxicology

News

Toxicology in the news

Be alerted to news on Toxicology

News trends on Toxicology

Commentary

Blogs on Toxicology

Definitions

Definitions of Toxicology

Patient Resources / Community

Patient resources on Toxicology

Discussion groups on Toxicology

Patient Handouts on Toxicology

Directions to Hospitals Treating Toxicology

Risk calculators and risk factors for Toxicology

Healthcare Provider Resources

Symptoms of Toxicology

Causes & Risk Factors for Toxicology

Diagnostic studies for Toxicology

Treatment of Toxicology

Continuing Medical Education (CME)

CME Programs on Toxicology

International

Toxicology en Espanol

Toxicology en Francais

Business

Toxicology in the Marketplace

Patents on Toxicology

Experimental / Informatics

List of terms related to Toxicology

Editor-in-chief: Scott Everett, MD, Pharm D [1]

your textFor Overdosage Contact Poison Control atyour text 1-800-222-1222

Report a side effect to the FDA at MedWatch

Search for drug-drug interactions.

Toxicology (from the Greek words toxicos and logos) is the study of the adverse effects of chemicals on living organisms.[1] It is the study of symptoms, mechanisms, treatments and detection of poisoning, especially the poisoning of people.

History

Mathieu Orfila is considered to be the modern father of toxicology, having given the subject its first formal treatment in 1813 in his Trait des poisons, also called Toxicologie generate.

However, Theophrastus Phillipus Auroleus Bombastus von Hohenheim (1493 - 1541) (also referred to as Paracelsus, from his belief that he was above or beyond the work of Celsus - the Roman physician from the first century) is widely regarded as "the father" of toxicology. He is credited with the classic toxicology soundbite "All things are poison and nothing is without poison; only the dose makes a thing a poison." The original German reads: "Alle Dinge sind Gift und nichts ist ohne Gift; allein die Dosis macht, dass ein Ding kein Gift ist." This is often condensed to "The dose makes the poison".

The term LD50 refers to the dose of a toxic substance that kills 50 percent of a test population (typically rats or other surrogates when the test concerns human toxicity). LD50 estimations in animals are no longer required for regulatory submissions as a part of pre-clinical development package.

Relationship between dose and toxicity

Toxicology studies the relationship between dose and its effects on the living organism. The chief criterion regarding the toxicity of a chemical is the dose, i.e. the amount of exposure to the substance. Almost all substances are toxic under the right conditions as Paracelsus, the father of modern toxicology said, “Sola dosis facit venenum” (only dose makes the poison). Paracelsus, who lived in the 16th century, was the first person to explain the dose-response relationship of toxic substances.

Even a benign substance like water can cause harm in excessive amounts. "Dr. Adrian Cohen was saddened, but not surprised, to hear about the 28-year-old woman who died earlier this month after drinking nearly two gallons of water to try to win a radio station contest." [2]

Toxicity of Metabolites

Many substances regarded as poisons are toxic only indirectly. An example is "wood alcohol," or methanol, which is chemically converted to formaldehyde and formic acid in the liver. It is the formaldehyde and formic acid that cause the toxic effects of methanol exposure. Many drug molecules are made toxic in the liver, a good example being acetaminophen (paracetamol), especially in the presence of alcohol. The genetic variability of certain liver enzymes makes the toxicity of many compounds differ between one individual and the next. Because demands placed on one liver enzyme can induce activity in another, many molecules become toxic only in combination with others. A family of activities that engages many toxicologists includes identifying which liver enzymes convert a molecule into a poison, what are the toxic products of the conversion and under what conditions and in which individuals this conversion takes place.

See also

References

  • Amdur MO, Doull J, Klaassen, CD. 1993. Cassarett and Doull's Toxicology: The Basic Science of Poisons. New York: McGraw-Hill, Inc.
  • Gilbert SG. A Small Dose of Toxicology – The Health Effects of Common Chemicals. CRC Press, Boca Raton, February 2004, p 266. [2]
  • Hodgeson E, Levi PE. 1987. A Textbook of Modern Toxicology. New York: Elsevier Science Publishing Co., Inc.

External links

ar:علم السموم bg:Токсикология ca:Toxicologia cs:Toxikologie da:Toksikologi de:Toxikologie el:Τοξικολογία it:Tossicologia he:טוקסיקולוגיה lt:Toksikologija nl:Toxicologie oc:Toxicologia simple:Toxicology sk:Toxikológia sr:Токсикологија fi:Toksikologia sv:Toxikologi th:พิษวิทยา Template:WH Template:WikiDoc Sources