Biology/Why is it that an overdose of paracetamol hurts?
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Question
Why is it that an overdose of paracetamol hurts while an overdose of heroin doesn't when they are both painkillers?
Dear Kristian,
Paracetamol (acetominophen) has completely different chemical composition from heroin, an opium derivative. The former, in overdose, causes acute liver failure, which is very unpleasant due to the accumulation of toxic products in the body. Heroin and other opioids suppress the nervous system, dulling pain receptors. The mode of action in the painkilling is entirely different from acetominophen, which inhibits the inflammatory response.
You can read about the precise mechanism of action of paracetamol here:
http://en.wikipedia.org/wiki/Paracetamol#Mechanism_of_action
and heroin here:
http://en.wikipedia.org/wiki/Heroin#Pharmacology
to compare.
Dana
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Answers by Expert:
Dana Krempels, Ph.D.
Expertise
I can answer biology-related questions in the areas of evolution, zoology, botany, genetics, and ecology. But I don't answer homework questions or provide ideas for your science fair projects. So students please do your learning the right way by reading your text assignments and studying!
Experience
At the University of Miami, I teach Evolution and Biodiversity, Botany, Zoology, Genetics, Ecology, and a variety of seminars (e.g., the Biology and Evolution of Human Gender Roles).
Education/Credentials
I have a B.S. in Biology and an A.B. in English from the University of Southern California (1980).
I earned my Ph.D. in Biology in the area of evolutionary biology/visual physiology from the University of Miami in 1989.
Past/Present Clients
I am currently an "expert" in both the "Rabbits" and "Wild Animals" categories.
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