Class notes
Chemical Toxicology
- Course
- Institution
Lecture notes on Chemical Toxicology
[Show more]
Seller
Follow
polinalobacheva
Reviews received
Content preview
Poisoning: an interaction between a foreignchemical (toxin) and a biological system which
results in damage to a living organism
Reasons for poisoning:
- Accidental
- Suisical
- Criminal
Suspected poisoning: biochemical investigation:
- Plasma [urea], [electrolytes] and [creatinine]
- Plasma osmolality and osmolality gap
- Blood gases to asses acid-base status
- Serum [transaminases] and [bilirubin]
- Plasma [glucose]
Poisoning: role of laboratory
- Monitoring of vital functions ex. Measuring
blood gases
- Demonstration of suspected poison in blood
- Monitoring treatment ex. Measuring poison at regular intervals
Paracetamol: Common poisons:
- Analgesic giving relief from fever and pain - Paracetamol
- Common cause of emergency hospital admission due to - Aspirin
its wide availability - Alcohol
- Causes 150 deaths approx. each year in UK - Barbiturates
- Lithium
- Ethylene glycol
- Paraquat
- Carbon monoxide
Paracetamol toxicity:
- Paracetamol rapidly absorbed in upper GIT
- Metabolised in the liver by conjugation with glucuronide (around 40-60%) by UDP-glucuronyl transferase, sulphate
(around 20-30%) by sulfotransferase to form non-toxic metabolites
- A small amount (5-10%) is metabolised by cytochrome P450 to produce N-acetyl-p-benzoquinoneimine (NAPQI)
- NAPQI is normally conjugated with glutathione in liver cells to produce non-toxic mercapturic acid and cysteine
conjugates
- In overdose liver enzymes are saturated and large amounts of NAPQI exhaust glutathione stores
- Free NAPQI can bind to cells causing hepato- and nephrotoxicity
, Paracetamol metabolism:
Paracetamol: toxic dose
- Dose of 15g (adults) and 4g (children) can cause hepatotoxicity
- Such doses deplete liver glutathione by 70%
- In some patients doses of 50%+ are not toxic due to variation in metabolism
- [paracetamol] > 300 mg/L 4 hours after ingestion cause serious liver damage but not < 120 mg/L
Paracetamol poisoning: clinical
Paracetamol poisoning: investigation
1. Plasma [paracetamol]
a. Blood samples taken at least 4 hours post dose
b. Probability of developing hepatotoxicity
c. Based as a guide for patient management
2. Plasma [aminotransferases] / [bilirubin]
3. Plasma [creatinine]
Paracetamol measurement: analytical
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller polinalobacheva. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $13.05. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
81989 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now