Toxicology Flashcards
(58 cards)
What is the study of the harmful effects of chemical, biological, and physical agents on living organisms called?
Toxicology
Toxicology examines how these agents adversely affect health and living systems.
What is the role of forensics?
The use of science within the legal system
Forensics applies scientific principles to legal investigations.
What does postmortem toxicology involve?
Analyzing a dead body for toxins
The body’s reaction to chemicals can differ after death.
What are poisons?
Anything that harms a living organism
The dose of a substance determines its potential to be a poison.
What are the most frequent occurrences of poisoning?
Most cases result from:
* Social and economic stress or mental disorders
* Illicit substance abuse (minority)
* Substances administered against will
* Unintentional accidents
What is a key responsibility of a toxicologist?
Conduct toxicological analysis
Toxicologists analyze samples to identify poisons and drugs.
What is the National Poisons Information Service (NPIS)?
Advises NHS healthcare professionals on the diagnosis, treatment, and care of poisoned patients.
What is the role of a pathologist in toxicology?
Perform medico-legal autopsies to establish the cause of death
They attend suspicious deaths and estimate time of death.
What are common drugs of abuse?
Legal:
* Alcohol
* Medicines
Illegal:
* Heroin
* Cannabis
What does the Misuse of Drugs Act (1971) state?
It is offensive to:
* Possess a controlled substance unlawfully
* Possess a controlled substance with intent to supply
* Supply or offer to supply a controlled drug
* Allow premises to be used for drug use
What are the categories in the spectrum of drug use?
- Opiates (Morphine, heroin)
- Depressants (alcohol, barbiturates)
- Minor tranquilizers (benzodiazepines)
- Stimulants (cocaine)
- Hallucinogens (LSD)
- Others (cannabis)
What is the goal of toxicological screening techniques?
To confirm and quantify chemical presence
The choice of technique depends on analytical sensitivity and specificity.
What are the steps to toxicological analysis?
- Separation of poison and metabolites from biological material
- Identification
- Confirmation of identity
- Quantification
- Interpretation
What is acute exposure?
Contact with a substance that occurs once or for only a short time (up to 14 days)
It typically leads to immediate effects.
What is chronic exposure?
Contact with a substance that occurs for a year or longer
What are general symptoms of poisoning?
- Neurological
- Respiratory
- Cardiovascular
- Ocular
- Mouth
- GIT
What are the routes of administration/exposure?
- Intravenous
- Dermal
- Inhalation
- Rectal
- Sublingual
- Intraethecal
- Oral
What is the definition of drug metabolism?
The enzyme-catalyzed conversion of a drug into a chemically distinct substance
What is half-life (t1/2) in drug elimination?
Time taken for drug concentration to decline by half
What is the significance of dose-response curves?
They plot % response against log of dosage to determine lethal doses and compare toxicity of substances
What is postmortem redistribution (PMR)?
Artificially elevated drug concentration in heart after death
Drug levels change due to time between death and blood collection.
What factors affect the passage of drugs through cell membranes?
- Water solubility
- Lipid solubility
- Degree of ionization
- Molecular weight
- Active transport
What is the role of analytical methods in toxicology?
To confirm and quantify the presence of chemicals in biological samples
What are some examples of analytical techniques used in toxicology?
- Immunoassays
- Spot colour tests
- TLC
- GC
- HPLC
