Toxicology Flashcards
(18 cards)
What are the three sites of absorption?
Skin
Lungs
GI tract
Define carcinogenesis
Uncontrollable cell proliferation
Define teratogenesis
Foetal or embryonic development
Define immunotoxicology
Hypersensitivity and allergy
Who are high risk groups?
Children
Elderly
Pregnant women
Sick
Malnourished
Explain the process of anti freeze poisoning
Anti freeze is either ethylene glycol or methanol both broken down by alcohol dehydrogenase.
Methanol becomes formaldehyde which causes is blindness which is then broken down by aldehyde dehydrogenase to form formic acid which causes metabolic acidosis
Ethylene glycol becomes oxalic acid which causes acidosis and crystals in brain and kidney
What is the treatment of anti freeze poisoning?
Giving oral ethanol
Ethanol is a preferred alcohol dehydrogenase substrate.
Out competes anti freeze
Describe mild alcohol poisoning
Depression of cns
Visual impairment
Decreased muscle coordination
Slow reaction time
Respiratory depression
Hypotension hypothermia hypoglycaemia
Unconsciousness and death
What does a lethal dose of alcohol cause?
Cirrhosis
Describe cyanide poisoning
Respiratory chain inhibition in mitochondria
HCN binds to cytochrome aa3
ATP production drastically reduced
Brain/heart affected the most
What is the treatment of cyanide poisoning?
Thiosulphate + CN —> thiocyanate + SO4
Thiocyanate less toxic and excreted in urine.
How does CO cause death?
Has higher affinity for Hb than O2
Death through hypoxia and ischemic damage
How to treat CO poisoning?
Remove to fresh air
Hospital treatment with high flow O2
Hyperbaric O2
What does reach stand for?
Registration
Evaluation
Authorisation
Chemicals
What is paracetamol metabolised by?
Metabolised by conjugation.
Sulphate
Glucuronic acid
What happens during paracetamol overdose?
Conjugation pathways saturated
Conjugation moieties depleted
More emphasis on oxidation
Liver glutathione depletion
What happens when a toxic dose of paracetamol is taken?
Lipid peroxidation
Gsh depletion
Stimulation of ca2+ activated degradative enzymes
Increased membrane permeability
Oxidative stress
All cause cell death
