W9 - Toxins

Question 1

What is toxicology

Answer 1

the study of the effect of poisons on the function of living systems

Question 2

What are some examples of agents that can be toxic to the human body

Answer 2

drugs
paracetamol
penicillin
thalidomide
novichok
sarin

Question 3

What was Paracelsus’s statement on toxicity

Answer 3

all things are poison and nothing is without poison only the dose permits something not to be poisonous

Question 4

What did we learn from paracelsus’s statement

Answer 4

the dose makes the poison

Question 5

describe the range between the therapeutic effect and the toxic effect

Answer 5

Every drug has a therapeutic effect and a toxic effect, in an ideal drug the toxic effect limit will be much higher than the therapeutic effect. So that a dose can be increased to have a higher therapeutic effect before it would become toxic

Question 6

What is an ADR

Answer 6

Adverse Drug Reactions. They are noxious or unintended responses occurring at therapeutic doses

Question 7

What are the two types of ADR

Answer 7

Type A (Augmented)

Type B (Bizzarre)

Question 8

What are the effects of an augmented ADR

Answer 8

related to known pharmacology but undesirable

common

dose related

predictable

Question 9

what is an example of an augmented ADR

Answer 9

Hemorrhage with anticoagulants

Question 10

What are the effects of a bizarre ADR

Answer 10

unrelated to known pharmacology

Rare

Unpredictable

Often idiosyncratic

Question 11

What is an example of a bizarre ADR

Answer 11

anaphylaxis with penicilin

Question 12

what are the 4 part of toxicokinetics

Think pharmacokinetics

Answer 12

ADME

Absorption
Distribution
Metabolism
Excretion

Question 13

What are two ways in which toxic materials are absorbed

Answer 13

ingestion

inhalatin

Question 14

what are two metabolic processes that can be found in toxicokinetics

Answer 14

Detoxification

Toxification

Question 15

what is detoxification

Answer 15

compound rendered less toxic

Question 16

what is toxification

Answer 16

relatively inert compound converted into toxin

Question 17

What are the 4 types of basic clinical syndromes (gell and combes)

Answer 17

Type 1 - Hypersensitivity reaction

Type 2 - Antibody mediated cytotoxic hypersensitivity reaction

Type 3 - Immune complex mediated hypersensitivity reaction

Type 4 - Delayed type hypersensitivity

Question 18

Describe the mechanism of a hypersensitivity reaction (histamine)

Answer 18

Hapten binds onto a low molecular weight allergen such as bee venom peanut oil or penicilin, this forms the immunogenic conjugate. This then binds to an IgE site on a mast cell which triggers the release of histamine.

Question 19

What is the response of a hypersensitivity reaction

Answer 19

Bronchoconstriction
Vasodilation
Inflammation

Question 20

What is a type one clinical syndrome treated with

Answer 20

adrenaline

Question 21

Describe the mechanism of a type 2 hypersensitivity reaction

Answer 21

• Toxic antigen binds to red blood cell, an IgG then binds to the red blood cell which then allows a T cell to bind and cause a mediated cell lysis.

Question 22

What can a type 2 hypersensitivity reaction cause the lysis of

Answer 22

red blood cells
neutrophile
platelets

Question 23

what is hameolytic anemia

Answer 23

lysis of red blood cells

Question 24

what is agranulocytosis

Answer 24

lysis of neutrophiles

Question 25

wht is thrombocytopenia

Answer 25

lysis of platelets

Question 26

What are the 4 types of molecular drug / toxin target

Answer 26

receptor enzyme carriers othere e.g. protein in vesicle release

Question 27

what are the 4 types of receptor

Answer 27

ligang gated ion channel gpcrs enzyme linked receptors nuclear receptors

Question 28

what do animal toxins block

Answer 28

ion conduction

Question 29

what do dendrotoxins block

Answer 29

voltage gated K+ channels

Question 30

What channel is an important toxin target

Answer 30

Ca2+

Question 31

what does tetrodotoxin act on

Answer 31

Na+

Question 32

What effects can be affected by the release of cellular effects

Answer 32

increased secretion e.g. eyes watering convulsions bradycardia hypotension bronchoconstriction respiratory depression

Question 33

What is ACHE

Answer 33

acetyl choline esterase

Question 34

what happens if ache is inhibited

Answer 34

acetyl choline is not broken down safely and that can lead to deadly consequences

Question 35

describe the effect of sarin of the the acetylcholinesterase active site

Answer 35

the molecule binds onto the serine molecule preventing aceytlcholine from being broken down as the active site has a competitive inhibitor blocking it

Question 36

What role do oxines have in helping the body against sarin gas attacks

Answer 36

they are strong nucleophiles which take the molecule that has binded onto the serine particle and seperates it which in turn reactivates acetylcholinesterase

Question 37

why is carbon monixide toxic

Answer 37

displaces oxygen from hameoglobin

Question 38

Why is cyanide toxic

Answer 38

cyanide inhibits mitochondrial cytochrome c oxidase to prevent cellular respiration

Question 39

what 2 organs are most susceptible to toxin damage

Answer 39

liver | kidney

Question 40

what are the 3 types of hepatoxicity

Answer 40

hepatic necrosis hepatic inflammation chronic liver damage

Question 41

what is hepatic necrosis

Answer 41

paracetamol poisoning

Question 42

what is hepatic inflammation

Answer 42

hepatitis is when halothane can covalently bind to liver proteins to trigger an autoimmune reaction

Question 43

what is chronic liver damage

Answer 43

long term ethanol abuse causes cellular toxicity and inflammation and malnutrition as ethanol becomes a food source