PHARM Y1 S1: Envenoming

Question 1

venomous vs poisonous

Answer 1

• venomous: if you get bitten > has some kind of stinger, fangs/spine
• poisonous: if you ingest something

Question 2

snake neurotoxins

Answer 2

• presynaptic (B-neurotoxins): slow onset, largely irreversible, block release
• postsynaptic (a-neurotoxins): “curare-like”, rapid onset, largely reversible, block NMJ

Question 3

snake haemotoxin

Answer 3

• procoagulant activity > causes excessive clotting > run out of clotting factors > blood can’t clot
• also some anticoagulant activity but less common

Question 4

first aid for venom

Answer 4

• pressure bandage over the top + immobilisation of limbs to stop venom from moving
• allows time to get to hospital to give antivenom

Question 5

antivenom

Answer 5

• purified antibodies obtained from animals immunised against the venom
• can sometimes have anaphylaxis due to mass pumping in of foreign proteins
• can’t reverse damage already done

Question 6

antivenom that can cure many different bites

Answer 6

polyvalent

Question 7

lethality

Answer 7

• amount of venom required to kill 50% of mice that are injected with it (LD50)