Topic 3 - Knowledge and understanding of the drugs

Question 1

What class of drug is Paracetamol?

Answer 1

Non-opioid analgesia

Question 2

What is the drug action of Paracetamol?

Answer 2

Inhibitor

Question 3

What is Paracetamol’s mode of action?

Answer 3

Acts by inhibiting cyclooxygenase (COX) mediated production of prostaglandins.

When tissues are damaged arachidonic acid is released, COX 1+2 enzymes converts arachidonic acid into prostaglandin which produces pain

Paracetamol inhibits the COX 1+2

The antipyretic actions of paracetamol are attributed to direct action on heat-regulating centres in the brain.

Question 4

What class of drug is Diamorphine Hydrochloride?

Answer 4

Opioid

Question 5

What is the drug action of Diamorphine Hydrochloride?

Answer 5

Agonist

Question 6

What is Diamorphine Hydrochloride’s mode of action?

Answer 6

Binds to Mu, Kappa, and Delta receptors (opioid receptors) in the central nervous system. It reduces the conductance of pain signals to the CNS. Diamorphine is a narcotic analgesic which acts primarily on the central nervous system and smooth muscle. It is predominantly a central nervous system depressant, but it has stimulant actions resulting in nausea, vomiting and miosis.

Question 7

What class of drug is Amoxicillin?

Answer 7

Broad spectrum penicillin

Question 8

What is the drug action of Amoxicillin?

Answer 8

Antagonist

Question 9

What is Amoxicillin’s mode of action?

Answer 9

A bactericidal penicillin. Inhibits the synthesis of bacterial cell walls. The bacterial cell is damaged, and the bacteria can no longer survive. It inhibits penicillin binding proteins preventing repair of the bacterial cell walls.

Question 10

What class of drug is Benzylpenicillin?

Answer 10

Beta-lactamase sensitive penicillin

Question 11

What is the drug action of Benzylpenicillin?

Answer 11

Antagonist

Question 12

What is Benzylpenicillin’s mode of action?

Answer 12

Acts by disrupting bacterial cell wall synthesis, leading to cell lysis. It inhibits penicillin binding proteins preventing repair of the bacterial cell walls.

Question 13

What class of drug is Ondansetron?

Answer 13

Serotonin (5ht3) receptor antagonists

Question 14

What is the drug action of Ondansetron?

Answer 14

Antagonist

Question 15

What is Ondansetron’s mode of action?

Answer 15

Acts (centrally) in the Chemoreceptor Trigger Zone. Also acts by selective antagonism of 5-HT3 receptors in both PNS and CNS.

The vagus nerve is triggered by the GI tract to send a message to the vomiting centre of the brain. Ondansetron binds to the serotonin 5HT3 receptor and inhibits serotonin 5HT3 so transmission across the synapse can’t happen

Question 16

What class of drug is Metoclopramide?

Answer 16

Dopamine receptor antagonist

Question 17

What is the drug action of Metoclopramide?

Answer 17

Antagonist

Question 18

What is Metoclopramide’s mode of action?

Answer 18

Exerts a three-fold anti-emetic action: by inhibiting central dopamine receptors, metoclopramide raises the threshold of the chemoreceptor trigger zone and reduces the reaction of the vomiting centre to centrally acting emetics.