Analgesics In Primary Care

Question 1

Name the 4 types of analgesics for mild to moderate pain relief

Answer 1

Paracetamol

NSAIDs
- non-selective e.g. ibuprofen, naproxen
- selective e.g. celecoxib

Aspirin

Weak opioids e.g. codeine, dihydrocodeine and tramadol

Question 2

Mechanism of action of NSAIDs

Answer 2

Inhibit COX-1 and 2 enzymes which decreases prostanoid synthesis. Resulting in antipyretic, analgesic and anti-inflammatory properties

Non-selective act on both COX-1 and 2

Selective act on mainly COX-2

Question 3

Mechanism of action of weak opioids

Answer 3

Bind to opioid receptors in CNS and GI tract which decreases pain perception.

Question 3

Mechanism of action of Aspirin

Answer 3

Essentially an NSAID, very selective for COX-1. COX-1 forms platelet aggregating agent thromboxane. If COX-1 is decreased = less platelet aggregation. This is Irreversible

Question 3

Mechanism of action of paracetamol

Answer 3

Inhibits COX enzymes within the CNS, but not fully understood

Question 4

When is paracetamol and ibruprofen alone indicated

Answer 4

In children under 16

Question 5

Name the 5 step approach to pain relief

Answer 5

1 - paracetamol
2 - ibuprofen substituted, if unsuitable use a weak opioid
3 - paracetamol added to ibuprofen or weak opioid
4 - paracetamol and alternative NSAID e.g. naproxen
4 - weak opioid and NSAID