Analgesics

Question 1

Pain ladder

Answer 1

Non opioids- e.g paracetamol +/- NSAID ( pain 2-5/10) >
Mild opioids- e.g codeine, dihydrocodeine, co-codamol (pain 5-8/10)>
Strong opioids- e.g morphine, diamorphine, fentanyl (pain 8+/10)

Question 2

What are NSAIDS and what pain might they be used for?

Answer 2

Mild-moderate pain, especially MSK as they reduce pain and inflammation- also antipyretics
e.g ibuprofen, diclofenac, aspirin (not paracetamol)

Question 3

Mechanism of action of NSAIDS

Answer 3

Inhibit COX-1 and COX-2 enzymes that produce prostaglandins involved in inflammatory response- reduce this response reduces pain

Question 4

Side effects of NSAIDs

Answer 4

• COX-1 prostaglandins involved in regulation of renal parenchyma, gastric mucosa and myocardium (COX-2 specific used sometimes celecoxib- can cause cardiac problems)
• Gastric ulcers and reduced renal perfusion, other side effects include hypersensitivity reactions and increased bruising/bleeding

Question 5

What are opioids and when are they used?

Answer 5

Visceral pain- emergency department for acute severe pain, childbirt, peri-operative pain control and cancer pain
Mild may be given alone (codeine) or combined (cocodamol- w/paracetamol)

Question 6

Different receptor types and functions

Answer 6

mu, kappa and delta
mu1- analgesia and dependence, inhibits transmission of pain signals ascending nerves of spinal cord
mu2- constipation, drowsiness, nausea, vomiting and RESPIRATORY DEPRESSION

Question 7

What is used to reverse opioid overdose?

Answer 7

Naloxone/ naltrexone

Question 8

Alternative methods of analgesia

Answer 8

Diazepam/ other benzo's for muscle spasm
Tricyclic antidepressants (amitryptiline) or anticonvulsants (carbamazepine)- neuropathic pain
Nerve blocks, joint injections and acupuncture may help