Pain

Question 1

Define chronic pain

Answer 1

o Pain lasting for more than 3 months
o Pain lasting after normal healing
o Often no identifiable cause

Question 2

Describe the characteristics of cancer pain

Answer 2

Cancer pain tends to be progressive, and is often a mixture of acute and chronic.

Question 3

Define nociceptive pain

Answer 3

obvious tissue injury illness. Also called physiological or inflammatory pain, has a protective function. Usually described as sharp/dull and well-localised.

Question 4

Define neuropathic pain

Answer 4

Nervous system damage or abnormality, usually without obvious tissue damage. Does not have a protective function. Described as burning or shooting, not well localised. Includes phantom limb pain.

Question 5

What combination of features is pathognomonic for neuropathic pain?

Answer 5

numbness + pain

Question 6

Give four steps in pain physiology

Answer 6

Periphery
Spinal cord
Brain
Modulation

Question 7

Give some pathological mechanisms for neuropathic pain

Answer 7

•	Increased receptor numbers
•	Abnormal sensitisation of nerves
o	Peripheral
o	Central
•	Chemical changes in the dorsal horn
•	Loss of normal inhibitory modulation

Question 8

When is paracetamol used as an analgesic?

Answer 8

Used by itself for mild pain

Used in conjunction with other analgesics for moderate-severe pain

Question 9

Give three examples of non-steroidal anti-inflammatory drugs

Answer 9

Aspirin
Ibuprofen
Diclofenac

Question 10

Give two examples of mild opioid drugs

Answer 10

Codeine

Dihydrocodeine

Question 11

Give three examples of strong opioid drugs

Answer 11

Morphine
Oxycodone
Fentanyl

Question 12

What are the disadvantages of opioids?

Answer 12

Constipation
Respiratory depression in high dose
Misunderstandings about addiction
Controlled drug

Question 13

What is tramadol?

Answer 13

Mixed opiate and 5HT/NA reuptake inhibitor

- weak opioid effect plus inhibitor of serotonin and noradrenaline reuptake

Question 14

Describe the advantages of tramadol

Answer 14

less respiratory depression than morphine
can be used with opioids and simple analgesics
not a controlled drug

Question 15

Describe the disadvantages of tramadol

Answer 15

nausea and vomiting

Question 16

Give two examples of antidepressants that can be used as analgesics

Answer 16

amitriptyline
duloxetine

(triciclic antidepressants TCAs)

Question 17

Why are tricyclic antidepressants useful as analgesics?

Answer 17

they increase descending inhibitory signals

Question 18

Describe the advantages of using TCAs as analgesics

Answer 18

Cheap
Safe in low doses
Good for neuropathic pain
Also treat depression and poor sleep

Question 19

Describe the disadvantages of using TCAs as analgesics

Answer 19

Anticholinergic side effects:

• glaucoma
• urinary retention

Question 20

Give three examples of anticonvulsants that can be used as analgesics

Answer 20

Carbamazepine
Sodium valproate
Gabapentin

Question 21

How to anticonvulsants provide analgesia in neuropathic pain?

Answer 21

reduce abnormal firing of nerves

Question 22

Which two groups of drugs are most effective for neuropathic pain?

Answer 22

Antidepressants (esp. tricyclic antidepressants)

Anticonvulsants

Question 23

Which analgesic treatments work at the peripheral level?

Answer 23

Non-drug treatments: RICE
NSAIDs
Local anaesthetics

Question 24

Which analgesic treatments work at the spinal cord level?

Answer 24

Non-drug treatments: acupuncture, massage, TENS
Local anaesthetics
Opioids
Ketamine

Question 25

Which analgesic treatments work at the brain level?

Answer 25

Psychological therapy
Paracetamol 
Opioids
Amitriptyline (TCAs)
Clonidine