Discuss the mechanisms of action of analgesics, their indications and contraindications and different routes of administration

Question 1

By which 6 routes can opioids be administered

Answer 1

1. oral
2. rectal
3. intravenous
4. intramuscular
5. transdermal
6. transmucosal (lozenges)

Question 2

By which routes can non-opioid analgesia be administered?

Answer 2

• oral (via tablets)
• intrathecal infusion (the fluid-filled space between the thin layers of tissue that cover the brain and spinal cord)

Question 3

How do adjuvant analgesics work?

Answer 3

by increasing the therapeutic index of opioids by a dose-sparing effect

Question 4

What are drugs that have primary indications other than pain, but may be analgesic in selected circumstances?

Answer 4

adjuvant analgesics

Question 5

What are 5 conditions that indicate non-opioid analgesics?

Answer 5

1. musculoskeletal pain
2. headache
3. dysmenorrhoea (menstrual cramps)
4. pyrexia
5. chronic disease with inflammation

Question 6

What are 3 contraindications of non-opioid analgesia?

Answer 6

1. patients on warfarin
2. patients with gastric issues
3. patients with respiratory issues

Question 7

How do agonist opioids work?

Answer 7

by agonist action at opioid receptors

Question 8

Baclofen, diazepam (valium) and metaxalone are examples of what type of analgesic?

Answer 8

adjuvant analgesics

Question 9

What are non-opioid analgesics and what are they more suitable for?

Answer 9

painkillers (paracetamol, NSAIDs etc.), more suitable for musculoskeletal conditions

Question 10

What are opioid analgesics?

Answer 10

substances that act on opioid receptors to produce morphine-like effects

Question 11

What are 4 indications of opioid analgesics?

Answer 11

1. moderate to severe pain
2. pre/postoperatively
3. cancer
4. myocardial infarction

Question 12

What are the three types of analgesic?

Answer 12

1. non-opioid analgesics
2. opioid analgesics
3. adjuvant analgesics

Question 13

What are some examples of opioid analgesics? (6)

Answer 13

1. morphine
2. buprenorphine
3. diamorphine hydrochloride (heroin)
4. fentanyl
5. tramadol hydrochloride
6. codeine phosphate
   7.

Question 14

When are adjuvant analgesics contraindicated?

Answer 14

• substance abuse
• aberrant behaviour
• organ failure
• allergy

Question 15

What is the mechanism of action of non-opioid analgesics?

Answer 15

(cox)-3 is inhibited

Question 16

What are the 4 classes of adjuvant analgesics?

Answer 16

1. multipurpose
2. neuropathic pain
3. musculoskeletal pain
4. cancer pain

Question 17

What indicates use of adjuvant analgesics?

Answer 17

management of a medical condition with secondary analgesic effects

Question 18

What are 3 contraindications to using opioid analgesia?

Answer 18

1. acute respiratory depression
2. acute alcohol intoxication
3. head injuries prior to neurological assessment

Question 19

What are paracetamol, naproxen, nefopam hydrochloride and ibuprofen all examples of?

Answer 19

Non-opioid analgesics