Analgesics

Question 0

Opioid drugs stimulate opioid receptors within the CNS. What are the three major subtypes of opioid receptors?

Answer 0

Mu, kappa and delta

Question 1

Name three types of pain and explain each.

Answer 1

Acute - sudden short
Chronic - persistent pain, longer than 6 months
Nociceptive - sensory perception of damage to tissue, occurs due to receptor stimulation
Neurogenic - results from injury or disease affecting the nervous system
Psychogenic - pain caused by psychological or emotional behavioural stimulus

Question 2

Which opioid receptor does morphine and most other opioid analgesics exert their analgesic and adverse effects through?

Answer 2

Mu receptor.

Question 3

Name four central effects of analgesia.

Answer 3

• suppression of cough reflex
• suppression of respiratory centre
• sedation/sleep
• euphoria
• hallucinations
• miosis
• nausea, vomiting
• hypotension, bradycardia
• tolerance, dependence

Question 4

Tolerance and dependence are the same thing. True or false.

Answer 4

False.

Question 5

Name three peripheral effects of analgesics.

Answer 5

• decreased intestinal motility (constipation)
• increased smooth muscle tone (sphincter spasm)
• decreased gastric emptying
• suppression of some spinal reflexes
• release of histamine (bronchoconstriction and itching)

Question 6

Opioids are well absorbed orally. True or false.

Answer 6

False. Opioids are not well absorbed orally due to the extensive first pass metabolism in the liver. Opioids generally have 40% availability.

Question 7

If a patient has renal disease, why is important to be aware of opioids effect on the body?

Answer 7

Renal disease extends the half life of opioids, resulting in respiratory depression.

Question 8

Name three examples of opioid analgesics and the different ways they can be administered.

Answer 8

Morphine - oral, IM, SC, IV, epidural
Hydromorphone - IM, IV
Codeine sulfate - oral, IM
Fentanyl - patch, SC, IV
Methadone - oral, IM, IV
Oxycodone - oral, IM, rectal
Tramadol - oral, IM
Pethidine - IV, IM, SC

Question 9

What is codeine metabolised into for most people?

Answer 9

Morphine

Question 10

In the event of a narcotic over-dose, what antidote can be given to reverse the effects, and what is important to consider during the administration of it?

Answer 10

Naloxone.

It is short acting and there is a possibility of rebound and need for repeated dosage.

Question 11

What are the normal dosages for naloxone in adults and neonates?

Answer 11

Adults: 0.4-2mg IV, IM, SC every 2-3 minutes
Neonates: 0.01mg/kg/IV into the umbilical vein or IM, SC, and may be repeated in 2-3 minutes if needed.

Question 12

What is Naltrexone?

Answer 12

• longer acting antagonist given orally
• used to treat alcohol or opioid dependence
• used for rapid opioid detoxification

Question 13

What is the WHO guidelines on analgesic use?

Answer 13

• by the ladder
• by the clock
• by the mouth
• for the individual
• with attention to detail