Opioids

Question 1

Examples of opiates

Answer 1

Codeine
Morphine
Heroin

Question 2

How can you get morphine from codeine?

Answer 2

Codeine can be metabolised to morphine by CYP2D6

Question 3

Examples of therapeutic opioids

Answer 3

Codeine
Fentanyl
Morphine

Question 4

What are the uses of therapeutic opioids

Answer 4

• Analgesia
• Antitussive (cough suppression)
• anti-diarrhoea
• anaesthetic
• palliation

Question 5

Outline the onset + duration of fentanyl compared to morphine

Answer 5

• fentanyl: fast onset + short duration
• morphine: slow onset + long duration

Question 6

What are the adverse drug reactions of therapeutic opioids

Answer 6

• constipation
• drowsiness
• dysphoria
• flushing + headache
• hyperhidrosis
• miosis
• nausea
• respiratory depression
• itching
• urinary retention

Question 7

What are contraindications of therapeutic opioids?

Answer 7

• head injury or raised ICP
• depression
• asthmatics
• pregnancy
• paralytic ileus

Question 8

What are important drug drug reactions of therapeutic opioids?

Answer 8

• CNS depressants e.g. AEDs + benzos
• other opioid containing drugs
• drugs that reduce gut motility
• CYP450 inhibitors

Question 9

What drug is used to opioid overdose?
How does it work?

Answer 9

Naloxone
Competitive opioid receptor antagonist

Question 10

What opioids are used in used disorder?

Answer 10

Buprenorphine
Methadone

Question 11

Signs of opioid overdose

Answer 11

• Pinpoint pupils
• blue lips + fingertips
• bradycardia, weak pulse or hypotension
• slow, irregular breathing
• not waking up or responding to voice/touch

Question 12

What is the mechanism of action of buprenorphine in use disorder?

Answer 12

• Partial agonist of µ receptors
• activate them but to a lower extent than full agonists
• produces enough opioid effect to alleviate withdrawal symptoms but with less euphoria than full agonsits
• Relatively long action

Question 13

What is the mechanism of action of methadone in use disorder?

Answer 13

• full agonsits for µ receptors > alleviates withdrawal symptoms of opioid dependence
• but more lipophilic than morphine so longer duration of action

Question 14

What opiate is a metabolite of codeine?

Answer 14

Morphine

Question 15

What stimulates people to keep taking opioids beyond analgesic benefits?

Answer 15

• Release of dopamine > euphoric feeling
• addiction + dependence

Question 16

How do opioids produce their analgesic effect?
(Mechanism of action)

Answer 16

• bind to µ receptors
• inhibits pain signal transmission by blocking neurotransmitter release
• reducing perception of pain > analgesic affect

Question 17

Order fentanyl, buprenorphine, morphine + codeine in terms of protency from most to least

Answer 17

• fentanyl
• buprenorphine
• morphine
• codeine

Question 18

Why may additional doses of naloxone need to be administered after a period of time

Answer 18

• Rapid distribution - duration only 30-60
• Antagonistic affects may wear off before opioid has been cleared

Question 19

What is opioid dependence?

Answer 19

Need to keep taking opioids at higher doses to feel normal (not even to have analgesic or euphoric feeling)

Question 20

What are classes of drugs assigned based on?
What is the scale

Answer 20

Harmfulness attributed to drug when it is misused
A-C

Question 21

Describe drug schedules

Answer 21

• dictates how drug is produced, stored, how prescribed + what records need to be kept
• schedule 1: drugs not used mediciniallly
• schedule 2-5: decreasing controls + requirements
• lower the schedule, the lower potential for abuse + dependence

Question 22

What class + schedule do opioids have?

Answer 22

Class A-C
Schedule 2,3+5

Question 23

What is drug tolerance?

Answer 23

Higher dose of drug is needed to elicit the same response

Question 24

Define opiate
Examples

Answer 24

Natural opioids
heroin, codeine, morphine

Question 25

Where do opioids inhibit pain?

Answer 25

In the dorsal horn of the spinal cord