Pain and analgesics 3 (analgesic drugs)

Question 1

What general process is boosted by analgesic drugs?

Answer 1

Descending inhibition of nociception

Question 2

Which processes are inhibited by analgesic drugs?

Answer 2

Central sensitisation and peripheral sensitisation

Question 3

How do nonsteroidal anti-inflammatories cause analgesia?

Answer 3

They inhibit the process of peripheral sensitisation

Question 4

How do opioid analgesics cause analgesia?

Answer 4

Boost the descending inhibition of nociception

Question 5

What do opioids mimic in order to have their analgesic effect?

Answer 5

Endogenous opioid agonists

Question 6

Where do opioids act?

Answer 6

On opioid receptors

Question 7

Examples of opioids?

Answer 7

Morphine, heroin, fentanyl, codeine

Question 8

What are some low potency opioids?

Answer 8

Codeine, pethidine, buprenorphine

Question 9

What is etorphine used for?

Answer 9

Veterinary medicine–> large animals

Question 10

What is naloxone?

Answer 10

An opioid receptor antagonist

Question 11

How does naloxone work?

Answer 11

It is a opioid mew delta and kappa antagonist

Question 12

Which drugs are used for mild pain?

Answer 12

NSAIDs (nonsteroidal anti inflammatories)

Question 13

Examples of NSAIDs?

Answer 13

Aspirin, ibuprofen

Question 14

What are opioids given to people in moderate pain?

Answer 14

Codeine, buprenorphine

Question 15

What are some opioids given to people in severe pain?

Answer 15

Morphine, fentanyl

Question 16

How do the opioid receptors on free nerve endings have an inhibitory effect?

Answer 16

When an agonist binds K+ channels open and allow K+ to leave the cell–> hyperpolarisation

Question 17

Where are supraspinal opioid receptors?

Answer 17

PAG and locus coeruleus

Question 18

Which type of opioid receptor do most analgesics target?

Answer 18

Mu

Question 19

Which opioid receptor do morphine, methadone and fentanyl target?

Answer 19

Mu

Question 20

Can morphine and fentanyl also target delta and kappa receptors?

Answer 20

Yes

Question 21

Main issue with mu opioid receptors?

Answer 21

When agonised they can cause respiratory depression

Question 22

Benefit of targeting delta and kappa receptors over mu?

Answer 22

They do not cause respiratory depression when agonsied

Question 23

Mood effect of mu receptor being agonised?

Answer 23

Euphoria

Question 24

Mood effect of kappa receptor being agonised?

Answer 24

dysphoria

Question 24

Effect of kappa receptors being agonised on bodily waste?

Answer 24

Diuresis

Question 25

Mood effect of delta receptor being agonised?

Answer 25

none

Question 26

Main issue with agonising delta opioid receptors?

Answer 26

Proconvulsant

Question 27

Undesirable effects of mu opioid receptor?

Answer 27

Constipation, sedation, nausea and vomiting, itching

Question 28

Why does mu opioid receptor agonists being activated cause constipation?

Answer 28

They activate mu opioid receptors in the gut

Question 29

Why can methylnaltrexone be taken to prevent constipation but not the analgesic effect of opioids targeting mu receptors?

Answer 29

It cant cross the blood brain barrier meaning it can block the opioid receptors in the gut (so no constipation) but cant access the locus coeruleus or PAG

Question 30

What is psychological dependance?

Answer 30

Addiction

Question 31

What is physical dependance?

Answer 31

When someone stops taking a drug and they have physical withdrawal symptoms

Question 32

Result of increasing potency of mu receptor agonist on side effects?

Answer 32

They increase

Question 33

What changes need to be made to the dose of a drug if continued use occurs?

Answer 33

The dosage will need to increase

Question 34

What is the main active ingredient in an opium poppy?

Answer 34

morphine

Question 35

Main structural difference between morphine and heroin?

Answer 35

Heroin has two acetyl groups where morphine has two OH groups

Question 36

What benefit does having two acetyl groups instead of two OH groups give heroin over morphine?

Answer 36

It crosses the blood brain barrier more easily

Question 37

What drawback is there of having two acetyl groups instead of two OH in heroin compared to morphine?

Answer 37

Makes heroin completely ineffective against the mu opioid receptor (heroin itself is not an opioid receptor agonist)

Question 38

Why does heroin not having the correct structure to be a mu opioid receptor agonist not really matter?

Answer 38

There are many enzymes in the brain which can cleave the acetyl groups off

Question 39

What is a pro-drug?

Answer 39

A drug that has to be metabolised in order to be its active ingredient

Question 40

Which analgesics are taken in pill form?

Answer 40

Morphine, codeine

Question 41

Which analgesics are taken via intravenous injections?

Answer 41

morphine, diamorphine, fentalyl