Analgesic Drugs

Question 1

how do NSAIDs stop pain?

Answer 1

they decrease nociceptor stimulation in inflammation

Question 2

how do opioids stop pain?

Answer 2

suppress transmission of nociceptive signals in the DORSAL horn of the spinal cord AND
activate descending inhibitory controls

Question 3

how do anti-epileptics stop pain?

Answer 3

target ion channels that have been upregulated in nerve damage

Question 4

difference between opiate and opioid?

Answer 4

an opiate is a substance attracted from opium ONLY whereas an opioid is any agent that acts upon opioid receptors

Question 5

what can stop pain from ascending the spinal cord?

Answer 5

inhibitory interneurones

Question 6

what fibres excite inhibitory interneurones?

Answer 6

A-beta fibres

low threshold mechanoreceptors

Question 7

what fibres suppress inhibitory interneurones (thus allowing nociceptive input to ascend the spinal cord and cause pain)?

Answer 7

C fibres

A-delta fibres

Question 8

all primary sensory afferents are excitatory T or F

Answer 8

T

Question 9

where is nociceptive input inhibited by fibres?

Answer 9

dorsal horn of the spinal cord

Question 10

what parts of the brain are involved in pain perception and emotion?

Answer 10

cortex
amygdala
thalamus
hypothalamus

then project input to the BRAINSTEM

Question 11

the periaqueductal grey is located where in the brainstem?

Answer 11

midbrain

Question 12

what does the periaqueductal grey do?

Answer 12

causes descending inhibition which presents nociceptive input reaching the thalamus

Question 13

opioids _regulate the activity of the preriaqueductal grey

Answer 13

up

Question 14

what part of the brainstem inhibits noradrenaline?

Answer 14

locus coeruleus

Question 15

what part of the brainstem inhibits 5-HT and thus serotonin?

Answer 15

nucleus raphe magnus

Question 16

all opioids act on what receptors?

Answer 16

GPCRs

Question 17

what G-proteins do opioids act on?

Answer 17

Gi

Go

Question 18

opioids ___ voltage-activated Ca channel opening; why?

Answer 18

inhibit

stops glutamate release thus dampening down nerve conduction

Question 19

opioids ___ K+ channel opening; why?

Answer 19

upregulate

will cause more hyperpolarisation thus will dampen down the excitatory response

Question 20

what type of opioid receptor is responsible for most of the analgesic action of opioids?

Answer 20

μ receptors

Question 21

resp side effects of opioids?

Answer 21

apnoea

bronchospasm in asthmatics

Question 22

GI side effects of opioids?

Answer 22

N+V
constipation
inc intrabiliary pressure

Question 23

morphine is metabolised in the liver by what process?

Answer 23

glucorinidation

Question 24

diamorphine has a __ onset of action

Answer 24

fast

Question 25

pethidine is mainly used for what kind of pain?

Answer 25

pain in labour

Question 26

MoA of tramadol

Answer 26

μ-receptor agonist

Question 27

tramadol should be avoided in what patients?

Answer 27

epileptic

Question 28

methadone is given via what route?

Answer 28

oral

Question 29

what is the main opioid antagonist used to counteract opioid toxicity?

Answer 29

naloxone IV

Question 30

morphine should be carefully used in what patients?

Answer 30

addicts
asthmatics
patients with kidney disease

Question 31

COX enzymes catabolise what?

Answer 31

arachidonic acid into endoperoxides (to make prostaglandins)

Question 32

diamorphine is another word for what compound?

Answer 32

heroin

Question 33

in order to suppress production of prostaglandins in the dorsal horn of the spinal cord, NSAIDs must do what first?

Answer 33

cross the BBB