drugs for pain

Question 1

what are drugs for pain called

Answer 1

analgesics

Question 2

types of analgesics?

Answer 2

simple - paracetamol
opioid analgesics

Question 3

which specialised nerve endings sense pain

Answer 3

nociceptors

Question 4

pain pathway?

Answer 4

nociceptor -> first order neurone -> dorsal horn in spinal cord -> second order neurone -> ascends in spinothalamic tract -> third order neurone in thalamus in brain -> primary somatosensory cortex

Question 5

4 classes of pain

Answer 5

nociceptive (somatic and visceral)
inflammatory pain
neuropathic pain

Question 6

COX?

Answer 6

cyclo-oxygenase - enzyme in brain

Question 7

half-life of paracetamol

Answer 7

2 hours

Question 8

overdose of paracetamol

Answer 8

hepatotoxicity - liver function impairment

Question 9

max daily dose paracetamol

Answer 9

4g

Question 10

opioid vs opiate

Answer 10

opioid- natural/synthetic
opiate - natural

Question 11

strong opioids

Answer 11

morphine, diamorphine, oxycodone, fentanyl, pethidine, methadone, tramadol

Question 12

weak opiods

Answer 12

codeine
dihydrocodeine

Question 13

opioids mechanism of action

Answer 13

act at G-protein coupled receptors
pre-synaptic - inhibit calcium channels on nociceptive afferent (inhibits neurotransmitters release)
postsynaptic - open inward potassium channels hyperpolarising cell membranes

Question 14

opioids pharmacokinetics

Answer 14

extensive first-pass metabolism in liver
2-3 hr half life
peak conc reached after 1-2 hrs

Question 15

clinical effects of opioids

Answer 15

pain relief, Veno dilation for pulmonary oedema

Question 16

opioids administration

Answer 16

by mouth, immediate release or modified release tablets
intravenous injection, or subcutaneous for palliative care
transdermal

Question 17

adverse effects of opioids

Answer 17

confusion/drowsiness/dizziness
euphoric mood, hallucination, miosis (constricted pupils), respiratory and cough depression
urinary retention
flushing, hypotension

Question 18

local anaesthetics 3 examples

Answer 18

lidocaine, prilocaine, bupivacaine

Question 19

local anaesthetics mechanism of action

Answer 19

block sodium channels to prevent membrane deoplarisation

Question 20

administration

Answer 20

topical application to skin and mucosa
subcutaneous injection
deep injection

Question 21

adverse effects of local anasthetic

Answer 21

nervous and cardiovascular system depression

Question 22

monitoring and follow up for local anaesthetics

Answer 22

care must be taken to spot signs of inadvertent systemic absorption

Question 23

drugs for neuropathic pain

Answer 23

carbamazepine, amitriptyline

Question 24

drugs for migraines

Answer 24

sumatriptan

Question 25

drugs for myocardial ischaemia

Answer 25

glyceryl trinitrate

Question 26

drugs for gout

Answer 26

colchicine