Analgesia in Oral Surgery

Question 1

what drugs can we prescribe for pain in dentistry

Answer 1

aspirin
ibuprofen
diclofenac
dihydrocodeine
carbamazepine
paracetamol

Question 2

what is the arachidonic pathway of pain

Answer 2

trauma and infection lead to breakdown of membrane phospholipids producing arachidonic acid
this can be broken down to form prostaglandins
these sensitise tissues to other inflammatory products which results in pain

Question 3

what is the action of prostaglandins

Answer 3

sensitise tissues to other inflammatory products such as leukotrienes

Question 4

what are the properties of aspirin

Answer 4

analgesic
antipyretic
antiinflammatory
metabolic

Question 5

what is the mechanism of action of aspirin

Answer 5

inhibits COX1 and COX2 to reduce production of prostaglandins

Question 6

what does COX1 inhibition do

Answer 6

reduce platelet aggregation

Question 7

what is the analgesic action of aspirin

Answer 7

peripheral action predominates
results from inhibition of prostaglandin synthesis in inflamed tissues

Question 8

what is the antipyretic properties of aspirin

Answer 8

prevents the temperature raising effects of IL1 and rise in brain prostaglandin levels so reduces elevated temperature in fever

Question 9

what is the antiinflammatory action of aspirin

Answer 9

as they inhibit production of prostaglandins (which are vasodilators) they can reduce redness and swelling

Question 10

what are the adverse effects of aspirin

Answer 10

GIT problems
hypersensitive
overdose - tinnitus, metabolic acidosis
aspirin burns - mucosal

Question 11

how does aspirin cause GIT problems

Answer 11

as prostaglandins inhibit gastric acid secretion and increase blood flow through gastric mucosa and help production of mucin cells
aspirin stops this by inhibiting prostaglandin secretion

Question 12

what hypersensitivity reactions can occur due to aspirin

Answer 12

acute bronchospasm/asthma attacks
skin rashes/urticaria

Question 13

what would overdose of aspirin present as

Answer 13

hyperventilation
tinnitus, deafness
vasodilation and sweating
metabolic acidosis
coma

Question 14

how does aspirin cause mucosal burns

Answer 14

due to salicylic acid

Question 15

how do you prevent mucosal aspirin burns

Answer 15

make sure aspirin is taken with water

Question 16

what are the groups to avoid when prescribing aspirin

Answer 16

peptic ulcers
epigastric pain
bleeding abnormalities
anticoagulants
pregnant/breast feeding
patients on steroids
renal/hepatic impairment
under 16s
asthma
allergies to other NSAIDs
taking other NSAIDs
elderly

Question 17

why should people on anticoagulants avoid aspirin

Answer 17

it enhances warfarin and other coumarin anticoagulants as it displaces warfarin from binding sites of plasma proteins and increases free warfarin

Question 18

why should pregnant people not take aspirin

Answer 18

increased risk of haemorrhage
increased risk of jaundice in baby
prolong/delay labour

Question 19

why should patients on steroids avoid taking aspirin

Answer 19

25% of steroid patients will develop peptic ulcer
aspirin can result in perforation of the ulcer

Question 20

where is aspirin metabolised and excreted

Answer 20

metabolised in liver
excreted in kidney

Question 21

with regards to the kidneys, what might inhibition of renal prostaglandin result in

Answer 21

sodium retention
reduced renal blood flow
renal failure

Question 22

what is reye’s syndrome

Answer 22

fatty degenerative process in liver causing profound swelling in the brain

Question 23

when is aspirin completely contraindicated

Answer 23

children and adolescents under 16
previous or active peptic ulceration
haemophilia
hypersensitivity to aspirin or any other NSAID

Question 24

what is the prescription for aspirin

Answer 24

aspirin dispersible tablets 300mg
two tablets four times daily, preferably after food for five days

Question 25

what is the prescription for ibuprofen

Answer 25

ibuprofen tablets 400mg 20 tablets take one tablet four times daily, preferably after food for five days

Question 26

what is the max dose of ibuprofen

Answer 26

2.4g

Question 27

when do you take caution when prescribing ibuprofen

Answer 27

previous or active peptic ulceration elderly pregnancy and lactation renal, cardiac or hepatic impairment history of hypersensitivity to aspirin and NSAIDs ashtma patient taking other NSAIDs patient on long term systemic steroids

Question 28

what are the side effects of ibuprofen

Answer 28

GIT discomfort, bleeding and ulceration hypersensitivity reactions

Question 29

name some potential drug interactions for ibuprofen

Answer 29

ACE inhibitors beta blockers antibiotics anticoagulants

Question 30

what are the symptoms of an ibuprofen overdose

Answer 30

nausea vomiting tinnitus

Question 31

what do you do if more than 400mg/kg has been ingested within preceding hour

Answer 31

activated charcoal followed by symptomatic measures

Question 32

what are the affects of paracetamol

Answer 32

analgesic antipyretic little or no antiinflammatory action less irritable to GIT no effects on bleeding time does not interact with warfarin suitable for children

Question 33

what is the mode of action of paracetamol

Answer 33

inhibit positive feedback of hydroperoxides which inhibits COX

Question 34

what does the mode of action of paracetamol result in

Answer 34

analgesia antipyretic action no reduction in peripheral inflammation

Question 35

what is the main site of action of paracetamol

Answer 35

thalamus

Question 36

why does paracetamol not have an affect on gastric mucosa

Answer 36

it does not appear to have much effect on peripheral prostaglandins

Question 37

what are the cautions when prescribing paracetamol

Answer 37

hepatic impairment renal impairment alcohol dependence

Question 38

what are paracetamol side effects

Answer 38

rashes blood disorders hypotension reported on infusion liver damage following overdose

Question 39

what drug interactions does paracetamol have

Answer 39

anticoagulants cytotoxics domperidone lipid regulating drugs metoclopramide

Question 40

what is the prescription for paracetamol

Answer 40

paracetamol tablets 500mg 40 tablets 2 tablets four times daily for five days

Question 41

what is the max dose of paracetamol

Answer 41

4g daily (8 tablets)

Question 42

how much paracetamol would cause an overdose

Answer 42

150mg/kg

Question 43

where does opioid analgesia work

Answer 43

in spinal cord in dorsal horn pathways

Question 44

how do opioids work

Answer 44

via specific receptors which are associated with neuronal pathways that transmit pain to CNS

Question 45

what is the dependence issue with opioids

Answer 45

withdrawal will lead to psychological cravings and patient will be physically ill

Question 46

what is the tolerance issue with opioids

Answer 46

dose of drug needs to be progressively increased

Question 47

what are the effects of opioids on smooth muscle

Answer 47

constipation urinary and bile retention

Question 48

what are the cns effects of opioids

Answer 48

depresses: - pain centre - higher centres - respiratory centre - cough centre

Question 49

what are the most common side effects of opioids

Answer 49

nausea vomiting drowsiness sometimes produce respiratory depression and hypotension

Question 50

what are the cautions with opioids

Answer 50

hypotension hypothyroidism asthma decreased respiratory reserve pregnancy/breastfeeding may cause coma in hepatic impairment renal impairment elderly convulsive disorders dependence

Question 51

what are the contraindications to opioids

Answer 51

acute respiratory depression acute alcoholism raised intracranial pressure

Question 52

what is the only codeine on the dental list

Answer 52

dihydrocodeine

Question 53

what is the dose of dihydrocodeine

Answer 53

30mg every four to six hours as necessary

Question 54

what are the side effects of dihydrocodeine

Answer 54

nausea/vomiting constipation drowsiness

Question 55

what are the interactions of dihydrocodeine

Answer 55

antidepressants dopaminergics

Question 56

when would you never prescribe dihydrocodeine

Answer 56

raised intracranial pressure/suspected head injury

Question 57

when would you use dihydrocodeine

Answer 57

moderate to severe pain but it is of little value for dental pain

Question 58

what is the antidote for opioid overdose

Answer 58

naloxone

Question 59

what drug is used for neuropathic pain

Answer 59

carbamazepine

Question 60

what are the clinical features of trigeminal neuralgia

Answer 60

severe spasms of pain usually unilateral older age group trigger spot identified females more than males periods of remission recurrences often greater severity