Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

BDS3 Oral Surgery > Analgesia > Flashcards

Analgesia Flashcards

1
Q

what are the 6 main analgesics prescribed

A
  1. aspirin (NSAID)
  2. ibuprofen (NSAID)
  3. diclofenac (NSAID)
  4. paracetamol
  5. dihydrocodeine (opioid)
  6. carbamazepine
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what causes pain

A

production of prostaglandins which sensitise the tissues to other inflammatory products e.g. leukotrienes which results in pain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how are prostaglandins formed

A

trauma/infection lead to breakdown of membrane phospholipids producing arachidonic acid which is then broken down to form prostaglandins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

how to reduce pain

A

decrease prostaglandin production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

describe the arachidonic acid pathway

A

tissue injury -> injury to phospholipid cell membrane causing release of arachidonic acid ->
1. cyclooxygenase pathway (COX-1/COX-2) -> prostaglandin (PGG2) -> prostaglandin H2 (PGH2) -> prostacyclin / prostaglandin (cause pain, inflammation), thromboxane (cause platelet aggregation)
OR
2. 5-lipooxygenase pathway -> leukotrienes (cause bronchoconstriction / asthma attacks / smooth muscle contraction)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

main properties of aspirin

A
  • analgesic
  • antipyretic (prevent / reduce fever)
  • anti inflammatory
  • metabolic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

aspirin mechanism of action

A

inhibits cyclooxygenases (COX 1&2) so reduced production of prostaglandins
more effect at inhibiting COX-1 which reduces platelet aggregation (predisposes to damage of gastric mucosa)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

analgesic properties of aspirin

A

analgesic action exerted both peripherally & centrally
peripheral actions predominate
analgesic action results from inhibition of prostaglandin synthesis in inflamed tissues (COX inhibition)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

antipyretic properties of aspirin

A

prevents temperature rising effects of interleukin-1 and rise in brain prostaglandin levels so reduces elevated temp in fever
NB - doesn’t reduce normal temp

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

anti inflammatory properties of aspirin

A

prostaglandins are vasodilators and as such affect capillary permeability
aspirin = good anti inflammatory and will reduce redness / swelling as well as pain at site of injury

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

adverse effects of prescribing aspirin (4)

A
  1. GIT problems
  2. hypersensitivity
  3. overdose - tinnitus, metabolic acidosis
  4. aspirin burns - mucosal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

describe adverse aspirin effect on GIT

A

mostly on mucosal lining of stomach; prostaglandins PGE2 & PGI2 inhibit gastric acid secretion, increase blood glow through gastric mucosa & help production of mucin by cells in stomach lining (cytoprotective action)
care must be taken for patients with ulcers & GORD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

describe adverse effect of hypersensitivity when prescribing aspirin

A

reactions include:
- acute bronchospasm / asthma type attacks
- skin rashes / urticaria / angioedma
- other allergies
caution when prescribing to asthmatics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

adverse effect of overdose when prescribing aspirin

A
  • hyperventilation
  • tinnitus, deafness
  • vasodilation & sweating
  • metabolic acidosis (can be life threatening)
  • coma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

adverse effect of mucosal burns when prescribing aspirin

A

direct effect of salicylic acid as aspirin applied locally to oral mucosa results in chemical burns. it has no topical effect. ensure it is taken with water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

name 13 groups you should avoid prescribing aspirin to

A
  1. peptic ulceration
  2. epigastric pain
  3. bleeding abnormalities
  4. anticoagulants
  5. pregnancy / breast feeding
  6. patients on steroids
  7. renal / hepatic impairment
  8. u16s
  9. asthmatics - ask if used before and if any problems
  10. hypersensitivity to other NSAIDs
  11. taking other NSAIDs
  12. elderly
  13. G6PD deficiency
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

why avoid prescribing aspirin to those on anticoagulants

A

it enhances warfarin & other coumarin anticoagulants; displaces warfarin from binding sites on plasma proteins and increases free warfarin.
majority of warfarin in bound i.e. inactive so if more is released this will become active thus increasing bleeding tendency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

why avoid prescribing aspirin in pregnancy/lactation

A

esp in 3rd trimester as nearer delivery and may cause impairment of platelet function:
- increased risk of haemorrhage & jaundice in baby
- can prolong / delay labour
contraindicated in breastfeeding - reye’s syndrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

why avoid prescribing aspirin to those on steroids

A

approx 25% of patients on long term systemic steroids will develop a peptic ulcer & if they have undiagnosed ulcer, aspirin will result in perforation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

why avoid prescribing aspirin in renal / hepatic impaired

A

aspirin metabolised in liver & excreted mainly in kidney
if renal impairment excretion may be reduced / delayed
not a complete contraindication but administer with care and avoid if severely impaired

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

relationship between prostaglandins and the kidney

A

prostaglandins PGE2 & PGI2 are powerful vasodilators synthesised in renal medulla and glomeruli respectively & are involved in control of renal blood flow and excretion of salt & water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

inhibition of renal prostaglandin synthesis may result in

A

sodium retention
reduced renal blood flow
renal failure
NSAIDs may cause interstitial nephritis & hyperkalaemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

why avoid prescribing aspirin in u16s

A

reye’s syndrome - up to 50% mortality due to encephalopathy so contraindicated in u16s, avoid during fever or viral infection
fatty degenerative process in liver that causes profound swelling in brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

why avoid prescribing aspirin to those with G6PD deficiency

A

glucose-6-phosphate dehydrogenase deficiency
susceptible to acute haemolytic anaemia and aspirin carries risk of haemolysis in some of these individuals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

what groups is aspirin completely contraindicated in

A
  1. u16s & breast feeding
  2. previous or active peptic ulceration
  3. haemophilia
  4. hypersensitivity to aspirin or any other NSAID
26
Q

ibuprofen v aspirin

A

less effect on platelets
irritant to gastric mucosa but less than aspirin
may cause bronchospasm
paediatric suspension available

27
Q

max adult dose of ibuprofen

A

2.4g

28
Q

8 groups to be cautious of prescribing ibuprofen to

A
  1. previous or active peptic ulceration
  2. elderly
  3. pregnancy & lactation
  4. renal, cardiac or hepatic impairment
  5. history of hypersensitivity to aspirin & other NSAIDs
  6. asthma
  7. patient taking other NSAIDs
  8. patients on long term systemic steroids
29
Q

side effects of ibuprofen

A
  • GIT discomfort, occasionally bleeding & ulceration
  • hypersensitivity reactions e.g. rashes, angioedema & bronchospasm
  • headache, dizziness, insomnia, vertigo, fluid retention etc
30
Q

ibuprofen overdose

A

symptoms = nausea, vomiting, tinnitus
treat = activated charcoal followed by symptomatic measures are indicated if more than 400mg/kg ingested within preceding hr

31
Q

how does paracetamol differ from other NSAIDs

A

it is a simple analgesic without anti-inflammatory activity

32
Q

7 main characteristics of paracetamol

A
  1. analgesic
  2. antipyretic
  3. little or no anti-inflammatory action
  4. no effects on bleeding time
  5. does not interact significantly with warfarin
  6. less irritant to GIT
  7. suitable for children
33
Q

mode of action of paracetamol

A

hydroperoxides are generated from the metabolism of arachidonic acid by COX and exert a positive feedback to stimulate COX activity
this feedback is blocked by paracetamol thus indirectly inhibiting COX especially in the brain

34
Q

main action site of paracetamol

A

the thalamus

35
Q

caution when prescribing paracetamol to

A
  1. hepatic impairment
  2. renal impairment
  3. alcohol dependence
36
Q

side effects of paracetamol

A

are rare but include:
- rashes
- blood disorders
- hypotension reported on infusion
- liver damage following overdose

37
Q

interactions of paracetamol with other drugs

A
  • anticoagulants (prolonged regular use of paracetamol possibly enhances anticoag effects of coumarins)
  • cytotoxics
  • domperidone
  • lipid regulating drugs
  • metoclopramide
38
Q

paracetamol dosage

A

adults - 1-2 500mg tablets 4-6 hourly
children - depends on weight / age

39
Q

max dose paracetamol

A

4g daily i.e. 8 tablets

40
Q

paracetamol overdose

A

as little as 150mg/kg or 20-30 tablets taken in 24hrs can cause severe hepatocellular necrosis or less frequently renal tubular necrosis
liver failure maximal at 3-4 days after ingestion
despite lack of early significant symptoms patients who have overdosed on paracetamol should be transferred immediately to hospital

41
Q

paracetamol, ibuprofen and aspirin are what types of analgesics

A

non opioid analgesics

42
Q

how do opioid analgesics act

A

they act in the spinal cord in dorsal horn pathways - central regulation of pain
they produce their effects via specific receptors which are closely associated with neuronal pathways that transmit pain to CNS

43
Q

opioids and dentistry

A

opioid analgesics are relatively ineffective in dental pain

44
Q

opioid dependence

A

psychological & physical - withdrawal of drug will lead to psychological cravings + ptx will be physically ill

45
Q

opioid tolerance

A

to achieve same therapeutic effects the dose of the drug needs to be progressively increased

46
Q

opioid effect on smooth muscle

A

constipation
urinary & bile retention

47
Q

CNS effects of opioids

A

depresses
- pain centre; alters awareness / perception of pain
- higher centres
- respiratory centre
- cough centre

48
Q

side effects of opioids

A

most common - nausea, vomiting, drowsiness
larger doses - respiratory depression & hypotension
others include - dry mouth, sweating, facial flushing, bradycardia

49
Q

caution prescribing opioids to

A
  • hypotension
  • hypothyroidism
  • asthma
  • decreased respiratory reserve
  • pregnancy / breast feeding
  • hepatic impairment
  • renal impairment
  • elderly & debilitated
  • convulsive disorders
  • dependence
50
Q

contraindications of prescribing opioids

A

acute respiratory depression
acute alcoholism
raised intracranial pressure / head injury - interferes with respiration & affects pupillary responses vital for neurological assessment

51
Q

why use codeine

A

1/12th potency of morphine
effective orally
low dependence
usually in combination with NSAIDs / paracetamol
effective cough suppressant
available over counter

52
Q

what codeine combination is on the dental list

A

dihydrocodeine (orally)

53
Q

dosage of dihydrocodeine

A

30mg every 4-6hrs as necessary
no other mg on dental list

54
Q

side effects of dihydrocodeine

A

same as general opioid e.g. nausea/vomiting, constipation, drowsiness
larger doses - respiratory depression, hypotension

55
Q

serious drug interactions of dihyrocodeine

A

antidepressants MAOIs
dopaminergics (parkinsonism)

56
Q

caution prescribing dihydrocodeine to

A

hypotension
asthma
pregnancy/lactation
renal/hepatic disease
elderly/children
never prescribe in raised intracranial pressure or suspected head injury

57
Q

opioid overdose

A

varying degrees of coma, respiratory depression and pinpoint pupils
specific antidote naloxone indicated if coma/bradypnoea
close monitoring & repeated infusion may be required

58
Q

what neuropathic & functional pain requires analgesics in dentistry

A

trigeminal neuralgia
post herpetic neuralgia
functional - TMJ / atypical face pain

59
Q

what is the only drug on the dental list for neuropathic & functional pain

A

carbamazepine - an anti convulsant
proprietary brand e.g. tegretol

60
Q

drugs that can be used to treat trigeminal neuralgia

A

carbamazepine 100 or 200mg tablets start on 100mg 1-2 x daily but increase according to response to 200mg 3-4 x daily
following 2 not on dental list
gabapentin
phenytoin

61
Q

clinical features of trigeminal neuralgia

A
  1. severe spasms of pain ‘electric shock’ lasts seconds
  2. usually unilateral
  3. trigger spot identified
  4. F > M
  5. older age group
  6. periods of remission
  7. recurrences often greater severity

BDS3 Oral Surgery (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions