Analgesia in Oral Surgery (c) Flashcards
When should systemic analgesics be started?
systemic analgesics should be started before the local anaesthetic wears off
What analgesics are contained within the Dental Practitioner’s Formulary?
analgesics in the Dental Practitioner’s Formulary:
- aspirin (NSAID)
- ibuprofen (NSAID)
- diclofenac (NSAID)
- paracetamol
- dihydrocodeine (opoid)
- carbamazepine
What do the following drugs have in common?:
- aspirin
- ibuprofen
- diclofenac
aspirin, ibuprofen and diclofenac are all NSAIDs
Is paracetamol an NSAID?
no, paracetamol is not an NSAID
What type of drug is dihydrocodeine?
dihydrocodeine is an opioid
Aspirin has X anti-inflammatory properties to paracetamol
X - superior
Aspirin is less commonly used in dentistry now, X is more commonly used
X - ibuprofen
Can aspirin be bought over the counter?
yes, aspirin can be bought over the counter
What properties does aspirin have?
aspirin has the following properties:
- analgesic
- antipyretic
- anti-inflammatory
- anti-platelet
- metabolic
What is acetylsalicylic acid also known as?
acetylsalicylic acid = aspirin
Trauma and infection lead to the breakdown of membrane X, producing arachidonic acid
X - phospholipids
Trauma and infection lead to the breakdown of membrane phospholipids, producing what?
trauma and infection lead to the breakdown of membrane phospholipids, producing arachidonic acid
What can arachidonic acid be broken down to form?
arachidonic acid can be broken down to form prostaglandins
What can be broken down to form prostaglandins?
arachidonic acid can be broken down to form prostaglandins
Arachidonic acid can be broken down to form X, which sensitise tissues to other inflammatory products which which results in pain
X - prostaglandins
Do prostaglandins directly cause pain?
no, prostaglandins do not directly cause pain
Prostaglandins do not directly cause pain but they sensitise tissues to other X such as leukotrienes
X - inflammatory products
What will happen if prostaglandin production decreases?
if prostaglandin production decreases then this will moderate pain
What does aspirin reduce the production of?
aspirin reduces the production of prostaglandins
Aspirin reduces the production of prostaglandins and inhibits X
X - COX 1 and 2 (cyclo-oxygenases 1 and 2)
Is aspirin more effective at inhibiting COX 1 or 2?
aspirin is more effective at reducing COX 1
X inhibition by aspirin reduces platelet aggregation and predisposes to damage of the gastric mucosa
X - COX-1
Aspirin is mainly a X acting agent
X - peripherally
The analgesic action of NSAIDs is exerted both peripherally and X
X - centrally
The analgesic action of aspirin results from inhibition of prostaglandin synthesis in X
X - inflamed tissues
Aspirin prevents the temperature X effects of interleukin-1
X - rising
Aspirin prevents the temperature rising effects of X
X - interleukin 1
Aspirin prevents the temperature raising effects of interleukin-1 and the rise in brain X levels
X - prostaglandin
How does aspirin reduce elevated temperature in fever?
aspirin reduces elevated temperature in a fever by preventing:
- temperature raising effects of interleukin-1
- the rise in brain prostaglandin levels
Does aspirin reduce normal body temperature?
no, aspirin does not reduce normal body temperature
Prostaglandins are X so therefore affect capillary permeability
X - vasodilators
Is aspirin a good anti-inflammatory?
yes, aspirin is a good anti-inflammatory and will reduce redness and swelling as well as pain at the site of injury
What does aspirin do to basal metabolic rate?
aspirin increases basal metabolic rate
What does aspirin do to blood sugar?
aspirin decreases blood sugar
What are adverse effects of aspirin?
aspirin - adverse effects:
- GIT problems
- hypersensitivity
- overdose
- tinnitus
- metabolic acidosis
- aspirin burns (mucosal)
Where are most GIT problems caused from aspirin found?
most GIT problems caused by aspirin are found on the mucosal lining of the stomach
Prostaglandins X blood flow through the gastric mucosa
X - increase
Prostaglandins help production of X by cells in the stomach lining (cytoprotective action)
X - mucin
Patients with what types of GIT problems should care be taken with when giving aspirin?
GIT problems to be careful of when using aspirin:
- ulcers
- gastro-oesophageal reflux
What are hypersensitivity reactions that may occur due to the use of aspirin?
aspirin - possible hypersensitivity reactions:
- acute bronchospasm/asthma type attacks
- minor skin rashes
- other allergies
When prescribing aspirin, what condition should you be being mindful of (thinking about hypersensitivity)?
take care when prescribing aspirin to asthmatics
What can happen in aspirin overdose?
adverse effects of aspirin overdose:
- hyperventilation
- tinnitus/deafness
- vasodilation and sweating
- metabolic acidosis (can be life threatening)
- coma (uncommon)
Aspirin can casue mucosal burns due to the direct effect of X
X - salicylic acid
If aspirin is applied locally to oral mucosa, what does it result in?
if aspirin is applied locally to oral mucosa, it results in chemical burns
Does aspirin have a topical effect?
no, aspirin does not have a topical effect
What should aspirin be taken with?
aspirin should be taken with water
What general groups of people should you apply caution or implement avoidance with when prescribing aspirin?
aspirin - groups to avoid/be cautious of:
- peptic ulceration
- epigastric pain
- bleeding abnormalities
- anticoagulants
- pregnancy/breastfeeding
- patients on steroids
- renal/hepatic impairment
- children and adolescents under 16 years old
- asthma
- hypersensitivity to other NSAIDs
- taking other NSAIDs
- elderly
- G6PD-deficiency
Why should aspirin be avoided in patients with peptic ulceration?
aspirin should be avoided in patients with peptic ulceration as their gastric or duodenal ulcer could perforate
Aspirin X warfarin and other coumarin anticoagulants
X - enhances
How does aspirin enhance warfarin and other coumarin anticoagulants?
aspirin enhances warfarin and other coumarin anticoagulants as it displaces warfarin from binding sites on plasma proteins
Aspirin X free warfarin in patients on warfarin
X - increases
The majority of warfarin is X (inactive)
X - bound
The majority of warfarin is bound (X)
X - inactive
The majority of warfarin is bound (inactive). If more is released then this will become active, X bleeding tendency
X - increasing
Aspirin should be avoided in pregnancy (especially in the X trimester) and lactation
X - 3rd
Why shoudl aspirin especially be avoided in the 3rd trimester of pregnancy?
aspirin should especially be avoided in the 3rd trimester of pregnancy as this is near the time of delivery and may cause impairment of platelet function
Why is aspirin contraindicated in breastfeeding?
aspirin is contraindicated in breastfeeding as it has been known to cause Reye’s syndrome
Why should patients on steroids not be prescribed aspirin?
patients on steroids should not be prescribed aspirin as approximately 25% of patient on steroids long term will develop a peptic ulcer. If this ulcer is undiagnosed, aspirin may result in a perforation
Where is aspirin metabolism carried out?
aspirin metabolism is carried out in the liver
Where is aspirin mainly excreted from?
aspirin is mainly excreted from the kidney
What can be said about aspirin excretion if there is renal impairment?
if there is renal impairment, aspirin excretion may be reduced or delayed
Prostaglandins X and PGI2 are powerful vasodilators synthesised in the renal medulla and glomeruli and are involved in the control of renal blood flow and excretion of salt and water
X - PGE2
Prostaglandins PGE2 and PGI2 are powerful X synthesised in the renal medulla and glomeruli respectively and are inolved in the control of renal blood flow and excretion of salt and water
X - vasodilators
What may inhibition of renal prostaglandins synthesis may result in?
inhibition of renal prostaglandin synthesis may result in:
- sodium retention
- reduced renal blood flow
- renal failure
What is prolonged analgesic abuse over a period of years associated with?
prolonged analgesic abuse over a period of years is associated with papillary necrosis and chronic renal failure
What is Reye’s syndrome?
Reye’s syndrome is a fatty degenerative process in the liver
Reye’s syndrome leads to profound X in the brain
X - swelling
Are NSAIDs completely ocntraindicated in asthmatics?
no, NSAIDs are not completely contraindicated in asthmatics as some asthmatics have no problem with them
Is aspirin a contraindication in patients with a history of hypersensitivity to aspirin or another NSAID?
yes, aspirin is a contraindication in patients with a history of hypersensitivity to aspirin or other NSAIDs
What can be said about the risk of side effects when NSAIDs are taken in combination?
when NSAIDs are taken in combination, there is an increased risk of side effects
Elderly patients are X susceptible to drug induced side effects in general
X - more
Why are elderly patients more susceptible to drug induced side effects in general?
elderly patients are more susceptible to drug induced side effects in general as they often:
- have a smaller circulating blood volume
- are smaller in size
- are on other medications
- have other medical problems
Wha are individuals with G6PD-deficiency susceptible to developing?
individuals with G6PD-deficiency are susceptible to developing acute haemolytic anaemia on taking a number of common drugs
Aspirin carries a possible risk of X in some G6PD-deficient individuals
X - haemolysis
In what groups of people is aspirin definitely contraindicated?
aspirin is CONTRAINDICATED in the following groups:
- children and adolescents under 16 years old (Reye’s syndrome)
- breastfeeding mothers (Reye’s syndrome)
- previous or active peptic ulceration
- haemophilia
- hypersensitivity to aspirin or any other NSAID
What is long term use of ibuprofen associated with an increased risk of?
long term use of ibuprofen is associated with an increased risk of cardiac events
Is ibuprofen an NSAID?
yes, ibuprofen is an NSAID
Ibuprofen has X of an effect on platelets compared to aspirin
X - less
Ibuprofen is an irritant to gastric mucosa, but has a X risk than aspirin
X - lower
What is the maximum dose of ibuprofen in adults?
the maximum dose of ibuprofen in adults is 2.4g
What groups should you give caution to when prescribing ibuprofen?
give caution when prescribing ibuprofen to the following groups:
- previous or active peptic ulceration
- elderly
- pregnancy and lactation
- renal, cardiac or hepatic impairment
- history of hypersensitivity to aspirin and other NSAIDs
- asthma
- patients taking other NSAIDs
- patients on long term systemic steroids
What are some side effects of ibuprofen?
ibuprofen side effects:
- GIT discomfort, occasionally bleeding and ulceration
- hypersensitivity reactions such as rashes, angioedema and bronchospasm
- others:
- headache
- dizziness
- nervousness
- depression
- drowsiness
- insomnia
- vertigo
- hearing disturbance/tinnitus
- photosensitivity
- haematuria
- blood disorders
- fluid retention
- renal impairment
- hepatic damage
- pancreatitis
- eye changes
- Stevens-Johnson syndrome
What are symptoms of ibuprofen overdose?
symptoms of ibuprofen overdose:
- nausea
- vomiting
- tinnitus (more serious toxicity very uncommon)
What is indicated if more than 400mg/kg of ibuprofen has been ingested within the preceding hour?
activated charcoal followed by symtomatic measures are indicated if more than 400mg/kg of ibuprofen has been ingested within the preceding hour
What do NSAIDs inhibit?
NSAIDs inhibit cyclo-oxygenases
NSAIDs inhibit cyclo-oxygenases and so reduce X (which sensitise the tissues to other inflammatory mediators, resulting in pain)
X - prostaglandins
COX1 is the cyclo-oxygenase predominantly responsible for catalysing the reaction that produces prostaglandins associated with what?
COX1 is the cyclo-oxygenase predominantly responsbile for catalysing the reaction that produces prostaglandins associated with:
- platelet aggregation
- protection of the gastric mucosa
COX2 is the enzyme responsible for the generation of most of what?
COX2 is the enzyme responsible for the generation of most of the inflammatory prostaglandins
What do the actions of the formed prostaglandins depend on?
the actions of the formed prostaglandins depends on:
- the pathological situation
- whether they are formed by COX1 or COX2
- whether they are formed in excessive amounts
Should you use more than one oral NSAID at a time?
no, you should not use more than one oral NSAID at a time
What is an example of a selective COX2 inhibitor?
celecoxib (celebrex) is a selective COX2 inhibitor
What patients may COX2 selectives be chosen to manage dental pain in?
COX2 selectives should be chosen to manage dental pain only in patients at a high risk of gastric or duodenal ulceration (e.g. those with a history of a peptic ulcer)
Do highly selective COX2 inhibitors have an effect on platelet aggregation?
no, highly selective COX2 inhibitors do not have an effect on platelet aggregation
What is the name of a simple analgesic without the anti-inflammatory activity?
paracetamol is a simple analgesic without the anti-inflammatory activity
What drug is also known as acetaminophen?
acetaminophen = paracetamol
X are generated from the metabolism of arachidonic acid by COX and exert a positive feedback to stimulate COX activity
X - hydroperoxides
Hydroperoxides are generated from the metabolism of arachidonic acid by COX and exert a positive feedbak to stimulate COX activity. This feedback is blocked by X, thus indriectly inhibiting COX (especially in the brain)
X - paracetamol
A small component of the analgesic action of all NSAIDs is the reduction of X in the pain pain pathways of the CNS (such as the thalamus) - this is the main site of action of paracetamol
X - prostaglandins
What is the main action of paracetamol?
the main action of paracetamol is the reduction of prostaglandins in the pain pathways of the central nervous system (such as in the thalamus)
Since paracetamol does not appear to have much effect on peripheral prostaglandins, there is little/no X irritation
X - gastric mucosal
Is there gastric mucosal irritation with paracetamol?
there is little/no gastric mucosal irritation with paracetamol
Why is paracetamol considered a “safe analgesic”?
paracetamol is considered a “safe analgesic” as there is little/no gastric mucosal irritation
What groups of people should you be cautious of when prescribing paracetamol?
cautions when prescribing paracetamol to the following groups:
- hepatic impairment
- renal impairment
- alcohol dependence
Side effects of paracetamol are rare, but what are possible side effects?
possible side effects with paracetamol:
- rashes
- blood disorders
- hypotension reported on infusion
- liver damage (and, less frequently, kidney damage) following overdose
What does paracetamol have interactions with?
paracetamol interactions:
- anticoagulants (prolonged regular use of paracetamol possibly enhances the anticoagulant effects of the coumarins)
- cytotoxics
- domeperidone
- lipid-regulating drugs
- metoclopramide
What warning should you always give patients with regards to paracetamol?
with regards to paracetamol, always warn patients about the maximum dose and emphasise that they should not exceed this
As little as 10-15g (20-30 tablets) or 150mg/kg of paracetamol taken within 24 hours may cause severe X and, less frequently, renal tubular necrosis
X - hepatocellular necrosis
What should you do with patients who have taken an overdose of paracetamol?
if a patient has taken an overdose of paracetamol, you should transfer them to hospital immediately
What can be said about the early symptoms of paracetamol overdose?
there is a lack of significant early symptoms of paracetamol overdose
Does co-codamol contain paracetamol?
yes, co-codamol contains paracetamol
Does co-proxamol contain paracetamol?
yes, co-proxamol contains paracetamol
What opioid analgesic are dentists allowed to prescribe?
dentists can prescribe dihydrocodeine, whcih is an opioid analgesic
Where do opioid analgesics act?
opioid analgesics act in the spinal cord
What is the term used for both naturally occurring and synthetic molecules that produce their effects by combining with opioid receptors?
opioids is the term used for both naturally occurring and synthetic molecules that produce their effects by combining with opioid receptors
Are opioid analgesics effective in dental pain?
opioids analgesics are relatively ineffective in dental pain
What is opioid dependence?
opioid dependence is when a patient has withdrawal of the drug and this will lead to psychological cravings and the patient will also be physically ill
What is opioid tolerance?
opioid tolerance is when an increased dose of the drug is needed to be given to achieve the same effects
What effects do opioids have on smooth muscle?
effects of opioids on smooth muscle:
- constipation (can occur after a few doses of dihydrocodeine)
- urinary and bile retention
What do opioid analgesics depress?
opioid analgesics have a CNS effect and depress:
- pain centre (alters awareness/perception of pain)
- higher centres
- respiratory centre
- cough centre
- vasomotor
What do CNS effects do opioid analgesics stimulate?
opioid analgesics ahve CNS effects and stimulate:
- vomiting centre (dihydrocodeine often causes nausea and vomiting which limits its value in dental pain)
- salivary centre
- pupillary constriction
What are the most common side effects of opioids?
most common side effects of opioids:
- nausea
- vomiting
- drowsiness
What side effects can large doses of opioids produce?
large doses of opioids can produce respiratory depression and hypotension
What substance can enhance the effects of opioids?
the effects of opioids are enhanced by alcohol
What should you be cautious of when prescribing opioids?
cautions with opioids:
- hypotension
- hypothyroidism
- asthma
- decreased respiratory reserve
- prostatic hyperplasia
- pregnancy/breastfeeding
- hepatic impairment
- renal impairment
- elderly and debilitated (reduced dose)
- convulsive disorders
- dependence
What are contraindications of opioids?
contraindications of opioids:
- acute respiratory depression
- acute alcoholism
- riased intracranial pressure/head injury
What is the only codeine combination on the Dental Practitioner’s Formulary?
the only codeine combination on the Dental Practitioner’s Formulary is dihydrocodeine
What is the potency of dihydrocodeine similar to?
the potency of dihydrocodeine is similar to codeine
What are the routes of dihydrocodeine?
dihydrocodeine routes:
- subcutaneous (controlled drug)
- intramuscular (controlled drug)
- oral (not controlled)
What are drug interactions to be aware of when prescribing dihydrocodeine?
dihydrocodeine interactions:
- antidepressants
- dopaminergics
Can opioids be prescribed when there is raised intracranial pressure or suspected head injury?
no, opioids cannot be prescribed when there is rasied intracranial pressure or suspected head injury
What can be said about the value of dihydrocodeine for dental pain?
dihydrocodeine is of little value for dental pain
Is dihydrocodeine effective for post-operative dental pain?
no, dihydrocodeine is not effective for post-operative dental pain
What are examples of functional pain?
functional pain:
- TMJ pain
- atypical facial pain
What is the only drug presently on the dental list for neuropathic and functional pain?
the only drug at present on the dental list for neuropathic and functional pain is carbamazepine
What drug can be used to control trigeminal neuralgia?
carbamazepine can be used to control trigeminal neuralgia
What are clinical features of trigeminal neuralgia?
clinical features of trigeminal neuralgia:
- severe spasms of pain (electric shock)
- lasting seconds
- usually unilateral
- trigger spot identified
- periods of remission
- recurrences often greater severity
What age group does trigeminal neuralgia tend to happen in?
trigeminal neuralgia tends to happen in older age groups
Does trigeminal neuralgia tend to happen more in males or females?
trigeminal neuralgia tends to happen more in females than males
What are side effects of carbamazepine?
side effects of carbamazepine:
- dizziness
- ataxia
- drowsiness
- leucopenia and other blood disorders
What are contraindications for carbamazepine?
carbamazepine contraindications:
- AV conduction abnormalities (unless paced)
- history of bone marrow depression
- porphyria
What should you be cautious of when prescribing carbamazepine?
carbamazepine cautions:
- hepatic/renal/cardiac disease
- skin reactions
- history of haematological reactiosn to other drugs
- glaucoma
- pregnancy/breastfeeding
- avoid abrupt withdrawal
