Analgesia Flashcards
what controls pain during dental procedures
local anaesthetic
what controls post operative pain
systemic analgesic drugs
name some artificial saliva substitutes
BioXtra
Saliveze
what are the analgesics in the dental practitioners formulary
aspirin
ibuprofen
diclofenac
paracetamol
dihydrocodeine
carbamazepine
what is the pain pathway called
arachidonic acid pathway
when is arachidonic acid produced
when there is injury to phospholipid cell membrane
what are the two outcomes that can be produced from arachidonic acid
prostaglandins or leukotrienes
what occurs when prostaglandins are produced from the arachidonic acid pathway
causes pain and inflammation
what occurs when leukotrienes are produced from the arachidonic acid pathway
causes bronchoconstriction, asthma attacks and smooth muscle contractions
what sensitises the tissues to other inflammatory products which can cause pain
prostaglandins
what is the function of prostaglandins
to sensitise the tissues to other inflammatory products such as leukotrienes which causes pain
what type of drug is aspirin
NSAID
what are the four properties of aspirin
analgesic
antipyretic
anti-inflammatory
metabolic
what is the chemical name for aspirin
acetylsalicylic acid
how does aspirin work
it inhibits the cyclo-oxygenases and therefore reduces production of prostaglandins
what COX is aspirin more effective at inhibiting
COX 1
what occurs when COX 1 is inhibited
reduces platelet aggregation and predisposes to damage of the gastric mucosa
where does action of aspirin occur
peripherally and centrally
do peripheral or central actions predominate for aspirin
peripheral
what are the analgesic properties of aspirin
it inhibits the prostaglandin synthesis in inflamed tissue by COX inhibition
what are the antipyretic properties of aspirin
prevents temperature raising effects of interleukin-1 and rise in brain prostaglandin level and so reduces elevated temperature
what are the anti-inflammatory properties of aspirin
prostaglandins are vasodilators and affect capillary permeability - apirin inhibits this
what are adverse effects of aspirin
GIT problems
hypersensitivity
overdose
aspirin burns
how does aspirin cause GIT problems
prostaglandins inhibit gastric acid secretion and also increase blood flow to gastric mucosa to help production of mucin by cells in stomach lining
what are hypersensitivity effects of aspirin
acute bronchospasm, asthma type attacks
skin rashes/ urticaria/ angioedema
what are effects of an overdose of aspirin
hyperventilation
tinnitus, deafness
vasodilation and sweating
what are aspirin related mucosal burns
direct effect of salicylic acid - when applied to the mucosa
who do you have to take caution with when prescribing aspirin
peptic ulceration
bleeding abnormalities
anitcoagulants
asthma
why should people with peptic ulcerations avoid taking aspirin
gastric or duodenal ulcer could result in perforation
why should patients taking anti-coagulant be cautious with taking aspirin
aspirin enhances warfarin and other coumarin anticoagulants and displaces warfarin from binding sites on plasma protein which increases free warfarin - increases bleeding
why should aspirin be avoided in pregnant women
causes impairment of platelet function which is increased risk of haemorrhage, increased jaundice in the baby and can prolong/ delay labour
why should patients on steroids not be taking aspirin
patients on long term steroids will develop peptic ulcers - which could result in perforation
why should patients with renal/ hepatic impairment avoid aspirin
aspirin is metabolised in the liver and excreted in the kidney
what might inhibition of prostaglandin synthesis result in
sodium retention
reduced renal blood flow
renal failure
what are two effects related to the kidney that NSAIDs might have
interstitial nephritis and hyperkalaemia
what can occur if a breastfeeding mother takes aspirin
Reye’s syndrome
what is Reye’s syndrome
fatty degenerative process in the liver and profound swelling in the brain
in what groups of people is aspirin completely contra-indicated
children under 16
previous or active peptic ulceration
haemophilia
hypersensitivity to aspirin or NSAIDs
what is the prescription of aspirin for odontogenic pain
2 x tablets, 4 x daily
300mg
what should be prescribed to patients with peptic ulcers with odontogenic pain
lansoprazole - proton pump inhibitor
what is the prescription for ibuprofen for odontogenic pain
1 tablet 4x daily 400mg
what is the max dose of ibuprofen for an adult
2.4g
what are the main side effects of ibuprofen
GIT discomfort, bleeding and ulceration
hypersensitivity reactions
what are symptoms of ibuprofen overdose
nausea
vomiting
tinnitus
how is ibuprofen overdose treated
activated charcoal followed by symptomatic measures
what is paracetamol
a simple analgesic without any anti-inflammatory activity
does paracetamol interact significantly with warfarin
no
how does paracetamol work
blocks the feedback of hydroperoxides which stimulate COX activity - especially in the brain
what is the three modes of action of paracetamol
analgesia
antipyretic action
no reduction in peripheral inflammation
what is the main site of action of paracetamol
thalamus
what are three contraindications of paracetamol
hepatic impairment
renal impairment
alcohol dependence
what is the prescription for paracetamol for odontogenic pain
2 tablets 4xdaily 500mg
what is the max dose for paracetamol
4g daily
what are examples of opioid analgesics
codeine
dihydrocodeine
fentanyl
where do opioid analgesics take their effect
they act in the spinal cord in the dorsal horn pathways
do opioid analgesics cause peripheral or central regulation of pain
central
how do opioid analgesics work
specific receptors that are closely associated with neuronal pathways that transmit pain to the CNS
what are problems with opioids
dependence
tolerance
constipation
urinary and bile retention
what effects do opioids have on the CNS
pain centre
higher centres
respiratory centre
cough centre
what is a dental related side effect of opioids
dry mouth
what are contra-indications of opioids
hypotension
hypothyroidism
asthma
decreased respiratory reserve
pregnant
what is codeine
natural alkaloid found in opium poppy
what is the only codeine combination on the dental list
dihydrocodeine
what are routes of entry for dihydrocodeine
subcutaneous
intra muscular
oral
what are side effects of dihydrocodeine
nausea
constipation
drowsiness
what are the main interactions with dihydrocodeine
antidepressants
dopaminergics
when should you never prescribe dihydrocodeine
in raised intra-cranial pressure or suspected head injury
is dihydrocodeine effective for dental pain or post-operative dental pain
no
what occurs in an opioid overdose
varying degrees of coma and respiratory depression and pinpoint pupils
what is the specific antidote for opioid overdose
naloxone
what is neuropathic pain in dentistry
trigeminal neuralgia
post-herpetic neuralgia
what is functional pain in dentistry
TMJ or atypical facial pain
what is the only neuropathic drug for dental pain we use
carbamazepine which is used to control trigeminal neuralgia
what drugs can be used to treat trigeminal neuralgia
gabapentin
phenytoin
both not on dental list
what are features of trigeminal neuralgia
severe spasms of pain
unilateral
periods of remission
what is the prescription of carbamazepine for trigeminal neuralgia
starting dose 100mg 2xdaily
usual dose 200mg 3-4 times daily
