Analgesics in oral surgery Flashcards
What are the analgesia considerations?
- “think” postoperative analgesia
- start systemic analgesics before the local anaesthetic wears off
- “Sell” the prescription to obtain optimal response
- Use local anesthetics more
- Watch for risk groups
What analgesics are included in the dental practitioners formulary
- Asprin (NSAID)
- Ibuprofen (NSAID)
- Diclofenac (NSAID)
- Paracetamol
- Dihydrocodeine (opioid)
- Carbamazepine
what do we need to know about the drugs we prescribe for analgesia
- mechanism of action
- doses
- side effects
- interactions
- groups of patients to avoid
what pain aspirin effective for
dental and TMJ
what has superior anti-inflammatory properties: aspirin or paracetamol
aspirin
can aspirin be bought over the counter
yes
what effects does aspirin have
- analgesic
- antipyretic
- anti-inflammatory
- anti-platelet
- metabolic
how does pain occur from trauma to the mouth
- trauma and infection lead to the breakdown of membrane phospholipids producing arachidonic acid
- arachidonic acid can be broken down to form prostaglandins
- prostaglandins sensitise the tissues to other inflammatory products which results in pain
why does reducing prostaglandin production moderate pain
- prostaglandins don’t cause pain directly
- they sensitise the tissues to other inflammatory products such as leukotrienes
what enzymes convert arachidonic acid to result in inflammatory mediators being produced
cyclo-oxygenases (COX-1 and COX-2)
what is the mechanism of action of aspirin
- reduces production of prostaglandins
- inhibits cyclo-oxygenases
- more effective at inhibiting COX-1 (by 150x) therefore reducing platelet aggregation and predisposes to damage of the gastric mucosa
what are the analgesic properties of aspirin
- mainly a peripherally acting agent
- inhibition of prostaglandin synthesis in inflamed tissues (cyclo-oxygenase inhibition)
what are the antipyretic properties of aspirin
- reduces temperature during a fever (doesn’t alter normal)
- happens by preventing temp raising effects of interleukin-1 and the rise in brain prostaglandin levels
what are the anti-inflammatory properties of aspirin
- reduces redness, swelling and pain at site of injury
what are the metabolic effects of aspirin
- increased BMR
- platelets
- prothrombin
- decreased blood sugar
what adverse effects does aspirin have
- GIT problems
- hypersensitivity
- overdose- tinnitus, metabolic acidosis
- aspirin burns-mucosal
How does aspirin cause GIT problems
- mainly mucosal lining of stomach
- prostaglandins inhibit gastric acid secretion, increase blood flow through the gastric mucosa and help prodution of mucin by cells in stomach lining (cytoprotective action)
- care must be taken in pt’s with GIT problems e.g. ulcers or gasto-oesophageal reflux
what hypersensitivity reactions does aspirin cause
- acute bronchospasm/asthma type attacks (care when prescribing to asthmatics)
- minor skin rashes
- other allergies
what can an overdose in aspirin result in
- hyperventilation
- tinnitus, deafness
- vasodilation and sweating
- metabolic acidosis
- coma
why can aspirin cause mucosal burns
- direct effect of salicylic acid
- aspirin applied locally to oral mucosa results in chemical burns
- aspirin has no topical effect
- ensure aspirin is taken with water
what groups should be avoided/caution with aspirin
- peptic ulceration
- epigastric pain
- bleeding abnormalities
- anticoagulants
- pregnancy/breast-feeding
- patients on steroids
- renal/hepatic impairment
- children/adolescents under 16 years
- asthma
- hypersensitivity to other NSAIDs
- Taking other NSAISs
- Elderly
- G6PD-deficiency
why should people with peptic ulcerations not have aspirin
gastric or duodenal ulcer could result in perforation
why should people with epigastric pain not have aspirin
potential ulcer??
history of epigastric pain/discomfort or gastro-oesophageal reflux but no ulcer diagnosed
why should people on anticoagulants avoid aspirin
- aspirin enhances warfarin and other coumarin anticoagulants (displaces warfarin from binding sites on plasma proteins and increases free warfarin)
- the majority of warfarin is bound (inactive). If more is released this will become active increasing bleeding tendency