Analgesia in Dentistry Flashcards
What happens in the arachidonic acid pathway?
Trauma and infection lead to the breakdown of membrane phospholipids producing arachidonic acid
This can be broken down to form prostaglandins
Prostaglandins sensitise the tissues to other inflammatory products, resulting in pain
Why do drugs aim to reduce prostaglandin production?
Prostaglandins don’t directly cause pain but sensitise tissues to other inflammatory products such as leukotrienes
If prostaglandin production decreases, this will moderate the pain
What are the properties of aspirin?
Analgesic
Antipyretic
Anti-inflammatory
What is aspirin’s mechanism of action?
Aspirin inhibits COX 1 and 2, reducing prostaglandin production
What are the adverse effects of aspirin?
GIT problems
Hypersensitivity
Overdose can cause tinnitus and metabolic acidosis
Aspirin mucosal burns due to salicylic acid
Give examples of groups that should avoid aspirin
Peptic ulceration - can cause perforation
Epigastric pain
Bleeding abnormalities ie - haemophilia
If on anticoagulants - aspirin enhances these
If under 16 - can cause Reye’s syndrome
Which groups should be cautious when taking aspirin?
Pregnancy/lactation - especially 3rd trimester
Patients on steroids as they may have a peptic ulcer
Renal/hepatic impairment - aspirin metabolised in liver and excreted in kidney
Hypersensitivity to/taking other NSAIDS
Elderly - more susceptible to drug induced side effects
G6PD deficient
What is Reye’s syndrome?
Fatty degenerative process in liver, profound swelling in brain
Up to 50% mortality
Caused by under 16s taking aspirin
What are the contraindications to aspirin?
Under 16s
Those breastfeeding
Previous or active ulceration
Haemophilia
Hypersensitivity to aspirin or other NSAIDs
What is the dosage of aspirin?
300mg tablets
2 tablets, 4 times daily, preferably after food
2.4g daily
Why is ibuprofen used?
Similar but not identical effect as aspirin
Less effect on platelets
Irritant to gastric mucosa but lower risk than aspirin
Paediatric suspension available
What is the adult dosage of ibuprofen?
400mg tablets
1 tablet 4 times daily, preferably after food
1.6g daily
In which groups should you be cautious when prescribing ibuprofen?
Previous or active peptic ulceration
The elderly
Pregnancy and lactation
Renal, cardiac or hepatic impairment
Hypersensitivity to aspirin/other NSAIDS
Asthma
If taking other NSAIDs
Patients on long term systemic steroids
Give examples of some side effects of ibuprofen
GIT discomfort, occasionally bleeding and ulceration
Hypersensitivity reactions eg rashes, bronchospasm
Headache
Dizziness
Drowsiness
What are some potential drug interactions of ibuprofen?
ACE inhibitors
Anticoagulants
Antidepressants
Corticosteroids
What are the symptoms of ibuprofen overdose?
Nausea
Vomiting
Tinnitus - more serious toxicity very uncommon
How may an ibuprofen overdose be treated?
Activated charcoal following symptoms if more than 400mg/kg has been ingested in the preceding hour
What are the properties of paracetamol?
Analgesic
Antipyretic
Little or no anti-inflammatory action
No effects on bleeding time
Doesn’t interact significantly with warfarin
Less irritant to GIT
Suitable for children