Analgesia Part 1 Flashcards
(41 cards)
What are 5 analgesia considerations?
- Think postoperative analgesia
- Start systemic analgesia before the LA wears off
- Sell the prescription to obtain optimal response
- Use LA more
- Watch for risk groups
Where can you find more information about the drugs that dentists can prescribe?
BNF, dental practitioners formulary and SDCEP.
What group of drugs does aspirin belong to?
NSAIDS.
How are prostaglandins produced to create pain?
Trauma and infection lead to the breakdown of membrane and 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. Prostaglandins do not cause pain directly but they sensitise the tissues to other inflammatory products such as leukotrienes. So, if prostaglandin production decreases this will moderate the pain.
What is the mechanism of action for aspirin?
Aspirin reduces production of prostaglandins. It inhibits cyclo-oxygenases (COX 1 and 2). It is more effective at inhibiting COX 1. COX 1 inhibition reduces platelet aggregation and predisposes to damage of the gastric mucosa.
How does aspirin create an analgesic effect?
Analgesic action of NSAIDs is exerted both peripherally and centrally. Peripheral actions predominate. The analgesic action results from inhibition of prostaglandins synthesis in inflamed tissues (cyclo-oxygenase inhibition).
How does aspirin have antipyretic properties?
Aspirin prevents the temperature raising effects of interleukin-1 and the rise in brain prostaglandin levels and so reduces elevated temperature in fever, doesn’t reduce normal temperature.
How does aspirin have anti-inflammatory properties?
Prostaglandins are vasodilators and as such also affect capillary permeability. Aspirin is a good anti-inflammatory and will reduce redness and swelling as well as pain at the site of injury
What are the metabolic effects of aspirin?
BMR (basal metabolic rate) increase
Platelets
Prothrombin
Decrease blood sugar.
What are adverse effects of aspirin?
GIT problems
Hypersensitivity
Overdose= tinnitus, metabolic acidosis
Aspirin burns (mucosal).
How can aspirin negatively effect the GIT?
Mostly on mucosal lining of the stomach
Prostaglandins (PGE2 and PGI2) inhibit gastric secretion, increase blood flow through the gastric mucosa and help the production of mucin by cells in the stomach lining (cytoprotective action). Most patients taking aspirin will suffer some blood loss from the GIT (not detectable macroscopically and is asymptomatic).
What side effects can you get from as aspirin overdose?
Hyperventilation Tinnitus Deafness Vasodilation and swelling Metabolic acidosis Coma.
What are some adverse hypersensitivity reactions that you can get from taking aspirin?
Acute bronchospasm/asthma type attacks
Minor skin rashes
Other skin allergies
TAKE CARE WHEN PRESCRIBING TO ASTHMATICS.
Why must you ensure that the patient takes aspirin with water?
You can get mucosal burns from the direct effect of salicylic acid. Aspirin applied locally to oral mucosa results in chemical burns- it has NO topical effect.
What groups of patients should you take caution with when prescribing aspirin?
Peptic ulceration Epigastic pain Bleeding abnormalities Anticoagulants Pregnancy/breast feeding Patients on steroids (increase aspirin side effects and about 25% of patients taking steroids will have a peptic ulcer) Renal/hepatic impairment Children under 26 Asthma Hypersensitivity to other NSAIDs (includes those that have has asthma attacks, angiooedema, urticaria or rhinitis that has been precipitated by any NSAID) Taking other NSAIDS Elderly G6PD- deficiency.
Why should you avoid giving peptic ulceration patients aspirin?
Gastric or duodenal ulcer could result in perforation.
Why should we avoid giving anticoagulant patients warfarin?
Aspirin enhances warfarin and other coumarin anticoagulants. It displaces warfarin from binding sites on plasma and increases free warfarin. The majority of warfarin in bound (inactive). If more is released this will become active increasing bleeding tendency.
Why should we avoid giving pregnant women aspirin?
Especially during the third trimester as this is nearer the delivery and may cause impairment of platelet function. This might result in an increased risk of haemorrhage, jaundice in the baby and can prolong labour. It is contraindicated in breastfeeding (might cause Reye’s syndrome).
Why should we avoid giving patients with renal or a hepatic impairment aspirin?
Aspirin metabolism in liver and excretion mainly in the kidney. If renal impairment excretion might be delayed. Not a complete contraindication but administer with care/reduce dose and avoid if renal or hepatic impairment severe.
How does aspirin cause nephrotoxicity?
Prostaglandins PGE2 and PGI2 are powerful vasodilators synthesised in the renal medulla and glomeruli respectively, and are involved in the control of renal blood flow and excretion of salt and water. Inhibition of renal prostaglandin synthesis may result in: sodium retention, reduced renal blood flow and renal failure. NSAIDs over time may cause nephritis and hyperkalcaemia. Prolonged analgesic abuse over a period of years is associated with papillary necrosis and chronic renal failure.
Why should be not prescribe aspirin to children under age 16?
It can cause Reye’s syndrome.
What is Reye’s syndrome?
Very serious up to 50% mortality. Fatty degenerative process in liver (and kidney but to a lesser extent). There is a profound swelling in the brain
Clinically- nausea, vomiting and lethargy initially then later seizures/coma.
What is encepalophy?
“Encephalopathy” means damage or disease that affects the brain. It happens when there’s been a change in the way your brain works or a change in your body that affects your brain. Those changes lead to an altered mental state, leaving you confused and not acting like you usually do.
What is miosis?
Excessive constriction of the pupil of the eye.
