NSAIDs Flashcards
What are NSAIDs generally used for
To treat inflammation, pain and fever
What causes inflammation pain and fever and how does NSAIDs stop them
The increase in production of prostaglandins leads to those symptoms, so NSAIDs help decrease the production of prostaglandins
What’s the mechanism of action of NSAIDs
They work by inhibiting COX enzymes which produce prostaglandins from arachidonic acid, so by inhibiting COX we inhibit the production of prostaglandins
What’s an example of an irreversible cox inhibitor
Aspirin
What’s a selective COX 2 inhibitor
Celecoxib
How long before a surgery should aspirin be discontinued
1 week earlier
Aspirin mode of administration
Taken orally
What effect does aspirin have on COX
It inhibits both COX 1 and 2 irreversibly
How does aspirin inhibit both COX 1
In the blood stream it irreversibly inhibits COX1 in platelets by ACETYLATION decreaseing the production of thromboxane A2-> it’s a platelet activator making aspirin a useful anti platelet medication
How does aspirin inhibit both COX 2
In the liver aspirin get metabolised in to salicylate which has no anti-platelet activity but has anti inflammatory activity
- salicylate works by inhibiting COX 2 -> decrease in prostaglandins production decreasing inflammation, pain and fever
Aspirin anti inflammatory activity is achieved at which does
4-6g/day
Aspirin antipyretic and analgesic activity is achieved at which does
2-3G/day
Aspirin antiplatelet activity is achieved at which does
75mg-150mg/day
What’s aspirins lethal dose
20-30g
Aspirin indications
Analgesia, fever, inhibition of platelet aggregation, rheumatoid arthritis and other rheumatoid diseases
What’s the effect of aspirin of Alzheimer’s and colon cancer
Decrease the incidence
Aspirin adverse effects
GI system, Hepatitis, Reyes syndrome, bleeding, aspirin asthma hypersensitivity asthma
What is salicylism
Acid base disturbances, tinnitus and deafness
What’s the treatmeant of salicylism
Activated charcoal, alkalinity urine and electrolyte replacement
What irreversibly inhibits Cox 1 and 2
Non selective COX inhibitors
Non selective COX inhibitors derived from proprionic acid derivatives
Ibuprofen, naproxen
Non selective COX inhibitors from acetic derivatives
Indomethacin and sulindac
Non selective COX inhibitors from heterosexual acetic acid derivatives
Do life ax and ketorelac
Why shouldn’t we give non selective Cox inhibitors with aspirin
They compete with aspirin on COX1 receptors decreasing the anti platelet activity since they are reversible
What are the indications of Non selective COX inhibitors
Since they inhibit COX 2 they have the same indications as aspirin
Which NSAIDs should be given to patients with information during a gout attack
Ibuprofen, naproxen and indomethacin
Why is aspirin contraindicated in gout attacks
Because it competes with uric acid excretion in the kidney
Ibuprofen right dosing
400 mg
Which NSAID is used for tooth ache
Ibuprofen
Which NSAID causes the closure of ductus arteriosus
Ibuprofen —> most correct
indomethacin —> can be correct
Which NSAID is used to treat severe pain after surgery
Ketorolac
Which NSAID is used for long term treatment of rheumatoid arthritis osteoarthritis and ankylosing spondylitis
Diclofenac
What’s the only COX 2 selective inhibitor and what are its contraindications
Celecoxib and is contraindicated in people with increased risk of thrombosis and CVD
Can celecoxib be used with aspirin and why
Yes as it only inhibits COX2 and won’t compete with aspirin over COX 1
Why are there contraindications to Celecoxib
Since it doesn’t have an effect on COX 1 they can increase the ability of blood to clot —> increase the risk of heart attack and stroke
How do NSAIDs cause GI symptoms
By inhibiting COX 1 reducing the products of cytoprotective prostaglandins leading to ulcers of gastritis
What’s the order of severity of GI symptoms with different drugs
Aspirin> Non selective COX inhibitors > Celecoxib
What is samters triad
People with asthma and nasal polyps are more likely to experience NSAIDs hypersensitivity reactions
How to prevent GI upset with NSAIDs
Take them with food
Why can’t aspirin be taken with antaacids
Reduces absorption
Why can’t aspirin be taken with heparin
Can lead to haemorrhage
What are the contraindications of aspirin
Hyper sensitivity to salicylate and bleeding disorders
What is another name for paracetamol
Acetaminophen
What is acetaminophen used for
Antipyretic and analgesic drug
Does acetaminophen have any anti inflammatory activity
Little to no anti inflammatory activity
What acetaminophen lethal does and lethal does in alcoholics
12 grams
2.7 grams
What’s the maximal single does of acetaminophen
650 mg
What are the adverse effects of acetaminophen
Hepatotoxicity
What’s the antidote for acetaminophen
N-acetylcysteine, activated charcoal and fluids
What do we give and don’t give to febrile children
We don’t give aspirin to febrile children
We administer paracetamol 10-15 mg/kg or ibuprofen 7-10mg/kg
What is the Toxic by product of acetaminophen
NAPQI or N acetyl p benzoquinoneamine
Naproxine is contraindicated
People with CVD
