NSAIDS Flashcards
What are NSAIDs?
Non Steroidal Anti Inflammatory Drugs
What do NSAIDs do?
Analgesic (anti-pain), antipyretic (anti-fever), anti-inflammatory (except acetaminophen)
With a ceiling effect
How do NSAIDs work?
Stop the formation of prostaglandins by blocking the COX 1,2,3 enzymes
What does cyclo-oxygenase-1 do?
Found in many cell types. Many critical functions like maintaining stomach lining
Not involved in fever
What does cyclo-oxygenase 2 do?
This form is induced in immune cells
Responsible for pain, inflammation and fever
What are the 3 phases of inflammation?
Acute transient phases (local vasodilation, increased capillary permeability)
Delayed subacute phase (infiltration of leukocytes and phagocytes)
Chronic proliferative phase (tissue degeneration and fibrosis)
What do prostaglandins do?
Released following cell damage, cause local inflammation, increased blood flow, severe pain, increase hypothalamic set point, stimulate local pain fibres
What are NSAIDs most useful for?
Uterine cramping, joint swelling
Would be more superior than opioids but take too long to work
What are the other effects of prostaglandins?
Platelet aggregation formation, modulate stomach acidity and mucous lining, uterine contraction
What are the 2 mechanisms of action of ASA?
Irreversibly acetylates COX enzymes (unlike the other NSAIDs) with the effect lasting as long as it takes to replace the enzymes
Not dependent on clearance
How can caffeine be used to help NSAIDs?
Will increase the effect of all non-opioid analgesics to give a co-analgesic effect.
60-120 mg (cup of coffee)
What happens in caffeine withdrawal?
Sudden onset of a headache
What can cause salicylate overdose?
Pepto bismol (bismuth salicylate) and methylsalicylate (oil of wintergreen-4 ml)
What are some symptoms of salicylate overdose?
Tinntus
Increase in metabolic rate due to interference with oxidative metabolism (hyperventilation, metabolic acidosis, severe hypoglycemia)
What are the immediate dangers of a salicylate overdose?
Hyperthermia, dehydration and hypoglycemia
What is the treatment of salicylate overdose?
Parenteral fluids and glucose (always, immediately), parenteral sodium bicarbonate, acetazolamide, activated charcoal (only within 2 hours), polyelectrolyte lavage (for modified release salicylate) or hemodialysis (severe)
What are the salycilates?
Methylsalicylate, bismuth salicylate, aspirin
Which NSAIDs are in the proprionic acid class?
Ibuprofen (less GI effects), Naproxen (twice daily dosing)
What is diclofenac?
A prescription only high potency NSAID with a higher GI bleed risk
Used for inflammatory pain (arthritis, post operative swelling, gout), sometimes endometriosis
Gel for muscular/joint pain
What is indomethacin used for?
Specifically for gout pain and swelling
Why are there GI side effects with NSAIDs?
Prostaglandins are made by the gastric mucosa and surpress acid production, increase gastric blood flow and increase secretion of mucin.
Non selective COX inhibitors inhibit COX-1, increasing acid production and decreasing mucous protection.
What is misoprostol? What is it used for?
A prostaglandin analog (similar structure and function) that is given with ASA to supply the stomach with the prostaglandin effect lost with non-selective COX inhibitors
What are some adverse effects from NSAIDs?
Reye’s Syndrome (ASA in children with viral infections and genetic predisposition)
What are some drug interactions with NSAIDs?
Inhibits alcohol, warfarin and rofecoxib
In what patients should NSAID use be cautioned?
Hypertension, angina, (increase in circulating volume) bleeding disorders
What are some example of COX 2 selective inhibitors?
Vioxx and Bextra (pulled, heart attack risk)
Celebrex has black box warning
How are the analgesic effects of acteaminophen different from other NSAIDs?
Acts centrally, thus no ceiling effect
How does acetaminophen overdose occur?
A highly reactive metabolite of acetaminophen depletes GSH (antioxidant) in the liver causing damage to liver indirectly from loss of anti-oxidant and directly from highly reactive intermediate.
What are the signs and symptoms of acetaminophen overdose?
Severely elevated serum transaminase levels, hepatic encephalopathy and jaundice
What is the best way to treat a headache?
Highest dose of NSAID, cup of coffee and glass of cold water.
