Nagelhout video's: non-opioid agonists Flashcards
What is paracetamol
Acetaminophen
(Paracetamol is the active ingredient in acetaminophen)
T/F: Aspirin, Acetaminophen, and NSAIDs are all antipyretics, analgesics, and anti inflammatory
False
-All are antipyretic and analgesics but acetaminophen is NOT anti-inflammatory
How does Decadron produce analgesia?
by inhibiting peripheral phospholipase
>decreases the pain-producing substances from the cyclooxygenase and lipoxygenase pathways (prostaglandins- associated with inflammation and pain)
-also reduces serotonin which is implicated in the pain response
-decreases tryptophan (precursor to serotonin)
-decreases serotonin turnover in the brain
-reduces serotonin release in the gut
-inhibits the NTS which has outflow tracts to the gut via the vagus nerve (serotonin receptors)
Primary MOA of NSAIDs
block COX
(cyclooxygenase)
When you turnover cells in the body (RBCs, WBCs, platelets), prior to eliminating the dead cell membrane of these cells through the urine, your body extracts some chemicals from these dead cell membranes so it doesn’t have to make new ones (recycles substances) is what?
Arachidonic acid
What is arachidonic acid?
What enzyme acts upon it?
An acid compound found in cell membranes that the body extracts and recycles after the cell dies
COX acts upon it (cyclooxygenase)
Which COX enzyme is constitutive vs inducible and what does that mean?
Cox-1 is constitutive which means it’s found in the body all the time
Cox-2 is inducible - meaning it’s usually latent in the body
*until tissue is injured, then COX-2 is released
Ie) so if you sprain your ankle, your body is going to activate/release COX-2 to help break down arachidonic acid to release more prostaglandins and thromboxanes to help stabilize the cell membranes and aggregate platelets
What does COX-1 break down?
Arachidonic acid to prostaglandins and Thromboxanes (TXA2)
Prostaglandins put a protective coating over the gastric mucosa
TXA2 preserves endothelial function (support cell membrane integrity, support platelet aggregation)
What is the specific COX-inhibitor that remains on the market today
Celebrex
What’s Reyes Syndrome?
-fatal condition caused by giving aspirin to children
MOA of NSAIDs
They block the synthesis of prostaglandins by inhibiting COX-1 & COX-2
Side effects of NSAIDS (4)
- Block platelet aggregation
>increased bleeding - Renal Dysfunction
>with long-term use
(prostaglandins are necessary to maintain normal renal function) - GI hemorrhage/ulcers
>with long-term use - Slow bone healing + block osteoneogenisis
Do NSAIDs inhibit platelets competitively or noncompetitively?
When would you be concerned about potential bleeding…if your patient took something when?
Competitively - once you stop taking NSAIDs, platelet function resumes (avoid 24 hours before surgery)
T/F: Tylenol has anti-inflammatory properties
False
T/F: Tylenol’s MOA includes reducing prostaglandins by blocking COX-1 and COX-2
True (but poorly understood bc it doesn’t reduce inflammation)
The mechanism by which NSAIDs lead to GI bleeding
by inhibition of COX-1 which helps protect the endothelial lining of the GI tract
Whether to take Tylenol or Advil?
Headache/Fever- prob Tylenol (less side effects)
Anything with tissue damage or swelling - NSAD
Explain the metabolism of Acetaminophen
- what’s it conjugated with
-what’s it broken down by, to what?
-what happens to that
It’s conjugated with glucuronide + sulfate
+ broken down by CYP2E1 to NAPQI*
N-Acetyl-p-benzo-quinone-imine
- small amounts can be detoxified by glutathione in the liver into nontoxic metabolites
if you produce more NAPQI than the glutathione can detoxify, that’s when you get liver damage
Treatment of Tyelonol OD
Acetylcysteine
>replenishes glutathione (enzyme that helps detoxify the toxic metabolite of NAPQI)
What lab test would you do to assess for aspirin levels?
bleeding time
They say people can safely continue taking their aspirin throughout the peri-op period (they are on it for a reason and the risk of stopping it prob outweighs the benefit of less bleeding)
What are 3 circumstances you would want the patient to stop their aspirin 7-10 days prior to surgery?
Risk for large amount of bleeding into closed spaces
- Eye surgery (closed space- any kind of bleeding will increase IOP and be bad)
- Brain Surgery
- Prostate Surgery (super vascular)
Should you give Toradol to an asthmatic?
Probably not- only if you ask them before hand if they take NSAIDs or not
(some people have aspirin-induced asthma and there can be a cross-allergy amongst the other NSAIDS)
TCAs can be given for chronic pain management, how do they work?
block reuptake of serotonin and NE
(I thought serotonin increased pain? Maybe it has something to do with acute vs chronic pathway)
