Opoids, NSAIDS, Acetaminophen Flashcards
What receptors do opioids act on?
Mu, Kappa, Delta
What are mu receptors for?
kind of everything
what are Kappa receptors for?
sleepiness, pain relief, slowing down the gut
What are delta receptors for?
we don’t really know
Effects of Opioids
Analgesia, respiratory depression, sedation, euphoria, physical dependence, decreased gut motility
What is the most dangerous effect of Opioids?
respiratory depression
How do pure agonists work
bind to activate receptors
How do pure antagonists work
bind to receptors and block them
what is the main cause of death from opoids?
decreases the sensitivity of respiratory center in the brain causing a build up of CO2
What can increase respiratory depression?
when mixed with other cns depressants ie: alcohol, benzos, muscle relaxers, gabapentin
You will build a tolerance to all but what 2 things?
constipation, miosis
Physical dependence
happens to anyone using opioids for 2 or more weeks
what is the general rule for cross tolerance?
reduce equanlgesic dose by 25-50%
First signs of with drawl
yawning, rhinorrea, sweating
progressing withdrawl
anorexia, irritability, tremor
Severe withdrawl symptoms,
violent sneezing, cramps, NV, weakness, diarrhea, muscle spasms
Morphine drug class
Pure agonist
What route is the worst for morphine and why?
Oral; because absorption varies
Who needs special dosing with morphine?
older pts need doses decreased by 33%; can accumulate with low renal function
Other agonists related to morphine (4)
Codeine, Hydromorphone, Hydrocodone, Oxycodone
What is essential for codeine?
CYP2D6
what is CYP2D6?
enzyme that breaks down fat soluble drugs in the liver
Why does codeine work?
because 15% of it gets turned into morphine
Tramadol
half opioid agonist, half antidepressant
What receptor does Tramadol bind to?
Mu receptor
What does tramadol block?
the reuptake of serotonin and epinephrine
who would tramadol benefit
People experiencing nerve pain
Mixed agonist-antagonist
lower risk for respiratory depression and abuse
what is an analgesic ceiling
they can only provide so much relief
what drug class has an analgesic ceiling?
mixed agonist-antagonist
Buprenophrine drug class
mixed
what side effects are to mixed aginist-antagonists?
psychotomimetic- hallucinations and dysphoria
what can mixed drug class cause?
opioid withdrawl
Antagonists (central acting)
OD and abuse deterrent- Naloxone
Antagonists (peripheral)
treatment of opioid related constipation: methylnaltrexone
NSAIDS
inhibit central and peripheral prostaglandin synthesis
what stimulates COX 2
process of injury
What NSAIDS are non specific to Cox 1 or 2
ibuprofen, meloxicam, naproxen, diclofenac
What NSAID is specific to COX2
celoxib
What is the highest risk of NSAID use?
GI bleeding and ulcers
Why do NSAIDS cause gi bleeds?
because they inhibit prostaglandins so the stomach lining isnt protective against the acid
What is decreased especially if someone is dehydrated or taking an ace inhibitor?
Renal function
Why do NSAIDS lower platelet fxn?
makes them less able to stick together, easy bruising and bleeding
Cardiac toxicity (NSAID)
only related to COX2
Who is at high risk for GI bleeds with NSAID use
people with a history, on aspirin, warfarin, steroids, over the age of 65
Treatment for GI bleeds with NSAID use
concurrent PPI use, change to celoxib
Ketorolac
max of 5 day use in all forms, has dose adjustments for people over the age of 65 and that weigh less than 50 kg
Contraindications of Ketorolac
prior or active ulcer, advanced renal disease, high bleeding risk, concurrent aspirin use, NSAID or probenecid (gout drug)
Acetaminophen
inhibits central prostaglandin synthesis- does not work outside the brain
what does acetaminophen not help with
swelling
what toxic substance does acetaminophen get turned into when metabolized by the liver?
NAPQI
What is acetaminophen the biggest cause of
acute liver failure
