COX Inhibitors Drugs 5-6 Flashcards
5-6 questions
COX: Cyclo-oxygenase
-an enzyme that converts arachidonic acid into prostaglandins
-good for pain and inflammation
-good for protection of gastric mucosa
-others: PLT aggregation, renal vasodilate, uterus contraction
-act locally, NO affect distant sites from them
COX 1(good)
-protect gastric mucosa
-support renal blood flow
-promote PLT aggregation
COX 1 Inhibitor
(inhibiting the good) = now BAD
-protect against MI and CVA: only benefit (due to no PLT aggregation)
-reduces PLT aggregation: bleeding tendencies
-gastric erosion
-renal impairment
COX 2 (bad)
-mediates inflammation, fever
-sensitizes receptors to pain stimuli
(produced at sites of tissue of injury)
-vasodilate blood vessels, kidneys
-can contribute to colon cancer
COX 2 Inhibitor
(inhibit the bad = now GOOD)
-suppress inflammation
-alleviates pain
-reduces fever
-protects against colon cancer
-renal impairment
-promotes MI and CVA: suppress vasodilation
2 classifications
With anti-inflammatory properties
-1st gen NSAIDS: inhibit both COX 1 and COX 2
ex: Aspirin, Ibuprofen, Naproxen
-2nd gen NSAIDS: inhibit only COX 2 (newer)
-ex: Celecoxib
Without anti-inflammatory properties
-Acetaminophen: Tylenol
First gen NSAIDS
(Aspirin, Ibuprofen, Naproxen)
-inhibit BOTH COX 1 and COX 2
-irreversible nonselective COX inhibitor
-reduce fever, inflammation, pain (due to COX 2i)
-protect against MI and CVA (due to COX 1i)
-low dose selectively inhibit COX 1 –> selective antiPLT
NSAIDS: Aspirin pharmacokinetics and uses
-PO (give with food/full glass water) or suppository
-rapidly converted in liver –> salicyclic acid
-excreted by kidneys (raise pH to 8 –> increase excretion)
+ dose reduce if renal impaired
-high salicyclate levels can lead to toxicity (salicyclism)
-good for inflammation, fever, pain, dysmenorrhea (block prostaglandins –> reduce cramps), suppress PLT aggregation, prevent cancer
=BEST for MI and stroke
NSAIDS: Aspirin adverse
-GI: distress, heartburn, nausea –> destroys GI if long term use (use with PPIs or H2RAs)
-bleeding: decrease PLT aggregation:
-renal impairment
-salicylism: headache, tinnitus, sweating, dizzy
-reyes syndrome: salicyclism for children (<18y/o)
-hypersensitivity: like SJS (rare)
NSAIDS: Aspirin contraindications
DONT give:
-PUD
-bleeding disorders: monitor PLT, PT, INR, h/h
-hypersensitivity to ASA and NSAIDS
Precautions
-children!!!
-pregnant: ALL except tylenol worry abt in preg excessive bleed/hemorrhage
-hepatic or alcohol abuse/renal dysfunction
-asthma
-discontinue 7-10 days before surgery: inhibit lifespan of a PLT
Aspirin (acetylsalicylic acid) poisoning
-lethal in children (if child has flu –> STAY away from ASA)
s/s:
-initially: respiratory alkalosis w/ resp depression
-acidosis and hyperthermia
-sweating, dehydration, electrolytes imbalance
-stupor –> coma
-NO antidote –> Supportive care (IVFs with HCO3, gastric lavage, activated charcoal if theyre awake)
+ may place NG tube
Non-Aspirin 1st gen NSAIDS
(Ibuprofen, Naproxen, Ketorolac)
-fewer GI and hemorrhagic effects
-nonselective REVERSIBLE COX inhibitors
(NOT best for MI or stroke bc no antiPLT aggregation)
-only good for fever, inflammation, pain (no use for MI)
-generally same adverse and cross sesnsitivty to ASA
Ibuprofen (Motrin, Advil)
-fever, pain, cramps (dysmenorrhea)
-less gastric bleeding, less PLT aggregation inhibition
-PO or IV
Ketorolac (Toradol)
-powerul analgesia with minimal anti-inflammatory properties
-short term use only
-IV: use no more than 2 days
-PO: no more than 5 days –> risk more bleed and kidney impair
Naproxen
-prolonged half-life –> admin less frequent
