Non-opioid Analgesics Flashcards
Amine autocoids
histamine, serotonin
Lipid derived autocoids
prostaglandins, leukotrienes
Peptide hormones
bradykinin, angiotensin
Autocoids
amine, lipid-derived, peptide hormones and cytokines
NSAIDs
Salicylates, arylpropionic acids, arylacetic acids, enolic acids
Salicylates
aspirin
Arylpropionic acids
Ibuprofen, naproxen
Arylacetic acids
Indomethacin, diclofenac, ketorolac, etodolac
Enolic acids
Piroxicam (Feldene) and meloxicam (mobic)
p-Aminophenols
acetaminophen
Therapeutic applications of NSAIDs
analgesic, antipyretic, anti-inflammatory
Three phases of inflammation
Acute (vasodilation, increased permeability)
Subacute (infiltration)
Chronic (proliferation)
Mediators that recruit inflammatory cells
Arachidonic acid metabolites, prostaglandins, thromboxanes, leukotrienes, and cytokines
What kind of inhibitors are NSAIDs?
COX inhibitors
Inhibition of COX-1 leads to
a reduction in thromboxanes, causing reduced platelet aggregation - thus NSAIDs also function as a blood thinner
COX1 enzymes, prostaglandins and prostacyclins serve what kind of role in the GI tract?
a protective role
COX-1 constitutively expressed in
platelets, stomach and kidney
PGE2 and PGI2 are protective in
stomach; inhibit acid secretion, promote mucus secretion
Inhibition of PGE2 and PGI2 can lead to
stomach ulcers
What do prostacyclins do?
vasodilation and reduce platelet aggregation
What do thromboxins do?
synthesis induces platelet aggregation, vasoconstriction, and inhibitor functions as a blood thinner
COX-2 constitutively expressed in
brain and spinal cord
When is COX-2 induced?
induced in the setting of inflammation and induced by cytokines and inflammatory mediators
MOA of aspirin
irreversibly inhibits COX1/2 by acetylation; modifies COX2 activity; duration of effect corresponds to time required for new protein synthesis
MOA of other NSAIDs (besides aspirin)
competitive (reversible) inhibitors of COX 1/2; some arylacetic acids also inhibit leukotriene synthesis, contributing to anti-inflammatory effects
Absorption of salicylates
rapidly absorbed from stomach and jejunum
aspirin mainly absorbed in jejunum
passive diffusion of free acid
delayed by presence of food
Distribution of salicylates
throughout most tissues and fluids, readily crosses placenta, competes with many drugs for protein binding sites
Metabolism and excretion of salicylates
Active secretion and passive reabsorption in renal tubule, increased excretion with increased urinary pH
Absorption of non-salicylate NSAIDs
well absorbed from GI tract
Metabolism of non-salicylate NSAIDs
Little first pass metabolism; multiple routes of metabolism; therapeutic effect poorly related to plasma levels
Excretion of non-salicylate NSAIDs
drugs and metabolites excreted primarily as conjugates; active secretion of parent drug in renal tubule
Aspirin’s main use is for
anti-coagulation
MOA of ibuprofen and naproxen
potent reversible COX inhibitors
Safest to use in CAD
Naproxen