NSAIDs Flashcards
common mechanisms of NSAIDs
inhibit COX, which blocks formation of prostaglandins, thromboxane A2
function of PGI2
vasodilation, inhibits platelet aggregation
function of TXA2
vasoconstriction, platelet aggregation
function of PGI2 and PGE2
decrease gastric acid secretion; lower pain threshold
function of PGE2 and PGF2
contract uterine smooth muscle
major sites of COX1 expression (which could result in toxicity of NSAIDs)
platelets, kidneys, blood vessels, stomach
when is COX2 expressed vs when COX1 is expressed?
COX2 expression is induced during inflammation; COX1 expression on nearly every cell
how do NSAIDs produce analgesia?
by blocking production of prostaglandins, which lower pain threshold. effective against mild to moderate dull, aching pain; act synergistically with opiates
how do NSAIDs produce anti-inflammatory effects?
reduce edema by bocking PGE2, PGI2; reduce pain; high concs of NSAIDs reduce neutrophil migration
how are NSAIDs antipyretic?
PGE2 alters body temp set point, so it blocks production of PGE2
clinical uses of NSAIDs
pain, primary dysmenorrhea, joint inflammation, fever
why is GI distress, damage, bleeding a common side effect of NSAIDs?
PGs help secrete mucous, bicardonate, H+ to protect the stomach from acid. NSAIDs decrease PG levels, so overtime the stomach acid causes pain and bleeding ulcers
common renal side effects of NSAIDs
fluid retention (increased AHD activity), decreased sodium excretion, decrease GFR, interstitial nephritis
common vascular side effects of NSAIDs
prolonged bleeding time and hypertension in sensitive patients.
contraindications of NSAIDs
px with reduced clotting factors, where TXA2 plays an important role in clotting; px with atheroschlerosis, where PGI2 plays an important role in opposing constriction (because NSAIDs increase bleeding and blood pressure)
salicylate NSAIDs
aspirin, diflunisal
acetic acid derivative NSAIDs
indomethacin, ketorolac