Lecture 15 - NSAIDs Flashcards
What are the different types of prostanoids?
Prostaglandins, prostacyclin and thromboxanes
Why type of production are prsotanoids done under?
Produced locally and on demand
What is the name of the prostanoid PGI2?
Prostacyclin
What is therapeutic benefit of prescribing NSAIDs?
They inhibit the down stream products of arachidonic acid
What types of acid is arachidonic acid mainly derived from?
Dietary linoleum acid
What are the half lives of prostanoids like?
Short half-life
What is the normal function of prostacyclin (PGI2)?
Inhibts platetl aggregation since PGI2 binds to. Platelet. Receptors increasing cAMP levels in platetls
How do Prostacylins (PGI2) and TXA2 (Thromboxane A2) typically affect the CVS?
PGI2 = cytoprotective ofCVS
TXA2 = bad for CVS
What does Thromboxane A2 do ?
Leads to platelet aggregation
Why is PGE2 and prostacyclin (PGI2) improtant to the GI tract?
PGE2 contributes to Regualtion of acid secretion in parietal cell
PGI2 contributes to maintenance of blood flow and mucosal repair
How are prostanoids signalled?
They have many receptors and differential expression in tissues and repsonse (Many GPCR)
Have fine local control
What substances often enhance the action of prostanoids?
Local autocoids like Bradykinin and HIstamine
What 2 types of prostanoids do we need to carefully balance and why?
PGI2 (prostacyclin) and Thromboxane A2
they have a posing vascular effects
Fine balance between haemodynamic and thrombogenic control
What do we increase risk of. If imbalance in TXA2 and PGI2?
Hypertension
MI
Stroke
What are the benefits of the Mediterranean diet?
More conversion of Thromboxane A3 to PGI3 which is a better prsotnatooid
What do NSAIDs inhibit?
Cyclooxygenase enzymes (COX enzymes)
Where are COX1 and COX2 located?
COX1 = across most tissues
COX2 = indibcle mostly in chronic inflammation in brain, kidney and bone
What are the main effects NSAIDs do?
Analgesia
Anti-inflammatory
What is the mechanism of action of NSAIDs?
What do they compete with?
Inhibition of COX enzymes leading to reduced prostaglandins (prostacylins and Thromboxane synthesis)
Compete with arachidonic acid for hydrophobic site of COX enzymes
What are some common NSAIDs?
Naproxen
Ibuprofen
Celecoxib
How do NSAIDs act as analgesics?
Reduces peripheral pain fibre sensitivity by BLockinng PGE2 (Prostaglandins)
What is the pathway for NSAIDs acting as analgesics?
Reduced PGE2 (prostaglandin) synthesis in dorsal horn of cord
Dec neurotransmitter release
Reduced excitability of neurons in pain relay pathway
How do NSAIDs act as antiflammtories and act against oedema?
Prostaglandins lead to vasodilation and oedema (NSAIDs reduce prostaglandins) so less vasodilation so less increased capillary permeability and less local swelling