Allergy, Inflammation and Pain Flashcards
What are the functions and clinical relevances of COX1 and COX2?
COX1 - many roles, widely expressed, responsible for the side effects of NSAIDs.
COX2 - upregulated in inflammation, therapeutic benefits of NSAIDs by inhibiting this enzyme.
Name the compound created from arachidonic acid by COX1?
What is this molecule then converted into?
PGH2
Then converted into: Thromboxane A2 (platelets) Prostacyclin (PGI2)
Mechanism of action of ibuprofen.
Competitive inhibitor of COX1
Mechanism of aspirin.
Irreversible inhibition of COX1 via acetylation
What are the main side effects associated with inhibiting COX1 and COX2?
COX1 - GI risk
COX2 - cardiovascular risk
Mechanism of celecoxib?
Side effects?
Specific COX2 inhibitor.
Side effects are increased risk of stroke and MI as it dysregulates fluid balance in the kidney.
Functions of PGE2?
Fever, cytoprotection and degranulation of mast cells
Function of PGD2?
Involved in the nervous system, induction of sleep, inhibition of platelet aggregation, vasodilation
Function of PGF2a?
Uterine contraction and pain associated with periods. Bronchoconstriction.
How do prostaglandins mediate pain?
They cannot do it directly.
They increase the affinity and responsiveness of cells to kinins and serotonin which mediates pain.
Which drugs are used for migraine prophylaxis?
Antihistamines
B-antagonist
TCAs
5-HT ANTAGONIST.
Name a 5-HT agonist?
Give its therapeutic actions.
Triptans e.g. sumatriptan.
Constricts large blood vessels, inhibits trigemical nerve, desensitises sensory nerves.
Which drug classes are used for acute relief of migraines?
NSAIDs
5-HT AGONISTS
Paracetamol
Antiemetics
Name a serotonin antagonist.
Pizotifin
