NSAIDs Flashcards
What are some commonly used NSAIDs in small animals
Meloxicam,
Carprofen,
Robenacoxib,
Firocoxib
Cimicoxib
Mavacoxib
Grapiprant
What are commonly used NSAIDs in equine
Phenylbutazone (suxibuzone)
Flunixin meglumine
Meloxicam
What are commonly used NSAIDs in farm animals
Meloxicam,
Ketoprofen,
Carprofen
How does an injury cause pain?
- Injury occurs:
- Disruption of cell membrane - Phospholipid metabolism:
- Phospholipids in disrupted membrane metabolised by phospholipase A₂, releasing arachidonic acid - Arachidonic acid pathways:
- Processed by Cyclo-oxygenase 1 (COX-1) or Cyclo-oxygenase 2 (COX-2) enzymes - Prostaglandin production:
- COX enzymes convert arachidonic acid into prostaglandins, thromboxanes, & other prostanoids. - Pain and oedema:
- Prostaglandins sensitise nociceptive neurons, causing pain
- Also promote vasodilation & increased vascular permeability, leading to oedema
What are the effects of NSAIDs
Anti-inflammatory effect
Analgesic effect
Anti-pyretic effect
What do NSAIDs inhibit
Inhibit COX enzymes & thus prostanoid synthesis in inflammatory cells
Inhibition of COX2 isoform is crucial for their therapeutic action
Describe the anti-inflammatory action of NSAIDs
Decrease in PGE2 & PGI reduces vasodilation & indirectly oedema
Describe the analgesic effect of NSAIDs
Decreased PG generation –> reduced sensation of nociceptive nerve ending to inflammatory mediators (e.g. bradykinin)
Relief of headache probs due to decreased PG-mediated vasodilation
Describe the anti-pyretic effect of NSAIDs
interleukin 1 releases PG in CNS where they elevate hypothalamic set point for temperature control thus causing fever
NSAIDs prevent this
What is the difference in COX inhibition between older NSAIDs and “coxibs”?
Older NSAIDs (e.g., aspirin, phenylbutazone) are non-selective COX inhibitors
“Coxibs” (e.g., robenacoxib, firocoxib) are highly COX-2 selective, reducing side effects associated with COX-1 inhibition (e.g., gastric damage).
what are the pharmokinetic properties of NSAIDs?
Weak acids: Well absorbed orally within 2–3 hours
- food can impair absorption of some
High plasma protein binding: Up to 99%.
Metabolized in the liver: Inactive metabolites excreted in urine or bile (except mavacoxib, excreted unchanged in bile).
What are the different classes of NSAIDs
Salicylates
Phenylbutazone
Ketoprofen
Carprofen
Flunixin
Oxicam derivative
Coxib
Describe Salicylates
non-selective
irreversible interaction with COX
mild to moderate pain
e.g. aspirin
Describe Phenylbutazone
non-selective
management of mild-moderate pain & inflammation
Main metabolite has similar properties
Low therapeutic index
half-life: 3-6h
don’t use in cats
Describe Ketoprofen
non-selective
acute pain & chronic pain from osteoarthritis
alleviation of inflammation & pain associated with MSK & GI disorders
not licensed for peri-operative indication
Describe Carprofen
COX2 preferential
post-operative pain & inflammation
Reduction of chronic inflammation
Reduce pain associated with acute infectious respiratory disease & mastitis
Describe Flunixin
alleviation of inflammation & pain associated with MSK, respiratory & GI disorders
Describe Oxicam derivative
CO2 selective
Alleviation of inflammation & pain in chronic MSK disorders & post-operative pain
e.g. Meloxicam & Piroxicam
Describe Coxib
highly COX2 selective
pain & inflammation associated with osteoarthritis & peri-operative
e.g. Robenacoxib, Firocoxib, Mavacoxib, Cimicoxib
What are the general contraindications of NSAID use
Do not combine different NSAIDs or administer them within 24 hours of each other.
Avoid use in animals with:
- Cardiac, hepatic, or renal disease.
- GI ulceration or bleeding risk.
Avoid concurrent use with nephrotoxic drugs.
What are the common side effects of NSAIDs
Gastrointestinal: Ulceration & bleeding (due to suppressed gastroprotective prostaglandins in gastric mucosa)
Cardiovascular: Hypertension and potential heart issues
Renal: Reversible renal insufficiency in compromised animals
Bronchospasm: In aspirin-sensitive animals.
What is Grapiprant & how does it differ from traditional NSAIDs
Grapiprant is a selective EP4 receptor antagonist, targeting PGE2-induced nociception without inhibiting COX enzymes
It has reduced risk of GI, renal & cardiovascular side effects compared to COX inhibitors
Rapid absorption
Primarily excreted via faeces but also renal
Use with caution in dogs suffering from pre-existing liver, cardiovascular, renal or GI disease
