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Year 2 Pharmacology > NSAIDs > Flashcards

Flashcards in NSAIDs Deck (24)
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1
Q

What drugs can be used to treat inflammatory disorders?

A
Non-steroidal anti-inflammatories
Glucocorticoids
Anticytokines
Immunosuppressants 
Antihistamines
2
Q

What are prostanoids?

A

Prostoglandins and thromboxanes

3
Q

Explain the mechanism of action of NSAIDs

A

Prostanoids are synthesised via the metabolism of arachidonic acid.
This involves the enzyme cyclo-oxegenase (COX)
NSAIDs are COX inhibitors which suppress prostanoid synthesis

4
Q

What is the full name of COX enzyme?

A

Cyclo-oxygenase

5
Q

Where are Cox 1 and 2 found and what is their action?

A

Cox 1- present in most cells, produces prostanoids that act as homeostatic regulators (gastric acid secretion)
Cox 2- not normally present (CNS and renal exempt) but is strongly induced by inflammatory stimuli (IL-1)

6
Q

Name 5 NSAIDs?

A
Asprin
Ibuprofen
Phenylbutazone
Paracetamol
Meloxicam 
Over 50 used in vet med
7
Q

How can NSAIDs be administered?

A

Oral, injectable and transdermal gels

8
Q

In what species should paracetamol not be used?

A

Cats- toxic

9
Q

How is NSAIDs absorbed, distributed and eliminated?

A

Absorbed- weak acids, readily absorbed in GI tract, injectable usually alkaline (painful)
Distribution- Bound by albumin
Elimination- Hepatic phase I and II metabolism, conjugate metabolites are excreted in urine/faeces

10
Q

What NSAID can be used in companion animals but not food producing animals and why?

A

Phenylbutazone- can cause aplastic anaemia in humans and has very long half life

11
Q

What are the main examples of use of NSAIDs?

A

Anti-inflammatory action- decrease prostaglandin E2 and prostacyclin reduces vasodilation and indirectly oedema
Analgesia- decreased prostaglandin means less sensitisation of nociceptive nerve endings
Antipyretic- Pyrexi is caused by the release of prostaglandins in the CNS where they elevate the hypothalamic set point and cause fever- NSAIDs prevent the release of prostaglandins in the CNS

12
Q

What are the adverse effects of NSAIDs?

A

GI ulceration and erosion
Renal damage- don’t use on hypotensive and hypovolaemic animals
Hepatotoxicity
Circulatory disturbances

13
Q

What are the contra-indications of NSAIDs?

A

Pregnancy
Use with other NSAIDs or glucocorticoids
Underlying renal, liver and cardiac impairment

14
Q

What species is phenylbutazone used for?

A

Dogs and Horses - very long half life, 99% bound

15
Q

What is meloxicam used for and what are its features?

A

Preferential COX 2 inhibitor
97% bound to albumin
Used in acute/chronic pain and inflammation
Species variation in half life- long in cats, short in horses

16
Q

What are the effects of paracetamol and what species is it licensed in?

A

Antipyretic and analgesic action
Only acts in CNS- less adverse effects
Oral absorption
Licensed in pigs and dogs

17
Q

What is aspirin used for?

A

Anti-clotting agent- inhibits platelet aggregation
Significant adverse effects- vomiting, GI ulceration, anorexia
Inhibits COX 1

18
Q

What are exogenous glucocorticoids used for?

A

Reversing all types of inflammatory reaction

In high doses as immunosuppressive drugs

19
Q

What are the anti-inflammatory effects of glucocorticoids on cells?

A

Decreases extravasation of neutrophils
Decreased activation of neutrophils, macrophages, mast cells
Decreased fibroblast function
Decreased production of collagen and glycosaminoglycans which can lead to decreased wound healing

20
Q

What are the anti-inflammatory effects of glucocorticoids on chemical mediators?

A

Decreased production of prostanoids (COX2)
Decreased generation of cytokines
Decreased complement components of plasma
Decreased IgG production
Decreased synthesis of nitric oxide
Decreased histamine release from basophils and mast cells
Increased synthesis of anti-inflammatory mediators

21
Q

How are glucocorticoids administered?

A

Orally, systemically, intra-articular, drops in eye, ointment and creams

22
Q

What are the main uses of glucocorticoids?

A

Replacement therapy for dogs with Addisons disease

Anti-inflammatory and immunosuppressive therapy

23
Q

What are the adverse effects of glucocorticoids?

A
Suppression of the response to infection/injury
Wound healing impaired
Cushing's syndrome
Latrogenic hypoadrenocorticism 
Osteoperosis
Hyperglycaemia 
Muscle wasting
Fluids and electrolyte imbalances
Oedema
Reduced milk yield in dairy cows 
GI ulceration 
Abortion in late pregnancy
Laminitis
24
Q

What are the contra-indications of glucocorticoids?

A
Diabetes mellitus
Infections
Corneal ulceration
Cardiac disease
Laminitis
Pregnancy