NSAID

Question 1

Describe enzymes NSAIDs work on

Answer 1

Membrane lipids are converted to arachadonic acid via phospholipase A. Then AA is converted into prostaglandins via COX (cyclooxygenase)

Question 2

Describe the MOA of NSAIDs

Answer 2

Inhibit PG production by inhibiting COX enzyme

Question 3

COX1 - functions

Answer 3

Constitutive PG - housekeeping, GI protection, platelet function, renal blood flow

Question 4

COX2 functions

Answer 4

Inducible PG - pain, fever, inflammation

Question 5

Describe COX1 effect on platelets

Answer 5

Decreases synthesis of thromboxane which is necessary for platelet aggregation via competitive inhibition. Can last 2-3 days.

Question 6

Type of NSAID- meloxicam

Answer 6

Selective

Question 7

Type of NSAID- ketoprofen

Answer 7

Non

Question 8

Type of NSAID- aspirin

Answer 8

Non

Question 9

Type of NSAID- firocoxib

Answer 9

Selective

Question 10

Type of NSAID- Carprofen

Answer 10

Selective

Question 11

Type of NSAID- Deracoxib

Answer 11

Sel (deramaxx)

Question 12

Type of NSAID- prioxicam

Answer 12

Non

Question 13

Type of NSAID- robenacoxib

Answer 13

Sel (onsior)

Question 14

Aspirin- MOA

Answer 14

Irreversible acetylation of COX1, effect on platelets for 7-10 days (life of platelet)

Question 15

Define IC50

Answer 15

amount of drug needed to inhibit 50% of each enzyme; >1 = selective,

Question 16

Contraindications of NSAIDS

Answer 16

Renal dz, liver dz, GI dz, mast cell tumors, corticosteroids, surgery, cushing’s, cats

Question 17

Describe metabolism of NSAIDs

Answer 17

Liver metabolism via glucuronidation (or oxidative enzyme)

Question 18

NSAID elimination

Answer 18

Urine or bile excretion of metabolites

Question 19

Why are NSAIDs contraindicated in kidney disease

Answer 19

PGs from COX1 maintain blood flow in hypotension

Question 20

Why are NSAIDs contraindicated in GI dz

Answer 20

Inhibit PGE production which protects mucosa

Question 21

What drug can be given with NSAIDs to protect GI

Answer 21

Misoprostol (synthetic PGE)

Question 22

How can NSAIDs cause gastritis

Answer 22

Decreased mucosal blood flow and increased neutrophil adherance to vasculature

Question 23

Why are mast cell tumors contraindication

Answer 23

Histamine is a GI protectant

Question 24

Why are NSAIDs contraindicated in corticosteroid use

Answer 24

Corticosteroids decrease GI health via other mechanism, so additive effect will be worse

Question 25

Type of NSAID- tepoxalin

Answer 25

Non selective- Dual COX/LOX inhibitor- inhibition of LOX decreases GI effects bc leukotrienes are gastrotoxic

Question 26

Why are NSAIDs contraindicated in cats

Answer 26

Less glucuronidation leading to elongated half life of elimination

Question 27

NSAID side effects- cats vs dogs

Answer 27

Cats- renal Dogs- GI

Question 28

Which NSAID is cleared by oxidative enzymes

Answer 28

Meloxicam in cats

Question 29

What drug can lead to methemoglobinemia in cats

Answer 29

Acetaminophen - toxicmetabolite NaPb

Question 30

What is the antidote to acetaminophen in cats

Answer 30

acetylcysteine - a glutathione precursor which detoxifies

Question 31

Which NSAIDs are best for perioperative use, why?

Answer 31

Inj rimadyl and meloxicam, no effect on platelets

Question 32

When should NSAIDs be given around sx and why

Answer 32

30-60 min prior to recovery to give time to eliminate existing prostaglandins