Diversity in Veterinary Pharmacology

Question 1

Noradrenaline

Answer 1

Adrenergic agonist
a1>a2=b1>b2
No methyl group

Question 2

Adrenaline

Answer 2

Adrenergic agonist

a2>a1>b1=b2

Question 3

Salbutamol

Answer 3

B adrenergic agonist

Question 4

Aspirin

Answer 4

NSAID
COX (cyclo oxygenase) inhibitor
(Dioxygenase and perioxidase)
Decrease prostaglandin synthesis
Aetylsalicylic acid
Inhibit COX 1 = undesired effects
Inhibit COX 2 = desired effects

Question 5

Phenylbutazone

Answer 5

Eliminated principally by drug metabolism
Phase 1 - synthetic enzymes
Phase 2 - conjugating enzymes
Metabolism is species dependent

Question 6

Ivermectin

Answer 6

Anthelmintic –> flaccid paralysis
Opens Glu-gated Cl- channels - only in invertebrates
Breed sensitivities - accumulates in CSF of collies

Question 7

Ibuprofen

Answer 7

Non-selective COX inhibitor
Arylpropionic acid derivative
GI ulceration
Renal failure
Entero-hepatic circulation - high concs excreted in bile and reabsorbed

Question 8

Carprofen

Answer 8

COX 1 inhibitor humans
COX 2 inhibitor cats/dogs
Arylpropionic acid derivative
Photoallergen
UV causes hotodehalogenation to free radical that binds proteins

Question 9

Paracetamol

Answer 9

Highly toxic to cats and dogs
Cats incapable of Phase 2 metabolism - toxic metabolites accumulate
Glucuronyl transferase absent in cats
Haemotoxicity
N-acetylation deficient in cats and dogs
Dogs - no NAT 1 or 2
Cats - no NAT 2

Question 10

Coumarin analogues

Answer 10

Eg warfarin

Dicoumarol - sweet clover disease, spoilt sweet clover silages

Question 11

Warfarin

Answer 11

Synthetic
Can’t smell or taste
Competitive inhibitor for Vit K epoxide reductase
Prevents activation/reduction of Vitamin K
Vit K is cofactor for PTM of glutamate so..
Prevents carboxylation of glutamate residues
Disrupts coagulation cascade (Factors II, VII, IX, X)
Decrease thrombin formation, less fibrin

Question 12

Theobromine

Answer 12

3,7-Dimethylxanthine, closely related to caffeine
Toxic alkaloid in chocolate
Lethal dose = 300-1000mg/kg
Agitation, hyperexcitability, cardiotoxicity
Unusually long half life in dogs (18hrs)

Question 13

Xanthine

Answer 13

Oxidised purine

Question 14

Theophylline

Answer 14

1,3-dimethylxanthine

Question 15

Caffeine

Answer 15

1,3,7-trimethylxanthine
Demethylation to methylxanthines and xanthines
Oxidation to uric acid derivatives

Question 16

Etamiphylline

Answer 16

A methylxanthine

Used as a veterinary cardiac/respiratory stimulant

Question 17

Methylxanthines

Answer 17

Antagonists of adenosine receptors
Inhibitors of phosphodiesterases
-Increase levels of cAMP and cGMP
Positive iono/chronotropic effects
vaso/bronchodilators
Cardiac/CNS stimulant
Activate ryanodine receptors

Question 18

Flunixin

Answer 18

NSAID
Horses cattle and pigs
GI ulceration

Question 19

Loperamide

Answer 19

Opioid drug used against diarrhoea

u-opioid receptor agonist in myenteric plexus of large intestine - not CNS

Question 20

N-acetyl cysteine

Answer 20

Mucolytic agent

Used in paracetamol overdose