Pharmacology

Question 1

What is the cascade of events when using GA ?

Answer 1

Question 2

Describe the major organ responses of β1 and β2 agonists

Answer 2

Question 3

1. What Class of Drug induces Vomiting?
2. Give an example of these
3. What Class of drug would stop vomiting? What must you do before administration?
4. Give an example of these

Answer 3

1. Emetics
2. Apomorphine (dopamine agonist) tablet mixed with water and then give IV or SC. or tab in the conjunctival sac. NOT FOR USE IN CATS
   
   • Xylazine (Alpha-2 agonist at the CTZ) For CATS
3. Anti-Emetics - Rule out GIT obstruction
4. Metoclopramide (Maxolon) 1. anti-emetic effect (central action) 2. weak upper GI prokinetic effect (peripheral action) IV, IM, PO. Short DOA >6hrs
   
   • Prochlorperazine (Stemetil) Blocks the CTZ via antidopaminergic and antihistaminergic effects
   • Ondansetron (Zofran) Blocks Serotonin (5-HT₃)
   • Maropitant (Cerenia) Highly efficacious neurokinin-1 blocker. Stings! Use cold!

Question 4

Define and explain the process of protein binding ?

Answer 4

V_d is affected by protein binding.

Drug molecules can bind to plasma proteins (albumin) = bound drugs.

Only free drugs can leave the blood

Protein binding is ; reversible & dynamic

with bound and unbound drugs is equilibrium.

Question 5

Whatdo we need to check before using Prednislone eyedrops?

Answer 5

Must check for the presence of a corneal ulcer. DO NOT USE, can cause ulcer to get worse and eye rupture.

Question 6

Provide examples of drugs which may inhibit or induce HME’s ? Hepatic metabolising enzymes

Answer 6

• Induced by anti-convulsants
• Inhibited by ketoconazole (anti-fungal) , can inhibit an expensive drug (cyclosporin) that is used in itchy skin - reducing the cost by using less of the more expensive drug.

Question 7

• NSAID’s MOA will reduce inflammation by inhibiting cyclo-oxygenase (COX). Which COX would we prefer to select for?
• Name some NSAID’s that Select (Inhibit) for this COX.
• What is a NSAID with no selectivity

Answer 7

1. COX-2
2. Cox 2 Selective
   
   • Firocoxib - Horses, Dogs, Cats
   • Carprofen - Not as Selective for Horses
   • Meloxicam
3. Ketoprofen

Question 8

What is the clinical uses of Tropicamide

Answer 8

Question 9

1. What is a MIC?
2. What is MBC
3. What if MBC>>>MIC?
4. What if MBC ~ MIC?

Answer 9

Minimun inhibitory concentration

= the lowest concentration that prevents visible growth after 24hours incubation

Calculated quantitatively by serial dilution techniques

A MIC is a unique number that refers to a specific concentration of an antibiotic that will inhibit the growth of a particular bacterium. This means that there is a MIC for every combination of antibiotic-bacterium

1. Minimum Bactericidal concentration = The lowest concentration where 99.9% of a culture is killed after 24hrs incubation.
2. If MBC >>> MIC = Bacteristatic (microorganism arrestor)
3. If MBC ~ mic = Bactericidal (microorganism killer)

Question 10

Corticosteroids

What is a :-

• Glucocorticoids
• Mineralocorticoids

Answer 10

• Glucocorticoid - specifically relating to the corticosteroids predominatly produced by the Zona fasciculata “zone” of the adrenal cortex eg cortisol
• Mineralocorticoid - specifically relating to the corticosteroids predominantly produced by the Zona glomerulosa “zone” of the adrenal cortex eg. aldosterone

Question 11

How does the vaopur concentration affect anaesthesia ?

Why does this occur ?

Answer 11

The more lipid soluble the vaopur the slower the

* anaesthetic induction

* rate of change of depth

* rate of recovery

Why - because the more molecules need to solubilise in the blood for equilibrium to establish or re-establish itself.

Question 12

Explain the difference between the pattern of drug distrubution and the volume of distribution?

Answer 12

The propensity that a drug has for leaving the blood and entering thte tissues is calculated by the pharmacokinetic term volume of distribution (V_d).

V_d does not inform on the pattern of distrubtion ( lots of drugs in the brain) just the propensity of the drug to leave the blood.

Question 13

List the sympathetic adrenoceptor agonist drugs and their uses.

Answer 13

• Adrenaline - Anaphylaxis, added to improve other drugs efficacy, cardiac arrest
• Noradrenaline - Similar to Adr but less Beta2 effects
• Salbutamol, Salmeteral - Beta2 agonists for rapid relief of bronchiolar constriction
• Clenbuterol - Beta2 Agonist primary affect the respiratory system but can cause uterine relaxation. This is used to facilitate calvings.
• Phenylpropanolamine - Alpha1 - Constriction of urethral smooth muscle retaining urine therefore used for urinary incontinence
• Xylazine - ALpha2 agonist - sedative
• Yohimbine - Alpha2 antagonist - Reverse sedative effects of Xylazine
• Phenoxybenzamine - Aplha1 antagonist - Relaxing the smooth muscle of the uretheral sphincter - helps clear urinary blockages
• Propranolol, Atenolol - Beta antagonist - Beta Blockers

Question 14

Describe the factors and identify the rate limiting factors that affect drug absorption?

Answer 14

Disintegration

Dissolution

Absorption

Drug solubility

Surface area

First past metabolism ; exception of oral mucosa & rectum, all absorption from the ailmentary canal , goes directly into the portal vein an so drugs will be exposed to the metabolising enzymes in the liver prior to reaching the systemic circulation.

Vascularity / disease process; decreased blood supply to the site of admin will decrease absorption, decreased GIT motility , delayed gastric emptying leading to reduced exposure time to the small intestine.

Question 15

Bupviacaine (LA) is beneficial for what applications ?

Why is this the case ? & when is it no appropriate to use ?

Answer 15

• Good for epidurals
• Long acting due to strong affinity with the sodium channels ,slow associatation and disassociation means its long lasting, but also slow to be effective
• when rapid desensitisation is required, due to the slow onset of action it takes a long time to become effective

Question 16

Explain what ADT or EOD is?

What must you do when a patient is longer term steroids? and why?

Answer 16

Alternate Day Therapy

A method for achieving the lowest possible dose that is still therapeutic, eg Treating a patient with prenisolone for its atopy.

Question 17

Cephalexin

Answer 17

Beta Lactam

1st Generation Cephalosporin

• Predominantly Gram +ve
• Well suited for Staph pyoderm

Question 18

Define loading dose and maintenance dose rate ?

Answer 18

Loading dose - amount of drug given intially to obtain the desired plasma concentration asap, expressed in mg / kg.

Maintenance dose rate; rate at which drug needs to be administered to maintain a desireg plasma concentration , expressed in mg/kg/min.

Question 19

Define the pharmacokinetic parameter of elimination half life T 1/2 .

Answer 19

Is defined as the time taken for the blood/plasma drug concentration to fall by 1/2 (50%).

The pharmacokinetic parameters that determine half - life , are V_d and clearance.

Question 20

Tetracyclines

1. What is the Spectrum of Activity for tetracyclines?
2. List the specific diseases where these antibiotics are indicated.
3. List the limitations, side-effects
4. List teh Tetracyclines

Answer 20

Tetracyclines

1. Broad Spectrum bacteriostatic - Gram +ves, Gram -ves (not Pseudomonas), Anaerobes (variable)
2. Gold Standard against Chlamydia and good agains Mycoplasma and Rickettsia
3. Common side effect is GIT upset with given orally. Some nephrotoxicity,
4. Oxytetracycline, Doxycycline (upper respiratory tract small animals)

Question 21

Name a phosphodiesterase inhibitor

Mode of Action

Contraindications

Answer 21

Pimobendan

Generalised vasodilation including pulmonary, artery less afterload.

Weak Vasodilator

Question 22

Can I use Corticosteroids as an antimicriobial?

Answer 22

NO

Question 23

Why are Second generation H₁ antagonists (eg Cetirizine) often advitised as “non drowsy?

Answer 23

Histamine contributes to arousal (wakefulness) in the brain and therefore the antagonism of histamine can cause drowsiness. Because the 2nd generation H₁ antihistamines do not cross the blood brain barrier significantly (unlike 1st Generation) this side effect reduced and these drugs can therefore be sold as being non drowsy

Question 24

• What do Macrocylic Lactones kill
• What is their MOA
• Toxicity?
• Name some?

Answer 24

• Broad spectrum - nematondes and arthropods (not trematodes or cestodes).
  
  • Equine -endo and ecto-parasites as oral
  • Cattle endo amd ecto-parasites as topical pour-ons
  • Sheep endoparasites as oral drenches
  • Small animal Heartworm prevention and mite management
• MOA - agonist at glutamate R & GABA-Gated chloride ion channels
• Toxicity, Safe except in Collie breeds who MDR1 gene
• Ivermectin (heartguard plus), Moxidectin (Proheart), Selamectin, Milbemycin

Question 25

What is the equipment needed for an IV or inhalant GA ? What control and speed do you have for IV and inhalants for induction and maintenance ?

Answer 25

IV- minimal equip ; suitable for fieldwork, IM for wild animals. Inhalant - substantial & costly, 02 supply, vaporiser, anaesthetic circuit. Induction IV - easy, quick & smooth, Bolus doses can be dangerous. Maint -difficult to make even if using additional boluses doses. finer control if using IV CRI. Induction Inhalant - difficult, slow , usually struggle but maintenance has fine control.

Question 26

1. What is the main side effect of NSAID use? 2. What can we try and do to alleviate these side effects? 3. What are the other NSAID Side Effects? 4. What over the counter NSAID may kill a cat?

Answer 26

1. Mostly related to inadvertent inhibition of Cox1 NSAIDS potentially cause Erosion, ulceration and haemorrhage of the GI tract. 2. Use of anti-ulcer mediations * Histamine type-2 blockers * Proton-Pump inhibitors * PGE₁ analogues * Barrier medications 3. Effects - Related to the inadvertant inhibition of COX-1 1. Altered Platelet Function * irreversibly reduces platelet thromboxane (TXA₂) and temporarily decrease endothelial PGI₂ --\> a net decrease in platelet aggregation used therapeutically as an antithrombic 2. Kidney * Potential for * Water retention --\> Hypertension * Decreased renal blood flow leading to interstital papillary necrosis and nephritis * Patients with heart disease are at greater risk of kidney related NSAID complications 4. 1/2 a 500mg paracetamol

Question 27

Explain the difference between Efficacy and Potency

Answer 27

Efficacy - maximum effect that a drug can produce regardless of dose. Potency - amount of a drug that is needed to produce a given effect

Question 28

Cefovecin (Convenia)

Answer 28

Beta Lactam Very high protein binding (\>99%) and decreases clearance rates in dogs and cats prolongs DOA to 2 weeks (will be more efficacious if given q7d) Skin, Urinary and dental conditions Difficult to pill animals and where compliance will be an issue, costs about the same as the equivalent oral course. But Beware of the colour change.

Question 29

Drugs are scheduled depending on what 2 factors?

Answer 29

* The risk of harm to people when used appropriately and inappropriately * The risk of addiction to people eg Heroin

Question 30

What does a Insect Growth Regulator (IGR) do * What is the downside? * Name some

Answer 30

* IGR * Insect Growth Hormone antagonists (they dont grow up, - eg Methoprene (the Plus in frontline) * Inhibit the chitin synthesis pathways --\> cannot develop, needed for exoskeleton and eggs * Not an adulticidal, so must give one if adults are present * Fipronnil, Imidacloprid, Spinosad, Indoxacarb (Activyl)

Question 31

Beta-Lactams 1. What is the MOA for Beta Lactams 2. Define the Sub-Groups

Answer 31

Beta Lactams 1. Penicillin tranverses Gram +ve cell wall and reaches cell membrane, Binds to Penicillin Binding Protien (PBP), Disrupts Cell wall synthesis, Bacteria lyse due ot impaired osmotic regulation. BetaLactams can only kill bacteria during thei replication phase. It is a Time Dependent Bactercidal 2. SubGroups * Penicillins, * Cephalosporins, * Carbapenems

Question 32

Beta Lactams ## Footnote Of the Carbapenem Sub Group what is the Spectrum of Action

Answer 32

1. One of our Reserve Drug Classes * extreamly efficacious * Gram +ve and -ve aerobes and anaerobes * highly resistant to beta-lactamases * not effective agains vancomycin-resistant Enterococci (VRE) or Methicillin-Resistant Staphylococcus aureus (MSRA) * Often used for severly ill immunocompromised people * Imipenem, Meropenem

Question 33

1. What is a Prokinetics? And when are they used? 2. What do you need to beware of when using? 3. Name some

Answer 33

1. Stimulating GIT motility, GIT motility often decreased after surgery 2. Can make GIT obstructions worse 3. Metoclopramine * Cisapride Dose-Dependent increase in motility from Stomach --\> LI

Question 34

What Gram +ve Obligate Anaerobe is found in ruminants

Answer 34

Clostridum

Question 35

Understand when a loading dose should be administered.

Answer 35

To quickly enter the therapuetic window of desired drug plasma concentration. to "fill up " the V_d. when it is necessary to achieve a high plasma concentration quickly

Question 36

What are the central CNS effects of histamine?

Answer 36

* Maintains wakefulness * emesis * Pharmacokinetic variation * within the H₁ antagonists, lipophilicity can effect the ability to cross the BBB and cause drowsiness

Question 38

Name an α2 antagonist and its Clinical Uses

Answer 38

Yohimbine Used to reverse the sedative effects of xylazine

Question 40

What is the purpose of an excipient?

Answer 40

Excipient is an inactive substance used to carry an active substance. It may make the drug work better or make the drug easier to work with.

Question 41

Understand the factors of how loading doses are administered?

Answer 41

* Bolus * Route Without a LD, 3-5 half lives are required to reach a steady blood concentration. With a LD , steady blood concentration is achieved straight away.

Question 42

Name some of the local anaesthetic ? What is the mode of action for LA?

Answer 42

1. Lignocaine, Mepivacaine, Bupivacaine, Proxymetacine. 2. Blocking conduction of nerve action potentials & binds to receptor site on neurons NA channel -sodium channel closes - no nerve conductions

Question 43

What is a corticosteroid?

Answer 43

* Physiology - The steroids that are produced by the adrenal cortex eg cortisol, aldersterone * Pharmacology - Symthetic steroids with corticosteroid like effect eg prednisolone, dexamethasone, methylprednisolone

Question 44

What are Schedule 5 drugs? Give some examples

Answer 44

Must have the word CAUTION on the lable, very low risk unlikely to cause harm. * Glyphosate (roundup) * Methiocarb (Baysol Snail Pellets) * Petrol * Ethylene glyco (Radiator Coolant) * Warfarin (RatSack)

Question 45

Name the Various Drug Administration Routes and list the advantages and disadvantages to each

Answer 45

There are 2 main routes of administration, Oral (PO = per oral or Per OS) and Parenteral (given by injection). Oral ;drug absorption unreliable and slow through gi tract. safest, economical & convenient route. Parenteral abreviations -; Most rapid route , high concentrations quickly in systemic circulation. injection injuries, celluitis, pain. IV - Intravenous; immediate pharmalogical response direct into bloodstream IM - Intramuscular; greater response than SC due to greater tissue blood flow SC, SQ - Subcutaneous ; slow rate of absorption , sustained effect. Intrathercal ; injected directed into the spinal subarachnoid space, bypasses blood brain barrier. Epidural; injected into spinal canal on or outside the dura mater Intraosseous; delivered into bone marrow Intra- articular ; delivered into synovial cavity of a joint Intraperitoneal; admin into peritoneal cavity Intrapleural; admin into the pleura

Question 46

What are the legal authorities who regulate drugs

Answer 46

WA Health Dept Dept of Agriculture Veterinary Surgeons Board

Question 47

Of teh 3 Main Antibacterial targes which are Time depenent, Dose Dependent bactercidals or Bacteristatic?

Answer 47

Question 48

Explain Placebo Controlled - (negative controlled)

Answer 48

A term used to describe a method of research in which an inactive substance (a placebo) is given to one group of participants, while the treatment (usually a drug or vaccine) being tested is given to another group

Question 49

Which GA are considered barbituates ? What is the mode of action for barbituates ? What other applications suit this GA ?

Answer 49

1. Thiopentone & pentobarbitone 2. Barbituates decrease the CNS excitability via GABA agonism. 3. injectable GA, anticonvulsant, humane euthanasia.

Question 50

List the uses of Adrenaline and what adrenergic receptors it increases or decreases activity of.

Answer 50

Question 51

What is the sequence of events that translate an idea into a registered and scheduled drug?

Answer 51

* Drug Development - Very expensive, long winded process undertaken by the drug company * Drug Testing - Huge financial investment to get the drug to the market, testing is done under the supervision of the body who will register the drug. * Registration - Australian Pesticides and Veterinary Medicines Authority (APVMA) registration legalises supply, sale and use of veterinary chemical. Therapeutic Goods Administration (TGA) registers the drugs for people often utilising independent scientific advice. * Scheduling - TGA schedule all "poisons" via Standard for the Uniform Scheduling of Medicines and Poisons.

Question 52

Of the following Drugs which will agonise which adrenergic receptors? * Adrenaline (Adr) * Noradrenaline (NAdr) * Salbutamol (=Albuterol), Salmeterol, Clenbuterol * Phenylpropanolamine * Xylazine

Answer 52

Question 53

In terms of Inhalant GA , what does MAC stand for? What is MAC ? and how does this affect the vaopur setting.

Answer 53

Minimum Alveolar Concentration ## Footnote Which is the partial pressure (concentration) if anaesthetic vapour required to anaesthetise EG an anaesthetic vapour with a high MAC requires a lot of the vapour to be inhaled to achieve anaesthesia and so the vapour setting will be higher.

Question 54

Procaine Penicillin

Answer 54

Beta Lactam ## Footnote Large Animal Practices use this alot Excellent anaerobic coverage (G+ and G-) DOES NOT work against Beta lactamase producing bacteria IM, SC NEVER IV

Question 55

GA barbitaute Thiopentone is an ultra short acting anaesthetic and has a ___________ anaesthetic effect ? How does this affect its useage ? Other considerations ?

Answer 55

Thiopentone is a cumulative anaesthetic. the culmative effect is most pronounced in lean dogs because there is less fat for the drug to redistribute to , leads to very long recoveries from post op sedation Avoid thiopentone use in sighthounds, and it needs to be in a highly alkaline (ph11) solution to maintain solubility , dont use in liver failure or for caesareans.

Question 56

List the things that the Sympathetic chain of the Autonomic Nervous System controls

Answer 56

Fight or Flight

Question 57

What are Corticosteriod side effects?

Answer 57

1. All the NSAID side effect (COX inhibition) * GIT Ulceration * Degrease PGE and Decrease PGI₂ * additional action here is that is unclear decrease mucosal blood flow * Kidney failure, hypertension 2. Metabolic * iatrogenic hyperadrenocorticism during therapy * Suppression of the hypothalmic-Pituitary-Adrenal axis (HPA axis) * Sudden cessation of corticosteroids leads to hypoadrenocortical crisis 3. Immune System * Immunosuppression * more prone to infections and those infections will be more severe.

Question 58

List the uses of Noradrenaline and what adrenergic receptors it increases or decreases activity of.

Answer 58

Similar to Adr but has considerably less β2 effects

Question 59

What are the Parasympatholitic drugs and thir clinical uses

Answer 59

Question 60

Fluroquinolones 1. What is the Mode of Action. 2. Is there resistance and where should we not use them?

Answer 60

Flouroquinolones * MOA = Inhibits DNA gyrase action --\> Cell Death as cannot cut, untangle and rejoin DNA * Big probelms once widespread resistance emerges, DO NOT use in Australia for food producing animals. * REnal degeneration in Cats if label dose exceeded (5mg/kg), Cartlage Deformities (Chelates magnesium) avoid in growing animals

Question 61

What are Schedule 10 drugs? Give some examples

Answer 61

Substance of such danger to health as to warrant prohibition of sale, supply and use Illegal importation Substances that are prohibited for the purpose listed in each poison. * Very strong alkali for domestic uses eg pH\>11.5 (food additives) or Ph\>12.5 (dishwashing additives) * Ethylene glycol at \> 0.25% in toothpaste or mouthwash * formaldehyde at \>0.1% in oral hygine products * Paints with \>0.1% lead

Question 62

Briefly crtitique the manufactruere claim that their insect growth regulator registered for use against sheep lice is a "rapig knockdown lousicide" ?

Answer 62

Insect grwoth regulators by inhibitinh insect growth hormone and chitin synthesis they are not adulticides. Because they do not directly kill the lice, it is misleading to refer to them as lousicides.

Question 63

Another LA topical use lignocaine with phenylephrine is more commonly used for ? Mode of action ? Other uses ?

Answer 63

topical LA to spray onto larynx of a cat prior to intubation, Desensitises (not paralysis) & prevents potentially fatal laryngospasm in the cat Can also be used for removing nasal foreign bodies & nose bleeds.

Question 64

After Staining Bacteria what colour do Gram Positive bacteria stain? What colour do Gram negative bacteria stain?

Answer 64

Purple = Gram Positive Red = Gram Negative

Question 65

In inhalant GA high lipid solubility gives you ?

Answer 65

A slow and low repsonse.

Question 66

List the Neurotransmitters and receptors for the sympathetic, parasympathetic, somatic and neuroendocrine systems

Answer 66

Question 67

Discuss with specific examples, the range of sequale for drug metabolism ?

Answer 67

* Excretion of water soluble metabolite * Conversion of pro-drugs, through the formation of active metabolites (ie tramadol & prednisone)

Question 68

H₁ antihistamine toxicity?

Answer 68

* CNS * sedation (drowsiness) * But at high doses of after rapid IV administration, seizures or CNS excitement * DO NOT GIVE H₁ antihistamines intravenously * Some antimuscarinic effects (dry as a bone, mad as ahatter, red as a beet) * dry mouth, mydriasis, tachycardia

Question 69

Define the term pharmacokinetic parameter clearance (CL).

Answer 69

Clearance describes the ability of an individual organ or the body to eliminate a drug.

Question 70

List 3 major types of Diuretics Relate site of action

Answer 70

Loop - Frusemide - Ascending Loop of Henley Potassium Sparing (Spironolactone) - Collecting ducts Osmotic (mannitol) -Moves fluid from tissues into plasma

Question 71

What two controls should a drug study consist of? Describe why these are important.

Answer 71

1) Positive Control, Negative/Placebo Control. 2) In a drug study, a positive control is a compound that is widely accepted to have efficacy for a desired effect. A negative control should not have any effect, so any effect seen should be a representation of the error inherent to the study. By testing a drug against both of these controls, its efficacy AND proven inefficacy. These same controls can be used to measure a compound's safety

Question 72

Name some injectable GA ?

Answer 72

Thiopentone , pentobarbitone, propofol, alfaxalone, ketamine, teletamine-zolazepam.

Question 73

List the effects of Sympathetic discharge (aganosim)

Answer 73

Question 74

What is a Placebo?

Answer 74

A Placebo is a tablet, injection etc that does not contain the active ingredient. It should be identical in its taste, appearance etc except that it has no effect (therapeutic or adverse.

Question 75

What is the mode of action of a Glucocorticoid?

Answer 75

It inhibits Phospholipase A₂ therefor decreasing Arachidonic Acid which suppresses COX (1 & 2) and LOX synthesis. Therefore decreasing prostaglandins and leukotrienes

Question 76

Describe what is meant by Drug Absorption?

Answer 76

Getting the drug from site of administration into the blood (systemic circulation). No absorption phase for IV injections. Rate and extent the drug gets into the blood is calcuated by the pharmacokinetic term - *bioavailability*

Question 77

What are Schedule 6 drugs? Give some examples

Answer 77

Poison - Moderate potential for harm. Distinctive packaging with strong warnings and safety instructions * Arsenic (Ant Bait) * Formaldehyde * Selenium * Brodifacoum

Question 78

Phenylpropanolamine can be used for urinary incontinence. Why must we be careful of its use in hypertensive patients? (1 mark)

Answer 78

This drug is an alpha-1 agonist and will therefore have a vasoconstrictive effect on the systemic blood supply (except muscles). The use of this drug would therefore be expected to exacerbate the hypertension in the hypertensive patient.

Question 79

Name some Fluoroquinolones

Answer 79

* Enrofloxacin * Ciprofloxacin * MarboFloxacin

Question 80

What is Drug Compounding

Answer 80

It is the manipulation of a drug to form a medication that is prepared by a veterinarian or pharmacist on instruction (prescription) from an authorised person e.g. doctor, dentist or veterinary surgeon, to meet the specific medical needs of an individual patient

Question 81

Metronidazole 1. MOA? 2. Bactercidal or Bacterstatic? 3. Spectrum of Action

Answer 81

Metronidozole * Unknown MOA * Bactercidal * Excellent Anaerobic and anti-protozoal efficacy * Kills Clostridium difficile (The bad gut anaerobe that prolifereates after you accidently wipe out the normal gut flora.

Question 82

1. What happens in anaphylaxis. 2. What is used in the treatment of anaphylaxis and why? 3. Why would we not use H₁ antihistamine for anaphylaxis 4. Can you use a H₁ antihistamine on a puppy with a puffy face?

Answer 82

IgE binds to mast cells and cause (1) massive degranulation to release large quantities of histamine and (2) the release of other mediators * respiratory smooth muscle contration --\> bronchiolar constriction * Arteriolar vasodilation --\> Hypotension (species dependent) 1. Adrenaline is used in the treatment of anaphylaxis because its ability to rapidly reverse hypotension and bronchiolar constriction is unmatched 2. May work but you may be dead before the drug kicks in. May not work as other mediators are involved in anaphylaxis (cytokines, eicosanoids) 3. Yes a hypersensitivity reaction to a vaccine, bee sting etc can be symptomatically treated with a H₁ antihistamine, usually given with a glucocorticoid

Question 83

Staphylococcus, Streptococcus and Enteroccus are all what kind of bacteria?

Answer 83

Gram +ve Facultative Anaerobe (Uses ATP when in presence of Oxygen and Fermation when not)

Question 84

Propofol is a GA agent, what is the mode of action ? Why are the benefits of using it for a GA? Given as an IV or other ? What is the general colour ? Other uses ?

Answer 84

GABA Agonist with CVS depression, non cumulative drug. rapidly taken up by the brain then rapidly redistributed and extensively metabolised which accounts for a rapid & smooth induction anaesthetic along with a smooth recovery for anaesthesia. IV -extravascular absorption is poor White goood use in caesareans as its rapidly eliminated by newborns & anticonvulsant ; MPEC will condiser CRI propofol if diazepam( +/- phenobarbiatone) is unable to control seizures.

Question 85

Explain Randomisation

Answer 85

A study in which people are allocated at random (by chance alone) to receive one of several clinical interventions

Question 86

Beta Lactams 1. In the Subgroup Penicillins give us the Spectrum of activity

Answer 86

1. Natural Penicillins * Narrow Spectrum * Predominatly Gram +ves and Anaerobes * Staphylococcus (only non penicillinase producing) Streptococcus, Obligate anaerobes (eg Fusobacterium) * Penicillin G (Procaine and benzathine salts), Benzylpenicillin 2. Aminopenicillins * Broader Spectrum * Same as Natural Penicillins plus some Gram -ves eg. E.Coli and Proteus * Amoxycillin, Ampicillin 3. Others * Beta-Lactamase stable penicillins eg methicillin (MRSA), cloxacillin * Extended spectrum eg. ticarcillin, piperacillin

Question 87

* What is the MOA for Pyrethrins & Pyrethroids * Give some examples

Answer 87

Affects the sodium channels capacity to depolarise --\> death of parasite * Anything endint with **thrin** allethrin, permethrin

Question 88

What are our front line corticosteroids that we use in Veterinary practice, What are their Duration of Action

Answer 88

* Prednisolone, 24-36hrs (IV, Tablet, Oral Liquid, Granules [For horses/Chronic Skin conditions]) * Dexamethasone *Overused and Misused* DOA 72hrs, Onlable Pigs, Cattle, Sheep, Horses, Cats and Dogs * Hydrocortisone acetate - Old topical cream that gets licked off * Hydrocortisone aceponate "Cortavance" (Brilliant idea absorbed through skin)

Question 89

**HISTAMINE** What does a H₁ receptor do What does a H₂ receptor do

Answer 89

1. H₁ receptor * Veno- and arterio dilation, increased vascular permeability --\> *erythema & oedema* during inflammation * Contraction of GIT and respiratory smooth muscle --\> *anaphylaxis* * Therefoe, the H₁ -antagonists are used for histamine-mediated inflammatory processes e.g pollen allergies 2. H₂ receptor * Mediates gastric acid secretion using non-mast cell poool * therefore, the H₂-antagonists are used for histamine-mediated gastric ulceration

Question 90

Why is the idea of a single dose of each antibiotic (eg what the dose rate of clav?) an overly simplistic one?

Answer 90

Different species (and even different strains and different isolates of the same species) of bacteria will have different susceptibilities to the same antibiotic. so choosing one dose for each antibiotic, and expecting it to applyy to all bacteria is naive, ignorant, cretenous and moronic

Question 91

What are the legal authorities that oversea the testing, registration, scheduling and regulation of various poisons

Answer 91

APVMA for Veterinary Chemicals TGA for Drugs for people

Question 92

Name a topical antifungal sutible for dermatophytosis in a dog

Answer 92

Miconazole, clotrimazole

Question 93

Decribe the fate of the drug

Answer 93

Question 94

Define and explain the concept of apparent volume of distribution ?

Answer 94

V is therefore an *apparent* volume of distribution , it is mathematically determined and so is not bound by rules of physiology.

Question 95

How do we find out is a pathogen is sensitive or resistant to the antibiotics we have available?

Answer 95

1. Grow the Bacteria 2. Add a disc of antibiotic and observe that happens

Question 96

Amoxycillin - Clavulanic Acid HotSpots - Staphylococcus pseudintermedius

Answer 96

Beta Lactam Most common antibiotic in small animal practice * Predominantly Gram +ve * Excelent Anaerobic (G+ & G-) coverage * Works against many Beta-lactamase producing bacteria * IM, SC NEVER IV * SID

Question 97

What NSAIDs do we use for Equine patients

Answer 97

* Phenylbutazone "Bute" * No Cox1/COX2 selectivity * Excellent analgesic for lame horses * Meloxicam * Large Animal increased concentration * uncommonly used * fewer side effects than Bute * Flunixin * Very Common * Excellent analgesic for colic horses

Question 98

What are Schedule 1 drugs? Give some examples

Answer 98

This is not currently in use. No examples

Question 99

1. When using a Laxative what do you need to be careful of 2. When are laxitives used in clinics 3. Name a Emollient Laxative 4. What is a Cathartic 5. Name some Osmotic cathartics

Answer 99

1. Beware of dehydration 2. Horse sand colic, Old dehydrated cat. 3. Paraffin Oil, Docusate Sodium (Coloxyl) 4. (purgatives = more fluidy evacuation 5. Magnesium Sulphate (Epsom Salts)

Question 100

1. When using ketamine , what cannot be used as an indication of effectiveness ? 2. What ketamine variations are good for sheep and horses ? 3. Other effects of ketamine ? 4. Human use has it scheduled as an S?

Answer 100

1. Many reflexes are still present (other GA dull the reflexes and can then be used to guide the depth of anaesthesia) 2. Sheep ( xylazine-ketamine) & Horses (xylazine-diazepam-ketamine) 3. No CVS depression, increase in sympathetic drive.Dont use on own-stormy recovery 4. S8 due to human abuse, must be locked away and recorded.

Question 101

What could administration of corticosteroids cause in a horse? Can I give corticosteroids with NSAIDS to Horse? eg Lame horse with an allergy To all other Species of Animal?

Answer 101

Laminitis Yes - Horses seem to be highly resilient to the adverse effects of concurrent use of CSts and NSAIDs No - Synergistic side effects (1+1=3)

Question 102

List the effects of excessive ACh discharge

Answer 102

Question 103

What is the difference between local anaesthetics ? General mode of action ?

Answer 103

* no qualitative differences so all will numb an area equally. variations in speed of onset of action and duration of action are related to the affinity for the receptor. * the nociceptive fibres have less myelin and are closer to the surface of nerve bundles allowing a better chance a LA will work on them

Question 104

Using the graph, classify a drug as being agonist antagonist partial agonist

Answer 104

Question 105

What questions would you ask a prospective compounding pharmacy you are intending to use the services of?

Answer 105

• Does the pharmacist have experience and training in complex compounding of veterinary products and comply with the Pharmacy Board of Australia Compounding Guidelines and published pharmacy practice standards in compounding? • Are (and what) quality assurance programs are in place? • Do sterile compounding facilities comply with the Australian Standards for clean rooms and are there sterility testing programs in place? • What are the Standard Operating Procedures (SOPs) in case of a recall, compliant or adverse reaction? • Does the pharmacist have or have access to the appropriate texts and reference books for animal dosages and side effects?

Question 106

How is Food Withholding Periods determined?

Answer 106

How long till the drug residue drops below the Maximum residue limit (MRL)

Question 107

List the effects of parasympathetic discharge

Answer 107

REST • CVS – decreased heart rate – mild decrease in atrial myocardial contractile strength (weaker effect on ventricles) • Respiratory system – bronchiolar constriction ANd Digest • GIT – profuse watery salivation – increased GIT motility – increased gastric acid secretions – sphincters open – not anal – defaecation • Miscellaneous – micturition via fundic contraction and trigone/sphincter relaxation – pupils contract (miosis) – lacrimation

Question 108

What are the isoxazolines? MOA Name some

Answer 108

Chewable dog tablets for ticks and fleas ## Footnote End with Laner Fluralaner (Bravecto) Afoxolaner (NexGard) Suralaner (Simparica) MOA = Neural Toxicity

Question 109

Understand the advantages and disadvantages of compounded drugs.

Answer 109

1. Advantages 1. Can get what you want • compounds that are no longer commercially viable can be made available to the veterinary market like cisapride (heart attacks in small % of people) • assuming not under patent • assuming raw drug is available 2. Can get it how you want it • exact amounts of drug (e.g. 12.5mg instead of 250mg) in capsules, tablets and injections – e.g. amlodipine – 1/8th of a small tablet • Transdermals – be VERY cautious – can you measure the drug concentration or the effect of the drug (e.g. feline hyperthryoidism)? • flavoured with a wide range of palatants • “polypills” e.g. 3 drugs in 1 pill 3. When you want it • the efficacy and the safety of the products does not need to be proved so things get done quickly 4. Sometimes cheaper • registered products exist but you can use a cheaper compounded version (a “mimic” drug) – compounding pharmacist has access to wholesale prices of drug from chemical supplier – e.g. pimobendan, fluconazole – makes the drug companies VERY upset – illegal in US, not Australia • OWNER CONSENT! 2. Disadvantages 1. Efficacy is unproven – 80% of patients will get better despite what you do – can you OBJECTIVELY measure the plasma concentration or an effect of the drug? • plasma concentrations following the administration of cyclosporine • very difficult to assess the efficacy of analgesics (pain killers), antibiotics and many other drug types 2. Safety is unproven 3. quality control?? • drug company = good manufacturing practice (GMP) = VERY high standard • compounding pharmacist = the professional standards of the PSA 4. how long is the preparation stable for (e.g. what is the expiry date)?? • “intended for immediate usage”, Pharmaceutical Society of Australia (PSA) • for the expiry date, often an arbitrary date of 28 days is applied • an American compounded preparation of doxycycline was found only to be stable for 7 days, despite the unsubstantiated claim of 28 days

Question 110

What are the H₁ Antihistamine drugs * 1st Generation * 2nd Generation What do Immunomodulators do? What are the 2 that we use?

Answer 110

* Chlorpherniramine (for allergies, to lower Corticsteroid doses used in atopy DO NOT GIVE IV) * Cetirizine (Zyrtec) - Less lipophilic so cross the BBB less, so result in less drowsiness, primary used for allergies **Immunomodulators** - Block Interleukin-31 which is involved in sending messages from the periphery to brain that is interpreted as itchiness. (injection of IL-31 elicts a pruritic response, dogs with atopy have higher blood concentrations of IL-31 than those that dont. * Oclacitinib (Apoquel) * Alternative to Glucocorticoid for atopic and allergic dog. * tyrosine kinase inhibitor (Blocks interactions between IL-31 and the nervous system * Lokivetmab (Cytopoint) * Not yet approved by APVMA * OOA = 8hours, DOA = 1 month

Question 111

Beta Lactams ## Footnote Of the Cephalosporin SubGroup What is thier spectrum of activity

Answer 111

1. First Generation * Spectrum similar to aminopenicillins but: * Less anaerobic activity but better activity against Staphylococcus * Cephalexin, Cefazolin 2. Second Generation * Expanded Gram -ve activity * Decreased Gram +ve activity * Not commonly used in some intrammaries for bovine mastitis 3. Third Generaion * Further improved gram -ve activity but reduced gram +ve activity * Ceftiofur, Cefyazidime, Cefovecin

Question 112

What spectrum of activity would you exspect from a topical preparation of imidacloprif and moxidectin in a dog ?

Answer 112

Treatment of fleas, mites (including demodex) and intestingal nematodes. Also prevention of heartworm.

Question 113

Name an α₂ agonist and its Clinical Uses

Answer 113

Xylazine used as a sedative

Question 114

* What is the mode of action for a Barbiturates * What are some that we use * What would you not use Barbiturates for?

Answer 114

* Decrease CNS excitability via GABA Agonism. * Propofol (White Liquid that goes in vein), Alfaxalone * Dont use for Liver Failure or caesareans

Question 115

What is the difference between a poineer (innovator), generic and compounded drug?

Answer 115

* Pioneer drugs the company has spent $millions creating the drug, testing the drug and satisfying stringent regulatory requirements of safety, efficacy and manufacturing. Because of this they have a patent period of 10 years meaning no other company can copy the drug and sell it within that period meaning the price can be what ever the drug company wants. * Generic - company has spent 10s-100s of thousands of $ creating a copycat drug whose bioavailability has been proven to be within an acceptable range of the pioneer product (=bioequivalence). Payoff = ability to sell an expensive and/or high demand product at a cheaper price and therefore make some money by getting into a new market. * Compound - Company has not spent a significant amount of money to create an unregistered preparation of a drug whose bioavailability (and therefore bioequivalence) is unproven and therefore the safety and efficacy of the product is unknown. Pay off = freedom to create novel preparations that meet the doctors/dentists/veterinarians needs

Question 116

What drug could you use if your bitch had urinary incontinence? How does this work?

Answer 116

Phenylpropanolamine

Question 117

Describe the major organ responses of α1, α2 agonists

Answer 117

Question 118

What is cumulative anaesthetic ?

Answer 118

1. Dose 1 (give drug) anaesthesia occurs given the dose is high enough, then the anaesthetic wears off because lots of the drug has redistributed from the brain to the less perfused organs. 2. Dose 2 given while the animal is sedated / during anaesthesia (ie before dose1 has cleared the body) leads to anaesthesia which then takes longer to wear off because distribution away from the brain is slowed down by the blood having lots of drugs in it .

Question 119

What are the increased requirements for the safe use and dispensing of S8's

Answer 119

* Must live in locked Safe * Must keep a Register of Drugs of Addiction recording all incomings and outgoings, every dose is to be signed off by a Vet, Dr or dentist, Inventory to be done monthly, kept up to date and ready for unannounced spot audit by WA Health Dept

Question 120

Explain the Spectrum of activity

Answer 120

Question 121

How can administration frequency influence the efficacy of beta lactam antibiotics?

Answer 121

Beta Lactam antibiotics are time dependent bactericidals and for antibiotics of this class, efficacy is increased by maximising the lenght of time that the plasma concentration exceeds the MIC for the bacterium causing infection. This means by administrating beta lactams more frequently (eg TID compared to BID), efficacy is improved. Conversely administering the beta lactams less frequently decreases efficacy

Question 122

What are some clinical Applications of Corticosteroids

Answer 122

MANY * Replacement in adrenal insufficiency (Addisons = underactive adrenal cortex) * Induction = initiating Birth * Supraphysiologic to help with Ketosis * Supraphysiologic to suppress * Allergy - Atopy (=envrionmental skin allergies), insect bite hypersensitivity * Inflammation - General Inflammation (bandaid solution) * Immune Disease (eg autoimmune disorders) * Veterinary Dermatology * Ears * Indctions * Equine Airwaw Disease - Inhaland corticosteroidsAutoimmune Bleeding Disorders * Shock (DO NOT USE) as exaserbates the reduction in perfusion of extremities

Question 123

What are Schedule 8 drugs? Give some examples

Answer 123

Controlled Drug available for use but manufacturing, supply, distribution, possession and use restrictions apply. Prone to abuse and misuse. No public advertising. Sources - Pharmicist, veterinarian. Can only be prescribed by vets, Doctors, Dentists * Codeine (Highest Doses) * Ketamine * Methadone * Morphine * Alprazolam (xanax)

Question 124

Local anaesthetic lignocaine is very commonly used for ? & any contraindictations/ side effects ?

Answer 124

For Cow caesareans & stitch ups Stingy due to the aciditic to maintain its solubility

Question 125

Summerise Pharmacokinetics (ADME)

Answer 125

Question 126

What NSAIDS would we use for productions Animals (Cattle and Pigs) What NSAID can we use on Sheep?

Answer 126

* Flunixin * Old, Cheap Established WHP's * Tolfenamic Acid * Expensive but fewer side effects than Flunixin * Established WHP's * Meloxicam * Large Animal Prep with increased Concentration. * Fewer side effects * Phenylbutazone * Good analgesic for lameness pain * **NO ESTABLISHED WHP's** in production animals due to decreased and unpredictable drug clearance. 1. Buccalgesic / Meloxicam

Question 127

LA Proxymetacaine is commonly used for ?

Answer 127

Excellent topical LA for ocular examination

Question 128

The 3 main antibacterial Targets 1. Inhibitors of Cell Wall Synthesis 2. Inhibitors of DNA Synthesis and integrity 3. INhibitors of Transcription and Translation

Answer 128

1. Beta Lactams (Penicillins, Cephalosporins) 2. Sulphonamides, Flouoroquinolones 3. Aminoglycosides, Tetracyclines, Macolides

Question 129

What are Schedule 9 drugs? Give some examples

Answer 129

Prohibited Substance Illegal substance. only available for scientific/medical purposes and only once permission granted. Sources - street dealer (import/exporter), some chemical suppliers * coca leaf (cocaine) * Cannabis * Etorphine (Elephant Juice) * Herion

Question 130

What is a general anaesthetic ? What are the 2 main types of GA ? What does titrate mean in regards to GA ?

Answer 130

1. A generalised , reversible depression of the CNS , leading to a lack of perception from ALL senses. 2. Injectable & inhalant 3. Give drug until desired effect is achieved .

Question 131

Determine the factors that allow the maintenance dose rate to be converted into a practical dosing interval.

Answer 131

* Drug clearance - know the maintenance dose rate required (3mg/kg/hr). Real World * How quickly the plasma drug concentration decreases (half life) * Therapuetic window * Compliance

Question 132

Aminioglycosides 1. What is their Spectrum of Action? Pathogen and Bacteria 2. What is thier mode of action? 3. Are aminoglycosides Dose Depentent of Time Dependent? 4. What is their Post-Antibiotic Effect? (PAE) 5. Name some Aminoglycoside Toxicity's

Answer 132

Aminoglycosides 1. Gram -ves but good against staphyloccus spp, Not anaerobes. * Through cell membrane via oxygen-dependent transport system. 2. MOA = influx into bacteria --\> cause breakdown in protein synthesis --\> Bactercidal effect 3. Dose Dependent 4. Long PAE - Bactericidal after plasma concnetration \< MIC 5. Ototoxicity, Nephrotoxicity

Question 133

1. Who can request Drug compounding? 2. Who does the Compounding? 3. Who may use the compounded drug?

Answer 133

1. An authorised person e.g. doctor, dentist or veterinary surgeon via prescription. 2. prepared by a veterinarian or pharmacist 3. meet the specific medical needs of an individual patient.

Question 134

Describe what is meant by the term firstpass metabolism (2 marks).

Answer 134

This is where a drug is metabolised before it enters the systemic blood supply. This reduces the bioavailability of the administered drug. For example, the oral bioavailability of morphine is reduced due to pre-systemic hepatic metabolism

Question 135

Describe Parasympatholytic toxicity

Answer 135

Question 136

List the clinical uses of Clenbuterol and what adrenergic receptors it increases or decreases activity of.

Answer 136

Question 137

Name some Anti-Diarrhoeals

Answer 137

Diarrhoea is a sympton not a disease * Opiods (MOA - increased water retention and increased transit time) Loperamide (imodium), Diphernoxylate (Lomotil) * Kaolin (Scourban) - Clay that non-specifically absorbs everything. Production animals \>Horses\>Small Animals * Activated Charcoal

Question 138

Sulphonamides 1. What is the mode of action? 2. Are the Bactercidial or Bacteriostatic? 3. What is their spectrum of action 4. What is their toxicity? 5. What are some Sulphonamides

Answer 138

Sulponimides 1. Inhibit the synthesis adn conversion of folate (which must be synthesised by bacteria) 2. Bacteriostatic 3. Broad Spectrum - **Gram + & -** and coccidia (protozoa) 4. Toxicity * Hypersensitivity esp Doberman Pinschers - Hepatic Necrosis * Keratoconjuctivitis sicca (KCS = Dry eye) 5. Sulfadiazine, Trimethoprim, Silver Sulphadiazine (Flamazine)

Question 139

What are Schedule 7 drugs? Give some examples

Answer 139

Dangerous Poison High potential for causing harm specially regulated and only available to authorised users. Can only be purchased from specialised chemical suppliers * Strychnine * Fluoroacetate (1080)

Question 140

Mepivacaine (LA) is commonly used by vets for ? Benefit to the animal when using ?

Answer 140

Equine use for nerve blocks in lame horses Less irritating then lignocaine

Question 141

Name an antibiotic suitable for chlamydia in a bird

Answer 141

Doxycycline

Question 142

Corticosteroids are used at various doses depending upon what we are trying to achieve, what are some examples of this?

Answer 142

* Prednisolone in a dog * Anti-Pruritic (anity-allergy) = 0.5mg/kg/day * Anti-inflammatory - 1mg/kg/day * Immunosuppressive = 2mg/kg/day * Double it for cats Always try and use the lowest possible dose for your patient to minimise side effects

Question 143

Explain the difference between on label and off lable use

Answer 143

Off-Lable use is using the drug for a different species, at a different dosage recommendation (dose, route, frequency and duration) and/or a different purpose. The Safety and efficacy has not been proven for such off lable use.

Question 144

Where are most drugs eliminated from ?

Answer 144

Kidneys * removal of drug from the body is usually from the urine / kidney. * can be accelerated by diuresis * can be slowed by Kidney and Heart disease. * elimination is quantified by drug clearance.

Question 145

List the clinical uses of Salbutamol, Salmeterol and what adrenergic receptors it increases or decreases activity of.

Answer 145

Blue Inhalers

Question 146

Name the Adrenergic Antagonists and in atable what subclasses do they effect

Answer 146

Question 147

Macrolides 1. Bactercidal or Bacterioistatic? 2. Dose or Time dependent? 3. Spectrum of action 4. Mode of Action, Good for? 5. Name some

Answer 147

Macrolides 1. Bacteriostatic 2. Time Dependent 3. Gram +ves and select few Gram -ves (Pasteurella), Moderate to excellent anaerobic coverage 4. Macrolides get trapped in acidic environments eg abscesses, necrotic tissue, lungs, maststis, metritis, Bovine Respiratory Disease (BRD) 5. Tylosin (concentrates in milk), Tilmicosin (SC only - will stop heart if given IM, IV) not to be used in Dairy Cows, Tulathromycin (Respiratory disease and 12 week dosing interval) SC for cattle, IM for pigs.

Question 148

What are the 6 Mechanisms of Antibiotic Resistance?

Answer 148

1. Intrinsic resistance eg. aminoglycosides and anaerobes 2. Via a decreased permeability to the drug in the cytoplasmic membrane eg. some beta lactams and many gram -ves 3. Increased production of a drug-destroying enzyme eg. beta-lactamase 4. The target enzyme/protein is replaced by one with less affinity for the drug eg. altered penicillin binding protein in MRSA 5. Active extrusion of the drug via MDR P-glycoprotein pump eg. Pseudomonas spp. 6. Biofilms provide a barrier to host's immune system and many antibiotics. Biofilms occur at solid-liquid interfaces eg. Bladder wall, Joints, IV Catheters, ear canals

Question 149

Explain Positive-Controlled

Answer 149

Is a compound that is widely accepted to have efficacy for a desired effect.

Question 150

Name an α₁ antagonist and the clinical uses

Answer 150

Question 151

What NSAID's would be used for a dog and why?

Answer 151

* Cox-2 selective NSAIDS - coxibs * Firocoxib "Previcox" * Dogs - Oral * Robenacoxib "Onsior" * Dogs and Cats - Impressive Feline palatability * Mavacoxib "Trocoxil" * Dogs * Dosing regime: Dose on day 1, 2 weeks later then monthly for 5 months, then one month off. (But can use other NSAIDs during rest period.

Question 152

What is the most important thing you need to do/get before prescribing this for your patient?

Answer 152

Make sure the owner or patient has provided INFORMED consent – beware of “the vet never told me that a registered version of this drug already existed” – beware of “whatever you say doc” ≠ informed

Question 153

What are some Common and Sporadic glucocorticoid side effects seen in the Early and Late stages of use?

Answer 153

EARLY (Days-Weeks) * Common * Polyuria and Polydipsia (ADH inhibition) * Mood Change * Euphoria/Dysphoria * Weight Change (PP=Polyphagia) * Catabolic State * Transient adrenal suppression * HPA suppression * Sporadic * Peptic Ulcer * Decreased Mucosal blood flow LATE (Months-Years) * Common * Central obesity * Redistribution of fat * pendoulous abdomen * Hair Loss * Prolonged adrenal suppression * HPA Suppression * Sporadic * Cataracts/Diabetes * Sugar levels too high in blood. Sugar deposits in lens and renders it opaque * Hypertension

Question 154

What are Schedule 2 drugs? Give some examples

Answer 154

Pharmacy Medicine Safe use may require advice from a pharmacist. * Asprin (\<= 325mg\*, \<=500mg\*, \<=625mg\*) * ibuprofen (\<=200) * Paracetamol (\<=500mg\*, \<=1000mg\*) \* depending on pack size

Question 155

1. What are the 2 phases of drug metabolism? 2. What is the purpose of Drug metabolism?

Answer 155

1. 2 Phases of drug metabolism are 1. Phase I (the P450 enzymes) 2. Phase II (usually through glocuronidation) 2. The biotransformation of a lipophilic compound into a more hydrophilic compound in order to facilitate elimination. The more hydrophilic metabolite can be eliminated by the kidney more easily Phase II Metabolism deficiencies - Feline : Slow with some of the (not all) glucuronidation pathways

Question 156

What is Post-Antibiotic Effect (PAE)

Answer 156

Persistent suppression of bacterial growth after removal of the antimicrobial agent. Theories * Drug persistence * Synthesising enzymes prior to replication/slow recovery to non-lethal damage

Question 157

What are Schedule 0 drugs? Give some examples

Answer 157

Uncontrolled Products, Chemicals used in childrens chemistry sets, most cosmetics, mosquito control, matches.

Question 158

What are Schedule 4 drugs? Give some examples

Answer 158

Prescription only medicine (peo ple) or Prescription animal remedy (animals) Use and Supply only by permitted persons, Can be dispensed by pharmacist through a prescription. NO PUBLIC ADVERTISING Sources - Pharmacist, veterinarian. Can only be prescribed by vets, doctors, dentists * Asprin (if with paracetamol) * Codine (\<=30mg) * Paracetamol (Slow-Release or \>=500mg\* or \>=1000mg\*) \* depending on pack size

Question 159

Explain Double Blinded

Answer 159

A double-blind study is one in which neither the participants nor the experimenters know who is receiving a particular treatment. This procedure is utilized to prevent bias in research results. Double-blind studies are particularly useful for preventing bias due to demand characteristics or the placebo effect.

Question 160

What are the clinical uses of Atrophine

Answer 160

* Anaesthesia - * • primarily acts on HR. No effect on vascular tone; minimal effects on myocardial contractility • used for reversing intraoperative bradycardia • still used in private practice as a preanaesthetic medication to attempt to diminish the CVS depressant effects of some of the anaesthetics and sedatives. This is no longer recommended * Atrophine for methiocarb toxicity * because atropine is an antimuscarinic it can be used to treat the muscarinic side effects of OP/methiocarb toxicity – i.e. vomiting, diarrhoea, lacrimation, salivation, bradycardia etc – dose conservatively: too high a dose will stop the GIT and prolong the residence time of ingested toxins • but because it’s not an antinicotinic the nicotinic effects will remain unchecked and other treatments are used for these side effects – i.e. muscle tremors • there are also central CNS excitation signs to worry about e.g. seizures * Opthalmology * commonly used as a cycloplegic (ciliary muscle paralysis to relieve ciliary spasm) – part of the pain of a corneal ulcer is from ciliary muscle spasm • will cause mydriasis for 1-3d+! – beware of subsequent retinal damage • for the ophthalmological examination of the retina, a mydriatic is needed but atropine should not be used for this purpose because the effects last too long • contraindicated for glaucoma – a consequence of mydriasis is closure of the aqueous drainage channels -\> intraocular pressure (IOP) will increase and glaucoma will become worse

Question 161

Explain the difference between Statistically significant and clinically significant

Answer 161

Results are said to be "statistically significant" if the probability that the result is compatible with the null hypothesis is very small. ... Clinical significance, or clinical importance: Is the difference between new and old therapy found in the study large enough for you to alter your practice?

Question 162

What are Schedule 3 drugs? Give some examples

Answer 162

Pharmacist only Medicine requires advice from pharmacist. No prescription needed. * ibuprofen (\<=400mg) * some paracetamol-ibuprofen combinations Combination drugs are scheduled according to the highest scheduled active

Question 163

Define Pharmacokinetics

Answer 163

The study of the movement of drugs within the body and encompassing absorption, distribution, metabolism and elimination =ADME WHAT THE BODY DOES WITH THE DRUG

Question 164

Define Pharmacodynamics

Answer 164

The study of the pharmacological response to the drug WHAT THE DRUG DOES TO THE BODY

Question 165

Alfaxalone is a GABA _________ ? Does alfaxalone have a cumulative effect ? Does it have an analgesia effect ? Given IV or IM ? Alfaxan-CD RTU means ?

Answer 165

Agonist. smooth induction of anaesthetic No cumulative effects -& can be used to provide top ups . some analgesia -but limited evidence IV vastly better than IM , extrvasation stings but doesnt cause tissue sloughing Alfaxalone cyclodextran ready to use.

Question 166

1. What is the TOxicity of Beta Lactams? 2. Side effects of Beta Lactams?

Answer 166

1. Very Safe, can be used in geriatrics, juveniles, pregnancy and during lactation 2. Usually come about through dysbiosis * Killing good bacteria, recolonisation by a monomorphic population, toxin, GIT signs * Diarrhoea, vomiting most common * small herbivores * Accidental IV with some preperations ALLERGIES Seems to be only a human problem only.

Question 167

Discuss how pharmacogenetics can affect drug efficacy and safety?

Question 168

What are some reason why you would use a nerve block?

Answer 168

* Cow Caesarean - Inverted L-Block, Paravertebral never block * Epidural - Calvings, Cruciate surgeries * Dehorning * Stitchups under Local * Intravenous Regional Analgesia (IVRA) - Digit amputation MUST use a torniquet * Peripheral Nerve Blocks - Blocking out entire regions of the leg * Topical anaesthesia - third eye lid * Regional Anaesthesia - Dental Blocks

Question 169

Describe the role that ACh plays in the peripheral nervous system (sympathetic, parasympathetic and somatic) and describe the effects that ACh has on the major organs/systems

Answer 169

Acetylcholine will activate all :- * Nicotinic and Muscarinic receptors in the Parasympathetic Pathway * Nicotinic receptors at the ganglion of the sympathetic pathway * Nicotinic receptors on the skeletal muscle of the somatic nervous system

Question 170

Describe why extemely large burdens of ascarids should be treated in a cautious manner?

Answer 170

AScardis are large worms and incredibly high numbers can be found infesting a single animals intestine. If an anthelmintic is chosen that has high efficacy against the ascarid in question, mass ascarid die offs can cause verminous impactions in the gut .

Question 171

List two antibiotics that would be suitable as an emprical selection for sepsis in a foal

Answer 171

A beta-lactamase resistant beta lactam and an aminoglycoside. Eg amoxycillin-clavulanic acid & Gentamicin. This will provide broad spectrum Coverage with the ammoxycillin-clavulanic acid targeting the Gram +ve aerobes and Gram +ve and -ve anaerobes, while gentamicin will target the gram -ve aerobes

Question 172

Bactericidal Antibiotics can be divided into 2 groups what are they?

Answer 172

* Time Dependent Killers - Duration of time (at any concentration beyone MIC) determines how many bugs are killed * Dose Depentent Killers - The difference between the drug concentration and MIC determines how many bugs are killed eg. AUC:MIC, C_max:MIC (=IQ)

Question 173

Pentibarbitone primary use is ? How is it used ? What colour is the solution ? Any other effects ?

Answer 173

Euthanasia solution give an IV overdose quickly to euthanase the animal high concentration preparations contain green dye dont use in liver failure or caesareans.

Question 174

Name an NSAID that is registered for use in a cat.

Answer 174

Meloxicam

Question 175

* Explain the Mode of Action of NSAID's * What are the two isoforms?

Answer 175

* Inhibits Coclooxygenase 1 & 2 which reduces inflammation. * Cox 1 (Constitutive) - Aways working to produce house keeping products with numerous protective roles. In blood vessels, Gastrointestinal mucosa and kidney PGE₂ PGI₂ * Cox 2 (Induced) - Induces after an insult (trauma etc) to produce the mediators of inflammation, pain and pyrexia

Question 176

Inhalant GA are described as ? What are the driving inputs of a gas anaesthesia ? Name some inhalant GA formulations ?

Answer 176

1. drugs that are given and largely remove using the lungs 2. Oxygen, anasethetic gas which is an anaesthetic liquid converted into a gas by a vaporiser. 3. Halothane, Isoflurane, Sevoflurane.

Question 177

What does Parasympathomimetics mean? List the Major Parasympathomimetics drugs and their clinical uses

Answer 177

* Parasympathomimetics = Muscarlinic Agonist * Bethanecol

Question 178

Compare the following four agonists to each other using the following criteria: Full v Partial agonist and realitve potency

Answer 178

* A = full agonist (assuming plateaus at maximum response), 2nd most potent * B = partial agonist, most potent * C = full agonist (assuming plateaus at maximum response), 3rd most potent * D = full agonist (assuming plateaus at maximum response), least potent

Question 179

List the things that the Parasympathetic chain of the Autonomic Nervous System controls

Answer 179

Rest and Digest

Question 180

Aminoglycosides ## Footnote Name some Aminoglycosides, what animals, Spectrum.

Answer 180

* **Gentamicin**, Horses, Broadening Spectrum (combine with Beta-Lactams), Banned in Food producing animals * **Amikacin**, Less resistance and safer than Gentamicin, VERY EXPENSIVE * Neomycin/Streptomycin - Went out with the ark

Question 181

Graph the difference between Time dependent and Dose Dependent Bactericidals

Answer 181

Question 182

Name an antibiotic suitable for pneumonia in a feedlot cow.

Answer 182

ANy one of : tylosin, timicosin, oxytetracycline, florfenicol, ceftiofur

Question 183

Using your knowledge of the physiology of acid secretion in the stomach, discuss why the proton pump inhibitors are the strongest medicaitons for treatment of gasteric ulceration

Answer 183

There are various stimuli that all result in acid being secreted into the stomach eg. neurocrine (acetylocholine), pancrine (histamine) and endocrine (gastrin). Proton pump inhibitors are the most effective anti-ulcer medications because they will stop the release of acid into the stomach irrespective of the initiating cause. All other anti-ulcer medications are limited to more specific causes of acid secretion in the stomach

Question 184

If we were treating Addisons Disease what groupd of corticosteroids would we use?

Answer 184

Addisons disease (= adrenal cortex insufficiency = hyperadrenocorticism) is more specifically a deficiency in **Mineralocorticoid** production more than it is a deficiency in glucocorticoid production. Therefore with replacement therapy we usually select a corticosteroid with *preferential* affinity to, and efficacy at, the mineralcorticoid receptor. eg ***flurocortisone*** Each Corticosteroid has a unique "Spectrum" of activity * Most are more efficacious at the glucocorticoid receptor * Some are more effacious at the mineralcorticoid receptor * Others are equal

Question 185

Discuss how glucocorticoids can have both hyperadrenocorticism and hypoadrenocorticism as adverse side effects?

Answer 185

Exogenous glucocorticoids (ExGC) will mimic the effects of endogenous glucocorticoids (EnGC) and so if excessive amounts of ExGC are administrated, the effects will be indistinguishable from the adrenal gland disease wehre excessiver amounts of EnGC are produced hyperadrenocorticism. ExGC will also act to negatively feedback on the release of Corticotropin-Releasing-Hormone (CRH) and Adrenocorticotropic hormone (ACTH) from the hypothalamus and the pituitary gland respectively. This results in a decrease in the production of EnGC. If the exogenous administration of GCs stops suddenly, the body will not have adequate amounts of GC for normal body functions. This disease is called Hypoadrenocorticism.

Question 186

List an advantage that an inhalant offers over an injectable agent during induction of general anaesthesia?

Answer 186

Mask induction does not require the animal to be injected and considering most injectable general anaesthetics should be given intravenously, mask induction will nearly always be technically easier.

Question 187

What is the Mode of Action for "the Chondroproctives" Polysulfated Glycosaminoglycans (Adequan, Cartrophen)

Answer 187

* Stimulates synovial fibropblases to produce hyaluronic acid * Inhibition of inflammatory mediators (eg proteases, collagenase) * Improves subchondral blood flow. Used for Horses and Canine osteoarthritis

Question 188

What effect would excessive ACh cause?

Answer 188

Overstimulation of the parasympathetic nervous system and the somatic nervous system and maybe even the CNS

Question 189

* What happens when we suddenly stop cortisone? * Why would this happen?

Answer 189

* Potentially get a hyperadrencortical crisis * Exogenous Glucocorticoid eg cortisone (tablets) drive the **negative** feedback loop meaning if you suddenly stop them there potentially wont be enough cortisol resulting in a hypoadrenocorticalism (addisons) episode

Question 190

1. Ketamine is a GA what is its mode of action ? 2. Ketamine is also known as a _________ anaesthetic? 3. How is it best administrered?

Answer 190

1. Highly complex , part of MOA is antagonist at NDMA receptors (N-Methyl D-aspartatea glutamate receptor) on excitory neurons. 2. Disassociative anaesthesia - patient is grossly unresponsive to the environment , yet not asleep. 3. Good non-IV bioavailability, non IV injections sting, capable of inducing GA when given IM or SC.

Question 191

What is the advantage on an inhalant over an injectable GA during an induction ?

Answer 191

* mask induction does not require the animal to be injected . considering most injectable GA are IV administration, mask induction will nearly always be technically easier. * Maintenace with inhalant is easier than injectable. * Injectable is quick to induce