Analgesic Agents: non-opioids Flashcards

1
Q

At what point along the neural pathway do NSAIDs target?

A
  • At the Nocicepter itself: working locally to reduce the inflammatory ‘soup’, and thus reduce the speed of TRANSDUCTION and magnitude
  • At the spinal cord: to alter MODULATION
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

At what point along the neural pathway do Local anesthetics target?

A
  • At the Nocicepter itself: working locally to reduce the inflammatory ‘soup’, and thus reduce the speed of TRANSDUCTION and magnitude
  • At the peripheral nerves: thus reducing TRANSMISSION of signals
  • At the spinal cord: to alter MODULATION
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

At what point along the neural pathway do NMDA antagonists target?

A
  • At the spinal cord: to alter MODULATION
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

At what point along the neural pathway do alpha1 agonists target?

A
  • At the peripheral nerves: thus reducing TRANSMISSION of signals
  • At the spinal cord: to alter MODULATION
  • At the brain: to alter PERCEPTION and promote the descending inhibitory pathways of pain
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the roles of PGE2, PGF2 and PGD2?

A
  • Pro-inflammatory: tissue edema, swelling and redness
  • Increase perception of pain
  • Induce Fever
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the roles of PGI2?

A
  • Inhibition of coagulation

- Decrease platelet aggregation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the roles of Thromboxanes?

A
  • Stimulate coagulation

- Increase platelet aggregation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the roles of COX1 and COX2?

A

COX1: produce substances important for normal homeostasis. Turn AA into Thromboxanes

COX2: produces inflammatory mediators. Turn AA into PGI2 and PGE2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Where in the body are NSAIDs metabolized and excreted?

A

Metabolized: Liver, via glucuronidation

Excretion: Urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

The duration of action of NSAIDs is dependent on the ability of glucoronidation in the liver, which species have a better and which species have a limited ability to undergo glucuronidation?

A

Better: Donkeys- therefore require more frequent dosing

Limited: Cats- therefore toxicity is more likely

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the main effects of NSAIDs?

A
  • Anti-inflammatory (locally)
  • Analgesic (local and systemic)
  • Antipyretic
  • Anti-endotoxic
  • Anti-thrombotic
  • Anti-spasmodic
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the side effects associated with NSAIDs?

A
  • Vomiting, diarrhea
  • Anorexia
  • Abdominal pain
  • GI ulceration
  • Predispose kidneys to injury by inhibiting PG, and thus vasodilation cannot occur in response to reduced renal blood flow
  • Increased clotting time
  • Predictable Intrinsic hepatic toxicity
  • Unpredictable Idiosyncratic hepatic toxicity
  • Can cause abortion and fetal malformations

caution: in horses, they are associated with right dorsal colitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the contra-indications to using NSAID’s in a patient?

A
  • GI Disease
  • Impaired hepatic or renal function
  • Dehydration/ hypovolemia/ hypotensive
  • Coagulopathies
  • Receiving other NSAIDs or corticosteroids
  • Pregnant or lactating
  • Neonates (< 8weeks old)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How can NSAIDs be classified?

A
  • Based on Physiochemical properties

- According to their action on COX

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the Non-selective NSAIDs? (3)

A

Phenylbutazone aka “bute”
Flunixin
Ketoprofen: licensed for use in pigs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are the COX-2 selective NSAIDs? (3)

A

Meloxicam (Metacam)
Carprofen (Rimadyl)
Robenacoxib (Onsior)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the dual inhibitor NSAID? (1)

A

Tepoxalin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the 9 considerations before administering NSAID’s?

A

1) obtain complete history and previous use of NSAIDs or steroids
2) Assess patient: dehydration, cardiac, hepatic and renal dysfunction
3) Provide verbal and written client instructions
4) Recognize side effects and withdraw treatment
5) Perform regular hepatic and renal tests to assess toxicity/ damage
6) Use a balanced, integrated analgesic approach
7) Consider washout periods when changing drugs (7 day or more washout period)
8) Use gastroprotectants
9) Optimize the dose- titrate to the lowest effective dose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How long MUST the washout period be before using NSAIDs on an animal that was given Aspirin?

A

10 days from last dose

This is why it is not recommended owners treat with Aspirin at home, as NSAIDs cannot be used for 10 days

20
Q

What species is Phenylbutazone used in?

A

Horses: for acute pain

21
Q

Can Phenylbutazone be used in food-producing animals?

A

No! It is illegal in animals intended for human consumption

22
Q

What species is Flunixin meglumine used in?

A

Horses:

  • Analgesic especially for colic pain
  • Anti-inflammatory
  • Anti-endotoxic
23
Q

What species is Meloxicam used in?

A

Licensed for use in dogs, cats, horses, cattle: chronic pain management

note: specific dose for cats due to their reduced ability for glucuronidation

24
Q

What species is Carprofen used in?

A

Dogs, cats, horses

note: cats have a longer elimination half life

25
Q

What species is Robenacoxib used in?

A

Dogs and cats

26
Q

What species is Ketoprofen used in?

A

Pigs only

27
Q

What are the properties of Paracetamol/ Acetaminophen?

A
  • Analgesic

- Antipyretic

28
Q

A dog is showing signs of pain, along with vomiting and diarrhea. What NSAID or NSAID-like agent might be prescribed in this situation?

A

Paracetamol/ Acetaminophen (Perfalgan). Commonly known as Tylenol
It is considered to be as good as meloxicam, but does not cause the v/d side effects like meloxicam can

29
Q

Can Paracetamol/ Acetaminophen be used in cats?

A

No, never!
Because Paracetamol/Acetaminophen is metabolized in the liver through glucuronidation, along with the limited ability of the cat to undergo glucuronidation, their systems can be easily overwhelmed and toxicity is reached exponentially quicker

note: a cat sniffing the dust of Paracetamol/ Acetaminophen can cause toxicity

30
Q

How can Paracetamol/ Acetaminophen toxicity be treated?

A
  • Acetylcysteine, also known as N-acetylcysteine (NAC)

+ Ascorbic acid (Vit C)

31
Q

What species can Gapiprant be used in ?

A

Dogs: analgesic and anti-inflammatory for the treatment of OA

32
Q

What are the side effects associated with Gapiprant?

A

Vomiting, BUT no GI ulceration

and vomiting resolved if treatment is continued

33
Q

What species can Gabapentin be used in?

A

Dogs, cats and horses: anti-epileptic and for management of neuropathic pain
Cats: pre-clinical sedative

34
Q

How does Gabapentin work?

A
  • Blocks Ca++ gated channels on neurons, and stops the opening of excitatory channels
35
Q

What are the side effects associated with Gabapentin?

A

None are currently reported, even cardio and resp systems

Though its possible to see sedation + ataxia

36
Q

What species can Amitriptyline be used in?

A

Dogs: behavioural
Cats: behavioural and FLUTD
Horses: chronic laminitis

37
Q

What type of drug is Amitriptyline?

What is it commonly used to treat in dogs, cats and horses?

A

Its a tricyclic antidepressant

  • Behavioural disorders
  • Feline Lower Urinary Tract Disease
  • Neuropathic pain
  • Chronic laminitis (horses)
38
Q

How does Amitriptyline work?

A

Its a selective serotonin reuptake inhibitor (SSRI)

- It works to increase levels of serotonin and noradrenaline, and thus improve descending pain control

39
Q

What are the side effects associated with Amitriptyline?

A

CVS: Tachycardia and fatal ventricular tachycardia

  • Hypersalivation
  • Vomiting
  • Weight gain
  • Sedation
  • Serotonin syndrome (when given with drugs like Tramadol or Amantadine)
40
Q

How does Ketamine work?

A

Mu antagonist
Kappa agonist
It is an NMDA receptor antagonist: prevents calcium entry into the cell and therefore prevents excitatory signals from being transmitted to the brain
Dissociative anesthetic agent

41
Q

In what patients would Ketamine be contra-indicated?

A

Animals in shock or are moribund, it can cause cardiovascular depression likely due to prevention of Calcium entry into the cells, and can lead to cardiac arrest

42
Q

What are the uses of Amantadine?

A
  • Chronic pain management
  • Arthritis (especially when combined with meloxicam)
  • Neuropathic pain (e.g. limb amputation)
43
Q

How does Amantadine work?

A

It is a dopamine agonist, and an NMDA antagonist and possible local anesthetic properties via Na+ channel blockades

44
Q

What are the risks associated with Amantadine?

A
  • Serotonin Syndrome, especially if combined with Tramadol or Amitriptyline
45
Q

What is Serotonin Syndrome?

A

A group of symptoms attributed to high levels of Serotonin circulating in the body
Signs include:
- Changes in conscious state: anxious, restless +/- seizures
- Autonomic dysfunction: hypertension, tachycardia and hyperthermia
- Neuromuscular signs: muscle rigidity and tremors

46
Q

What are the roles of Serotonin?

A
  • platelet aggregation
  • vascular tone
  • neurotransmission
  • GIT motility
  • mood regulation
  • CVS function
47
Q

What is the treatment of Serotonin Syndrome?

A
  • Gastric lavage (if ingested)
  • Discontinue all serotonergic meds
  • Supportive care: control seizures, tachycardia and hypertension. Control seizures with a benzodiazepine