NSAIDs Flashcards
What is the importance of mananging chronic pain?
- it is maladaptive and of no benefit to the animal
- pain comprises the sensory discrimination aspect being processed by the brain and then interpreted with both physical and emotional components
- pain is a welfare issue
What is the definition of pain?
nociceptive or neuropathic
What is nociceptive pain?
originating in the tissues that are not in the nervous system
What is neuropathic pain?
pain that originates in the tissues in the nervous system
Which conditions can have a combination of neuropathic and nociceptive pain?
chronic pain conditions such as osetoarthritis and cancer
What patients will you see with neuropathic pain?
those that have direct damage to the nervous system
What happens when nerves are damaged?
cholecystokinin is released
What happens when cholecystokinin is released?
it antagnoises opioid mediated analgesia meaning opioids are less effective
How do NSAIDs work?
by inhibiting prostaglandin production from arachidonic acid by inhibiting to clycooxygenase (COX) enzyme
How do NSAIDs affect leukotriene production?
inhibits lipoxygenase enzyme
What is the newest NSAID grapiprant?
non-cyclooxygenase inhibiting anti-inflammatory drug
What does grapiprant act as?
selective antagonist of the EP4 receptor
What is the EP4 receptor?
a key prostaglandin E2 receptor that predominant mediates prostaglandin E2-elicited nociception
Where do most NSAIDs work?
the periphery
Where can some NSAIDs act?
centrally in the dorsal hron by inhibiting COX
What are the adverse effects associated with NSAID administration in relation to?
- protective function that prostaglandins have in the body
- how easily the NSAID can leave the circulation and cross into the tissues
How can prostaglandins be divided?
constitutive or ‘housekeeping’
What functions to the contitutive prostaglandins have?
protective ones which can be blocked by NSAIDs
What enzymes are produced by constitutive prostaglandin production?
COX-1 isoenzyme
What enzyme is produced by inducible prostaglandin production?
COX-2 isoenzyme
Which drugs are non-specific and block COX-1 and COX-2?
older NSAIDs such as aspirin and flunixin
What do meloxicam nad carprofen block?
COX-2
What are prostaglandins essential for in the GI system?
- maintenance of mucosal blood flow
- bicarbondate and mucous secretion
- epithelialisation
What GI signs can NSAIDs lead to?
ulceration and bleeding
What do prostaglandins regulate in the renal system?
- glomerular filtration rate
- renin release
- sodium excretion
What can blockage of the vasodilatory prostaglandin lead to?
decreased glomerular filtration rate at times of low circulating blood volume
What can NSAIDs lead to in the renal system?
- water retention and oedema
- hypertension
- may impair glomerular filtration in patients with renal disease or hypotension
- may cause renal ischaemia in patients with hypotension
What do NSAIDs induce in the hepatic system?
liver enzyme
What central nervous syem reaction might you see in cats after NSAID administration?
idiosyncratic dullness and lethargy
How long do newer NSAIDs prolong markers of blood clotting ifgiven for long courses?
30-90 days
How do you reduce the risk of side effects when NSAIDs are administered chronically?
- do not exceed licensed dose
- do not give two NSAIDs concurrently
- do not give NSAIDs and corticosteroids concurrently
- do not give NSAIDs to animals that are hypotensive/dehydrated
- warn owners about risks of NSAIDs
- think about the animal as an individual
Why is it important to give NSAIDs wirth food?
- GI ulceration can occur but more common if the pet already has it
- should always be given with food unless contra-indicated
What side effects should you warn owners about to look out for?
- vomiting and diarrhoea
- signs of blood in faeces
- fullness
- anorexia
What are the possible causes of hypotension due to NSAID animinstration?
- concurrent disease with vomiting and diarrhoea
- trauma with blood loss or shock
- pets that stop eating and/or drinking
When are side effects more likely to occur?
in the first 2 weeks of therapy
When should re-checks be done after prescribing NSAIDs?
1-2 weeks after starting treatment
