Therapeutics for the MSK System Flashcards
What are benzodiazepams used for?
Used as part of the pre-anaesthetic or sedation protocol as muscle relaxants
What are NMBA’S Used for?
Used to induce paralysis – small rapid moving muscles
(eyes, larynx) relax before limbs and trunk
What are non-depolarising agents?
- ACh antagonists which produce motor paralysis
- Can be reversed using anticholinesterases e.g.
neostigmine, pyridostigmine
What are depolarising agents?
ACh receptor agonists – not metabolized by
acetylcholinesterase –> end plate cannot
repolarize
* Cannot be reversed
What is a ryanodine receptor antagonist?
dantrolene - blocks
release of Ca2+ ions from sarcoplasmic reticulum in striated
muscle preventing muscle contraction
What is a ryanodine receptor used to treat
Used to treat recurrent exertional rhabdomyolysis in horses
* Historically used to treat malignant hyperthermia (a
runaway contraction of muscle which was a complication
with older volatile anaesthetics e.g. halothane).
What are intra articular glucocorticoids used for?
Intra-articular glucocorticoids (e.g. methylprednisolone,
triamcinolone) used to treat inflammatory musculoskeletal
conditions (esp. horses)
What is the benefit of COX 2?
Selective NSAIDs mainly reduce GI side effects. The
frequency of other AEs such as emesis, lethargy and death is
not significantly different
What are the adverse effects of NSAIDS?
GI (nausea and vomiting, gastric & intestinal damage
with risk of bleeding and ulceration)
* Reversible renal insufficiency – avoid in dehydrated
patients and in patients on potentially nephrotoxic
drugs – monitor renal function
* Small risk NSAIDs may precipitate cardiac failure in
animals with cardiovascular disease
What is grapipant?
Non-steroidal, non-cyclooxygenase inhibiting antiinflammatory drug
* Selective antagonist of the EP4 receptor
* The EP4 receptor is important in mediating pain and
inflammation as it is the primary mediator of the
prostaglandin E2-elicited sensitization of sensory neurons
and prostaglandin E2-elicited inflammation
What is the side effect of grapipant?
soft faeces/diarrhoea, vomiting) are generally
transient
What is the function of pentosan polysulfate?
is indicated for treatment of lameness and pain of degenerative joint disease/OA in dogs
What is pentosan polysulfate?
Semi-synthetic polymer with anti-inflammatory properties –
reduces metalloproteinases thereby preserving proteoglycan
content and protecting cartilage matrix from degradation
What is a neutraceutical?
Nutritional supplements for normal body structure and
function with the intent of improving health and well-being
What is Bedinvetmab?
Nerve growth factor (NGF) increases inflammatory mediators
and stimulates nociceptors
What is paracetamol?
First line pharmaceutical treatment for OA in humans
* NSAID with analgesic and antipyretic but weak antiinflammatory
* MoA not clear - seems to have specific activity for the CNS COX
enzyme, COX3 (few GI effects). It may also reduce conduction
in pain sensory neurons (action through TRPA1 ion channel).
* Careful with the dose in dogs – no veterinary product licenced
for dogs. DO NOT USE in cats.
What is tramadol?
Centrally acting analgesic with complex mechanism of action
involving opioid, norepinephrine, and serotonin receptors
* Unlike morphine, tramadol does not have depressing
effects on respiration or gastrointestinal motility
What is gabapentin?
Analogue of the neurotransmitter GABA. Initially used as an
antiepileptic, now used in the treatment of neuropathic pain
* MoA of its analgesic effect is unknown
* Start with a low dose and increase slowly. May cause
mild sedation and ataxia
* Withdraw therapy slowly too (potential for rebound pain
shown in humans)
What does tissue injury provoke?
Provokes a response that involves the release of inflammatory mediators
What do inflammatory mediators trigger?
- they trigger nociceptors
- pain signal is then transmitted along different axons
- blocking of transmission
- pain is perceived in the CNS
What do glucocorticoids inhibit in the arachidonic acid cascade?
- Phospholipase A
- therefore the production of arachidonic acid
What do NSAIDS inhibit in the arachidonic acid cascade?
- Cyclo-Oxygenase
- therefore no prostaglandins produced
What does COX-1 produce?
Arachidonic acid with homeostatic functions
What does COX-2 produce?
Arachidonic acid with inflammation functions
(expressed in inflammatory cells)
What does Grapipant inhibit?
PGE 2 (prostaglandins 2)
What are the GI side effects of grapiprant?
GI side effects (soft faeces/diarrhoea, vomiting) are generally transient
What is NaPPS indicated for?
for treatment of lameness and pain of degenerative joint disease/OA in dogs
What is NApps/ Pentosan polysulphate given as?
Given as a course of 4 weekly sc injections
* Response variable
* Duration of effect variable – max 3 courses of 4 injections
in 12 months
* Concurrent use with steroids and NSAIDs
contraindicated (risk of bleeding due to
combined effects on platelet aggregation)
What nutraceuticals are used for normal body structure?
Multiple substances commonly used in arthritis, all have
variable and incomplete evidence for efficacy
* Chondroitin sulfate – component of cartilage
* Glucosamine – component of cartilage
* Antioxidants – counter potentially damaging oxidants
* EFAs – weak anti-inflammatory properties
What is bedinvetmab?
a canine monoclonal antibody (mAb) and
frunevetmab is a felinised mAb targeting NGF
What is bedinvetmab used for?
Long term management of OA pain
do not use in young animals under 12 months- critical role in development
there is also limited long term data
What is the MoA for paracetamol?
- Unclear
- may reduce conduction in pain sensory neurons
- should not be used in cats
What is the function of tramadol?
Centrally acting analgesic with complex mechanism of action
involving opioid, norepinephrine, and serotonin receptors
* Unlike morphine, tramadol does not have depressing
effects on respiration or gastrointestinal motility
What is tramadol used to manage?
Management of mild to moderate acute pain, but also as
adjunctive analgesic in management of chronic arthritic pain
* Effects may be variable
* Sedation at high doses, dysphoria more likely in cats
* Can be combined with other classes of analgesic
Why might you need to withdraw gabapentin slowly?
Potential for rebound pain
What is amantadine commonly used for?
multimodal treatment for progressive moderate to severe OA pain and for pain relief in osteosarcomas
