Test 3: 38 pain 2 Flashcards
opioids will cause — of the 2nd order neuron and — of the 1st order neuron
hyperpolarization (↑ K conductance)
inhibit NT (inhibit Ca channels)
— are effeective at modulating pain but do not prevent the generation of noxious stimuli
opioids
3 sites of action for opioids
peripherally, spinally, supraspinally
opioids act on what in the pain pathway
transduction, modulation and perception
DOES NOT work on translation
tramadol is what kind of med and causes what
full opioid agonist (M1)
also inhibits reuptake of serotonin and norepinephrine
mechanism of NSAIDS
- Inhibit COX production of proinflammatory molecules from arachidonic acid pathway
- Prevents the generation of noxious stimuli
- Effective when inflammation is a major component of pain
side effects of NSAIDS
Cox 2 selective – less side effects
- GI side effects – vomiting, diarrhea, ulceration
- Increase bleeding during surgery
- Renal injury
- Idiosyncratic hepatic necrosis reported in dogs
Grapiprant (Galliprant) – blocks specifically — receptor
EP4 prostaglandin
OA treatment for dogs
which part of pain pathway does NSAID work
transduction
modulation
how does local anesthetics work
completely block the transmission of pain
- Reversible neuronal conduction blockade by Na+ channels
- reduces MAC
- May have anti-inflammatory effects by inhibiting proinflammatory mediator release and altering proinflammatory mediator activity
- Reduce free radical formation
local anesthetics work on what parts of the pain pathway
transduction, transmission, modulation
⍺2 agonist work in the
CNS (pain relief)
also CV, respiratory, endocrine, GI and urogenital
⍺2 agonists work on what part of the pain pathway
transmission, modulation and perception
xylazine- large animal
dexmedetmidine- small animal
Atipamezole (reversal)
supraspinal analgesia,
peripheral: vasocontraction, ↑BP, reflex ↓HR.
Central: ↓SYMP, ↓BP, ↓HT
can ↓CO by 50%!
what is a NMDA antagonist med
ketamine at low dose
how do NMDA antagonist work
NMDA receptors are activated to process pain, can ↑ 2nd messangers → central sensitization
ketamine at low dose will block NMDA receptor, good for acute, chronic, neuropathic, cancer and burn pain
more effective for somatic than visceral pain
prevents wind-up/hyperalgesia if preemptive used
NMDA antagonists work on what parts of the pain pathway
modulation- dorsal horn of spinal cord
might work supraspinally in the limbic and thalamocortical systems
oral NMDA antagonist
Amantadine
how do sedatives effect pain
not analgesic
but reduce anxiety and stress
Phenothiazines: acepromazine
benzodiazepines: diazepam, midazolam
corticosteroid side effects
Polyuria/polydipsia, GI ulceration, iatrogenic Cushing’s disease
corticosteroids work on pain by
Anti-inflammatory drugs
Peripherally inhibit inflammatory cascade
how does gabapentin and pregabalin work
do not act on GABA receptors
- Spinal and supraspinal action
- Inhibition of sensory afferent neurons in peripheral nervous system
- Ca++ channel blockade
used as stress reducer in cats
neurokinin (NK)-1 receptor antagonists
- NK-1 receptors are diffusely distributed around body and activated by substance P
- Role in nociception is still unclear
- Role in wind-up and hyperalgesia?
- Excellent antiemetics (maropitant/cernia)
what are some antiNGF mAB meds
Anti- nerve grow factor monoclonal antibody
- cats – frunevetmab (Solensia)
- Future: Dogs – bedinvetmab (Librela®)
nutraceuticlas
omega 3 fatty acids
help ↓ OA and degenerative joint disease pain
how does cold therapy work on pain
- Decrease activation of tissue nociceptors and slow conduction velocity
- Vasoconstriction – reduce edema formation, deliver inflammatory mediators
- Decrease neuronal activity – reduce neurogenic inflammation
