Analgesics

Question 1

pain pathways

Answer 1

opioids - at level of brain and spinal cord
alpha 2s - at level of brain and spinal cord
LAs - spinal cord, peripheral nerves or peripheral nociceptors
anti inflammatory drugs - peripheral nociceptors

Question 2

opioids

Answer 2

receptors - mu delta, kappa, nociceptin

side effects -
CVS
pruritis
urinary retention
ileus
temperature
miosis and mydriasis
vomiting and nausea
respiratory depression

Question 3

morphine

Answer 3

full agonist
mu, delta, kappa

not licensed

Question 4

methadone

Answer 4

full agonist
mu

Question 5

pethidine

Answer 5

full agonist
mu

increased HR
not IV - causes histamine release

used in horses for spasmodic colic

Question 6

fentanyl

Answer 6

full agonist
mu

short acting

slowed respiration and hr

Question 7

buprenorphine

Answer 7

partial agonist
mu

moderate pain relief, sedation

Question 8

butorphanol

Answer 8

kappa agonist
mu antagonist - so can’t use a mu agonist after, wont work well

used in combination with ACP for sedation

limited analgesia

Question 9

local anaesthetics

Answer 9

block sodium channel function

ionise at physiological pH - take longer to work in inflamed tissue

Question 10

lidocaine

Answer 10

effect ranges depending on amount given -
anticonvulsant
antiarrythmia
muscular twitching
unconsciousness
CNA depression - at highest dose

Question 11

NSAIDs

Answer 11

COX inhibitors - inhibit prostaglandin production, synergistic with other drugs

GI side effects

Galliprant - piprant NSAIDs - non-COX inhibiting, used for osteoarthritis - may be used when traditional NSAIDs not tolerated BUT NOT IN CATS

contraindications -
liver or kidney disease
hypovolemia
congestive heart failure
spinal injuries
gastric ulceration
steroids
shock
trauma
pregnancy

Question 12

paracetamol

Answer 12

don’t use in cats
don’t know how it works

Question 13

alpha 2 adrenorecptor agonists

Answer 13

medetomidine, dexmedetomidine, xylazine, romifidine

sedative, analgesia and reduced MAC

side effects -
hyper then hyptension
decreased HR and CO
respiratory depression
increased urinary production
decreased GI motility
hyperglycemia
vasoconstriction

pre med, sedation, PIVA/TIVA. epidural, rescue analgesia

antagonised by atipamazole

Question 14

NMDA antagonist

Answer 14

ketamine

induction and peri operative analgesia
improves post op comfort
muscle rigidity - must be used in combination with other drugs for relaxing