Premedication Flashcards
1
Q
why use premedication?
A
- humane-minimizes stress
- may decrease requirement
- injectables
- inhalants
- synergism
2
Q
neuroleptic
A
major sedatives
(early described antipsychotics)
3
Q
analgesics
A
opioids
4
Q
neuroleptoanalgesia
A
sedative + opioids
5
Q
drug selection based on
A
- species
- age
- physcial status (ASA)
- animal behavior and attitude
- procedure
- duration of procedure
- experience with drugs used!!!
6
Q
anticholinergics
A
-
desired effect: anti-muscarinic effect at the post synaptic receptors
- increase HR, treat bradycardia
-
undesired effect: anti-muscarinic effect at the presynaptic feedback receptor
- worsening of bradycardia initially
- atropine sulfate
- glycopyrrolate
7
Q
effects of anticholinergics
A
- decrease vagal influence in HR
- decrease secretions
- bronchial dilation
- increase anatomical and physiologic dead space
- decrease GI motor and secretory activity
8
Q
atropine sulfate
A
- anticholinergic
- tertiary amine molecule
-
high lipid solubility
- easily crosses BBB and placental barrier
- fast acting
9
Q
glycopyrrolate
A
- anticholinergic
- synthetic quaternary ammonium molecule
-
low lipid solubility
- doesn’t cross BBB and placenta
- no effects on CNS
- same peripheral effects of atropine
- lasts longer than atropine (1.5-2 hours)
10
Q
tranquilizers
A
- major tranquilizers
-
phenothiazines
- acepromazine
- buyrophenones
- Droperidol
- Azaperone
-
phenothiazines
11
Q
acepromazine maleate
A
- potent sedative and anxiolytic
- anti-emetic
- anti-arrhythmic properties
- decreased dose requirement of other drugs
- enhances analgesia of opioids
- Boxer (very sensitive)
- not reversible!
12
Q
side effects of Ace
A
- decreased BP and vasomotor reflex (alpha antagonist)
- cardiac depression
- peripheral alpha2-adrenergic blockade
- relaxation of vascular smooth muscle
- persistent or permanent penile paralysis (horses)
13
Q
opioids
A
- mu-agonists
- morphine
- fentanyl
- partial agonists
- buprenorphine
- buprenorphine SR
- k-agonist/mu-antagonists
- butorphanol
- antagonists
- naloxone
- naltrexone
14
Q
mu-agonists
A
- greater analgesic potential
-
duration and side effects used to decide which drug to use
- respiratory depression
- vomiting
- bradycardia
- decrease GI motility
15
Q
morphine
A
- mu agonist
- prototype
- potency = 1
- long duration (4-6 hours)
-
histamine release
- IV-administer carefully
- hypotension
- urticaria
16
Q
hydromorphone
A
- mu agonist
- potency = 10
- long duration (4-6 hours)
- feline hyperthermia?
17
Q
methadone
A
- mu agonist
- potency = 1.5
- long duration (4-6 hours)
- NMDA- antagonist
18
Q
fentanyl
A
- mu agonist
- potency = 100
-
short duration (20-30 min)
- most used as CRI
19
Q
buprenorphine
A
- partial mu-agnoist
-
long onset of action
- 30 min IV, 45-1 hr IM
- long duration (6-12 hours)
- bind strongly to receptor
- reversible but takes more naloxone
- cats: good oral bioavailability, over 85%
- dogs: poor oral bioavailability, 39%
20
Q
butorphanol
A
- k agonist/mu antagonist
- good sedative
- mild to moderate analgesia
- can be used to reverse side effects of mu-agonists
-
very short acting
- good for minor procedures
21
Q
nalbuphine
A
- k agonist/mu antagonists
- very similar to butorphanol
- not controlled
- comes in ampules
- not used commonly
22
Q
benzodiazepines
A
- diazepam
-
midazolam
- anterograde amnesia
- GABA
23
Q
diazepam
A
- benzodiazepine
- anxiolytic
- muscle relaxant
- anticonvulsant effect
- rapidly crosses BBB and placental barrier
- minimal CV effects (decrease BP and CO)
- propylene glycol (high lipid solubility)-IV
- inhibit inhibitory neurons before excitatory-spaz out = bolus!
24
Q
midazolam
A
-
water soluble (become lipid soluble pH > 4)
- closing of imidazole ring
- can be given IM
- more potent but shorter acting than diazepam
- similar effects to those of diazepam
- crosses BBB and placental barrier
25
Q
zolazepam
A
- most potent benzo used in vetmed
- available only in telazol
- 1:1 ratio
- anticonvulsant and muscle relaxant
- the least apt to cause CNS depression
26
Q
flumazenil
A
- competitive antagonist of benzodiazepine receptor = reversal agent
- very weak agonist effect (no anxiety with reversal)
27
Q
alpha2-adrenergic agonists
A
- anxiolytic, sedative and muscle relaxant
- analgesia
- decrease ADH release
- decrease insulin release (hyperglycemic)
- hypertension follow by hypotension
- reflex bradycardia
28
Q
CV effects of alpha2-agonists
A
-
decrease HR
- hypertension
- decrease sympathetic tone
-
decrease CO
- decrease myocardial contractility
- decrease HR
- increase then decrease BP
29
Q
xylazine
A
- alpha 2-agonists
- less selective to alpha 2
- more ataxia
- shorter duration
30
Q
detomidine
A
- alpha 2-agonist (LA)
- still not very selective
- profound sedation
- ataxia
31
Q
romifidine
A
- alpha 2 agonist (LA)
- still not very selective
- good sedation
- less ataxia
32
Q
dexmedetomidine
A
- alpha 2 agonist (SA)
- most selective
- profound sedation
- may intubate some dogs
- vasoconstriction
- fast IM
33
Q
reversals
A
-
non-selective
- tolazoline
- yohimbine
- only SC or IM
-
alpha 2 selective
- atipamizole (dexmedetomidine)
- only SC or IM
34
Q
guaifenesin
A
- central muscle relaxant (different from NMB!)
- used as adjuvant in large animal induction
- it smoothes induction and decreases injectable dose
- it disrupts transmission at spinal cord and brain stem
- increase RR and decrease tidal volume (min vent unchanged)
35
Q
ketamine + alfaxalone =
A
premed to cause chemical restraint
higher doses than IV
used in difficult patients
