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Flashcards in Sedative Hypnotics Deck (41):
1

Define hypnotic

Drowsiness, promotes sleep, profound CNS depression

2

Define catalepsy

rigidity of the limbs, unresponsive to environmental stimuli

3

Define anxiolytic

anxiety relieving

4

Define sedative

ability to calm, reduce anxiety, mild depression of cerebral cortex

5

Define tranquilizer

neuroleptic, anxiety reduced w/ no loss of consciousness; hypothalamus and reticular formation fx depression

6

What is the difference in the mech of action between benzodiazepine and barbiturates?

BZ- binds GABA-a, Cl- influx, membrane hyperpolarization, decreased firing, ONLY in PRESENCE OF GABA

Barb- prolongs the duration of Cl- channels opening; inhibits NE, Ach and Glutamate. Does not req GABA

BOTH result in GABAnergic neurotransmission

7

What are the therapeutic effects of benzodiazepines?

anxiolytic, muscle relaxant, sedative-hypnotic

8

What are the pharmalogical effects of benzodiazepines?

dose dependent CNS depression, effects only in presence of GABA

low dose- sedative; high- hypnosis/anesthesia

anterograde amnesia; anti-convulsant

9

How does benzodiazepine cause muscle relaxation?

potentiation of GABAnergic neurotransmission in the spinal cord

10

What effects does BZ have on cardio, resp tract and uterus?

Cardio- collapse at toxic dose, but not significant in healthy animals

resp tract- PR and Tidal Volume minimally affected

uterine- crosses placenta, TERATOGENIC

11

T/F

Benzodiazepines do not induce CYP-40

TRUE

Barbiturates do

12

What are the 3 benzodiazepine agonists?

Diazepam

Midazolam

Zolazepam

13

Diazepam

long T1/2
crosses BBB
relaxant, tranquilizer, anticonvulsant
minimal effect on cardio/resp
Neuroleptanalgesia
hapatoxic in cats

14

Midazolam

older animals neuroleptanalgesic
more potent than diazepam
water soluble at low pH
IM/IV

15

Zolazepam

telazol- uscle relaxation, exclusively used w/ tiletamine
induction agent

16

What is teh only BZ antagonist?

Flumazenil

17

Flumazenil

only reveral agent
competitive antagonist of GABA receptor
Counteract resp depression associated with IV diazepam
ONLY GIVE IV
must give repetitive doeses, can lead to toxicity
may cause seizures, arrhythmia , dizziness

18

What are barbiturates used for?

anesthesia and seizure management

19

Barbiturate activity largely depends on _____

lipid solubility

20

Whataare the main 3 barbiturates, their duration of action and major clinical use?

Phenobarbital- long acting; seizures

Pentobarbital- short acting, induction, euthaniasia

Thiopental- ultra short; induction, neurosurgical procedures

21

What are the 2 major classes of sedative hypnotics?

Phenothiazine derivatives; major tranquilizers

Butyrophenone derivitives

22

What are the major pharm effects of phenothiazines?

sedation, antiemetic, anti- arrhythmia, anti histaminergic, hypotensice effect, hypothermic effect

23

What are the 2 major phenothiazines?

chlorpromazine

acepromazine

24

What are the 2 major butyrophenones?

droperidol

azaperone

25

Droperidol

used for surgical neuroleptanalgesia in SA sx

psychomotor depression

26

Azaperone

FDA approval for swine
sedative and premedicant
controls aggressive behavior
sedation in pigs prior to transport

27

What is the mech of action of phenothiazines?

blockade of post synaptic mesolimbic dopaminergic receptors (D2)

blockade of alpha-1 adrenergic receptors, H1 histaminergic receptors, and serotonin receptors

28

What is the site of action of phenothiazines?

basal ganglia, limbic system, thalamus, brain stem, hypothalamus, reticular activating system

29

What effect do phenothiazines have on the CNS?

sedation

depression of brain stem and pathways linking to cerebral cortex

diminished arousal motility, decreased motor activity

extrapyramidal symptoms

anitemetic activity in dogs but not cats

30

What are extrapyramidal effects?

rigidity, tremors, akinesia

31

What cardiovascualr effects of phenothiazines

blocks alpha-1 receptor activation in peripheral vascualture- Net result is vasodilation

32

what is reflex tachycardia?

phenothiazines block alpha-1 receptors, cause peripheral vasodialtion, interpreted by baroreceptors as hypotension, tachycardia develops as result

33

What are the respiratort effects of phenothiazines

minimal effects

34

What are the dermatological effects of phenothiazines

promethazine and trimeprazine block H1

35

T/F phenothiazines produce profound analgesic effects

FALSE

they dont do this

36

How do phenothiazines cause hypothermia?

depress thermoregualtion of the hypothalamus;

increased heat loss via vasodialtion

decrease heat pdx via decreased muscle activity

37

What are butyrophenones used for?

sedative and pre-anesthetic agent

same mech of action as phenothiazines

38

What CNS effects to butyrophenones have?

potent antiemetic effects
controls drug induced vomiting

39

What are the cardiopulmonay effects of butyrophenones?

mild hypotension due to blockade of peripheral alpha-1 receptors

minimal effects on CO/resp depression compared to phenothiazines

40

Adverse effects associated w/ phenothiazines:

accidental intracarotid administration in the horse leads to seizure/death

mimic/similar to clinical signs of organophosphate poisoning - Cholinesterase inhibitor

lower seizure threshold

NO REVERSAL AGENT

Contraindicated in hypovolemic administration

41

Therapeutic uses of phenothiazines/butyrophenones

tranquilizers
pre-anesthetic in general anesthesia, allows dose reduction and amelioration of adverse effects associated w/ some anesthetic agents
antiemetics