Sedatives and Tranquilizers (Garcia)

Question 1

Major Tranquilizers:

Phenothiazines

Butyrophenones

Answer 1

Phenothiazines

• Acepromazine
• Chlorpromazine
• Levomepromazine

Butyrophenones

• Droperidol
• Azaperone

Question 2

Minor Tranzuilizers:

Benzodiazepines

Answer 2

Benzodiazepines

• Diazepam
• Midazolam
• Zolazepam (Telazol)

Question 3

Phenotiazines

Action

Answer 3

Dopaminergic reeptor antagonist (CNS)

• Sedation and tranquilization

Alpha receptor antagonist

• Peripheral vasodilation

Question 4

Acepromazine maleate

about

Answer 4

Potent sedative and anxiolytic

Anti-emetic

Anti-arrhythmogenic properties

Dec dose req of other drugs

Enhances analgesia of opioids

Question 5

Acepromazine

Side effects

Answer 5

Myocardial contractility depression

Relaxation of vascular smooth muscle

• dec BP and vasomotor reflex
• dec afterload: think about ben for mitral valve regurge

Peresistent or permanent penile paralysis (horse)

• rare
• alpha 2s are better

Affects platelet aggregation

Question 6

Boxers

Answer 6

Can be more sensitive to ace

Question 7

Contraindications for ace

Answer 7

Hypotension/hypovolemia

Decreased myocardial contractility

• DCM

Coagulopathies

Liver, renal dz?

Seizures?

Question 8

Droperidol and Azaperone

Answer 8

Similar to ace

Better in pigs than ace

Question 9

Benzodiazepines

Effects

Answer 9

Act on GABA

• Chlorine into cell = hyperpolarization of postsynaptic cell membrane

Sedation

Anxiolysis

Muscle relaxation

Anti-convulsive

Anterograde amnesia

Potentially can dec induction agent requirements

Question 10

Diazepam

Answer 10

Rapidly crosses BBB and placental barrier

Minimal cardiovascular effects

Propylene glycol and ethanol

• painful, NO IM INJECTIONS
• Only mix with ketamine, precipitates opioids

Viscous

Light sensitive, binds to plastic

Question 11

Diazepam

Metabolism

Answer 11

Hepatic metabolism

• Oxidative pathway

Two active metabolites

• Nordiazepam and oxazepam
  
  • NOT IN HORSES

Question 12

Midazolam

Answer 12

Water soluble (lipid soluble at pH > 4)

• Mixes well with other drugs
• Closing of imidazole ring

Can be given IM

More potent/shorter acting than Diazepam

Crosses BBB and placenta

Question 13

Zolazepam

Answer 13

Most potent benzo in vet med

Only avail in Telazol

Anticonvulsant and muscle relaxant

Question 14

Reversal and acepromazine

Answer 14

There is none

Question 15

Flumazenil

Answer 15

Reversal of benzos

No anxiety with reversal

Question 16

Alpha2-adrenergic Agonists

Answer 16

Throughout whole body

Acts on pre-synaptic alpha-2 receptor on sympathetic system

• Decrease in NE release
  
  • sedation
  • muscle relaxation
  • vasodilation
  • pre-synaptic bradycardia

Question 17

Alpha-2 adrenergic agonists post-synaptically

Answer 17

Mimics NE and EPI

• Vasoconstriction
• Post-synaptic bradycardia

Question 18

Action of Alpha-2 adrenergic Agonists

Answer 18

Anxiolytic

Sedative and muscle relaxant

Analgesia

Dec ADH release

Dec insulin release

Hypertension followed by hypotension

Reflex bradycardia

• causes AV block in small animals

Question 19

Cardiovascular effects of Alpha-2s

Answer 19

Dec HR

• hypertension
• dec sympathetic tone

Dec CO

• Dec myocardial contractility
• Dec HR

Then inc something and dec BP

Question 20

Xylazine

Answer 20

Dirty drug

Less selective to alpha-2 receptors

More ataxia

Shorter duration

Question 21

Detomidine

Answer 21

Still not very selective

Profound sedation

Ataxia

Question 22

Romifidine

Answer 22

Not very selective

Good sedation

Less ataxia

• good for wobbler horses

Question 23

Dexmedetomidine

Answer 23

Dec cardiac output

Most selective

Profound sedation

May indubate some dogs

Atropine contraindicated

Question 24

Reversals

Non-selective

Alpha 2 selective

Answer 24

Non-selective: SC or IM only

• Tolazoline
• Yohimbine

Alpha 2 selective: SC or IM only

• Atipamizole

These may be given IV in large animals