Sedatives, Tranquilizers (L&J Chp 10)

Question 1

Advantages of sedatives, tranqs

Answer 1

• Calming patient
• Facilitating IVC placement
• Analgesia
• Reduced sympathetic responses to surgical stimulation
• Reduced anesthetic requirements
• Promoting smooth induction, recovery

Question 2

Considerations when selecting drugs

Answer 2

• Patient temperament
• Age
• Pathologic processes
• Blood volume status
• Procedure
• Etc

Question 3

Tranquilizer

Answer 3

Induces a feeling of calm (anxiolysis)

Question 4

Sedative

Answer 4

Reduce anxiety but also reduce overall response to external stimuli
+/- analgesia

Question 5

T/F: distinction btw tranq and sedative is often nebulous de to species and dosing differences so terms allowed to be used somewhat interchangeably

Answer 5

True

• Different species can vary widely in response to class of medication
• Individuals within a species may also display varying effects of a medication

Question 6

Classes of sedatives used in veterinary medicine

Answer 6

• Phenothiazines
• Benzodiazepines
• alpha2s
• Butyrophenones
• Opioids

Question 7

Phenothiazine Use

Answer 7

• Sedatives alone

- In combinations as premedication prior to anesthesia

Question 8

Phenothiazine Use - Humans

Answer 8

• Antipsychotic, antiemetic effects

- At clinically relevant doses, inhibit conditioned avoidance behaviors with reduction in spontaneous motor activity

Question 9

Extrapyramidal SE of phenothiazines

Answer 9

• Seen with long-term use in people, overdose in veterinary patients
• Tremor, coma/catalepsy, rigidity

Question 10

Phenothiazine Receptor Site Activity

Answer 10

• Adrengeric
• Muscarinic
• Dopaminergic
• Serotonergic
• Histaminergic

Question 11

Sedative effect of phenothiazine MOA

Answer 11

• Mediated primarily by blockade of dopamine (D2) R
• Pre/post synaptic GPCR blockade –> decrease cAMP/AC activity, Ca conductance and alterations in postsynaptic K+ conductance
• +/- blockade of a1, muscarinic and histaminergic R

Question 12

Effect on BP of phenothiazines MOA

Answer 12

• a1 R antagonism mediates decrease in BP

- May play role in decrease in thermoregulatory control (tendency toward poikilothermia) along with serotonin blockade

Question 13

Acepromazine

Answer 13

• One of most widely used sedatives in vetmed
• LA, SA
• Generally reliable as a sedative when given parentally, often at doses lower than label dose

Question 14

Hallmark of Acepromazine sedation

Answer 14

Muscle relaxation

Question 15

What are the two main adverse effects of acepromaziene use?

Answer 15

• decreased systemic vascular resistance

- decreased BP

Question 16

Does Acepromazine have analgesic properties?

Answer 16

NO!

Question 17

Acepromazine in practice

Answer 17

frequently given in combination with opioids to produce neuroleptanalgesia, state characterized by analgesia and sedation