Opiods

List the five common opiods used in vet med?

• Butorphanol (Torbugesic)

• Buprenorphine (Buprenex)

• Morphine

• Fentanyl

• Methadone

Why do we use opiods? (3

• Very safe, reversable

• Provide significant levels of analgesia

• Reduction of anxiety and nonpainful responses to distress

What two receptors do opiods mainly bind to? What level of analgesia do they provide?

Mu (significant analgesia)

Kappa (milder analgesia)

How do opiods work?

They block the pain pathway at noiciceptors, spinal cord, and brain

What are clinical signs an opiod has been used?

• Respiratory depression

• Euphoria (relaxed)

• Sedation

• Miosis

What does a pure agonist opiod do?

Bind to all receptors and cause the maximum analgesia

What are examples of pure agonist opiods? (2)

Morphine and Hydromorphone

What is the duration of pure agonists?

Medium (four hours)

What are some side effects of pure agonists?

• Sedation

• Low Blood Pressure

• Respiratory Depression

• Hypothermia (Dogs)

• Hyperthermia (Cats)

What is an example of a partial agonist opiod?

Buprenorphine

What receptor does a partial agonist bind to?

Mu

What is the duration of partial agonists?

8-12 hours

What is an example of an agonist-antagonist?

Butorphanol

What receptor does Butorphanol bind to? Which one does it antagonize?

Binds to kappa, antagonizes mu

When would you use Butorphanol? Why?

CV distress or collapsing trachea to take the edge off since it provides some analgesia and sedation

What is an example of an antagonist?

Naloxone