opioid analgesis

Question 1

What is the purpose of opioid analgesics?

They are ____ because of their potential for ____?

Answer 1

To relieve moderate to severe pain

controlled substances, abuse

Question 2

Opioid anagelsics exert their effects by binding to ____ that are located where?

Answer 2

Specific neuronal receptors located in the CNS

Question 3

What is a narcotic?

Answer 3

When taken they have sleep inducing side effects and high doses can produce a state of unresponsiveness and stupor

Question 4

What is the source of opioid analgesics?

The source of naturally occurring and semisynthetic narcotics?

Answer 4

Natural, synthetic, or semisynthetic sources

Opium poppy

Question 5

Opium contains about how many biologically active compounds?including what?

Answer 5

20 compounds including morphine and codeine

Question 6

What are the three families of endogenous opioids?

Answer 6

endorphins, enkephalins, and dynorphins

Question 7

T/F do endogenous opioids exert their effects with he same receptor as exogenous opioids?

Answer 7

True

Question 8

What are the the three receptor classes for opioid receptors?

Answer 8

Mu, Kappa, Delta

Question 9

Stimulation of all three classes of opioid receptors causes…

However, which receptors are most important in mediating the analgesic effects of morphine?

Answer 9

Analgesia

Mu

Question 10

What is the purpose of strong agonists?

Strong agonists have a high affinity for what receptor?

The most common member of this group is?

Answer 10

Strong agonists treat severe pain

Mu receptor in the CNS

Morphine

Question 11

What is the purpose if mild to moderate agonists?

Answer 11

to treat moderate pain; do not have high efficacy as strong agoniosts

Question 12

What are mixed agonist and antagonists?

How do these cause analglesia?

What are strength and weaknesses?

Answer 12

Exhbit some agonist and antagonist like activity at the same time

They bind to activate Kappa receptors and block or partially activate Mu receptors

Strengths- less risk of side effects of Mu receptors
Weaknesses- may produce psychotropic effects
- maximal analgesic effect may not be as strong as strong mu agonists

Question 13

What is the purpose of the antagonist?

How is this achieved?

What are the primary agents uses as opioid antagonists?

Answer 13

Not produce analgesia but rather treat opioid overdoses and addiction

Displaces opioid agonists from the opioid receptors and block agonist effects

• Naloxone which reverses respiratory depression
• Naltrexone treats alcohol dependence

Question 14

How can opioid analgesics be administered?

Answer 14

• oral
• parenterally, subcutaneous or intramuscular injection
• IV, epidural and intrathecal
• Transdermal patches
• Iontophoresis

Question 15

Where are opioid receptors in the spinal cord concentrated and function?

Answer 15

On neurons in the dorsal horn; inhibit synapses responsible for transmitting nociceptive input to higher levels

Question 16

Where can opioid drug (spinal effects) receptor interactions also take place?

What happens when these receptors are stimulated?

Answer 16

On the post synaptic membrane secondary afferent neuron

These receptors inhibit pain transmission by hyperpolarizing the postsynaptic neuron. making it less effective in relaying pain transmission because less NM is released

Question 17

Where do opioids in the supraspinal brain affect?

Answer 17

Opioids affect the PAG in the midbrain to remove inhibition of descending efferent pathways

Question 18

Where are opioid receptors located outside the CNS?

Answer 18

On the distal ends of primary afferent neurons

Question 19

What type of administration should be used first for opioids?

Answer 19

Oral administration of mild to moderate opioid agonist

Question 20

What is physical dependence?

Symptoms become evident within____ and peak on days ____ and _____; lasts about _____ days

Answer 20

The onset of withdrawal symptoms when the drug is abruptly removed

6-10 hrs; 2 and 3 days; lasts about 5 days

Question 21

What are some problems and adverse effects of using opioids?

Answer 21

• mental slowing and drowsiness
• respiratory depression
  -orthostatic hypotension
  -GI distress: nausea, vomiting, and constipation

Question 22

Why is Methadone of good use for those with opioid addiction?

Answer 22

Offers several advantages to patient such as milder withdrawal symptoms

Question 23

This opioid-induced hyperalgesia is likely due to _____ in nociceptive pathways in susceptible patients.

Answer 23

increased activity of glutamate