1. Chapter 9: Opioid Analgesics
Presented by:
Steffani and Katie

2. Location of opioid receptors in the brain and in the brain stem:
Thalamus
Brain Stem
Limbic System

3. How are pain impulses modulated as they enter the spinal cord?
The pain impulses can be modulated by one of 2 pathways by activating pain-inhibitory systems. Both systems activate norepinephrine and serotonin – releasing neurons in the spinal cord which inhibits the release of transmitters for pain neurons.

4. Substance P:
A neuropeptide (amino-acid chain) that is a pain-signaling neurotransmitter.
It is influenced by narcotic analgesics by inhibiting the release of Substance P presynaptically.

5. Effects of Endorphins:
To inhibit the release of transmitters from primary afferent (nociceptive) pain neurons.

6. What is?
Opioid Agonist: Drug that has an affinity for cell receptors to induce changes in the cell characteristics of the natural ligand for that receptor. Example: Morphine
Opioid Antagonist: Drug that has an affinity for the receptor but, once attached, has no effect other than to BLOCK the receptor from the drugs that DO cause an effect. Example: Naloxone

7. What is?
Mixed Agonist-antagonist: Drug that produces an agonist effect at one receptor and an antagonist effect at another receptor. These are useful in treating opioid dependency because they limit withdrawal symptoms to some degree.
Example: Nubain
Partial Agonist: Drug that binds to opioid receptors but has a low intrinsic activity (low efficacy). Example: Ultram

8. Why Misuse or Abuse Opioids?
Addiction is reinforced by the positive physical feelings (euphoric state, strong feeling of well-being and contentment, and lack of concern).
Provides user with an experience that the brain equates with profoundly important events like eating, drinking and sex.
Becomes an acquired drive state that permeates all aspects of human life. (See page 271)

9. Naloxone and Naltrexone
Both are pure opioid antagonists.
However, naloxone is the prototype antagonist. It must be given intravenously and has a brief duration of effectiveness (needs to be re-injected at short intervals).
Naltrexone is different in that it is orally administered and has a longer duration of effectiveness.
Naltrexone is indicated for use in the treatment of alcohol abuse.

10. Handling and Treating Opioid Dependency:
RAAD: Rapid, Anesthesia-aided Detoxification: Administering an opioid antagonist while patient is under general anesthesia. This procedure cycles at which time the withdrawal symptoms are blunted (the idea is to detoxify a patient while unconscious).
2. Use naltrexone, methadone or LAAM (levo-alpha acetylmethadol) to reduce opioid cravings paired with supportive psychotherapy to address underling causes of addiction and prevent relapse. Also, psychotherapy is needed to treat comorbid psychological disorders.

11. Thoughts for and against the existence of endogenous opioid peptides (endorphins) that serve as natural opioids.
We believe they exist as natural analgesics that dampen pain and influence emotions.
Katie personally experienced this effect during distance running and childbirth.

12. Buprenorphine:
A semisynthetic, partial agonist opioid with long lasting analgesic properties.
It has a potential use as a substitute for methadone or a step down drug from methadone for the detoxification and maintenance of opioid users.

13. Options in the pharmacological management of opioid withdrawal and the prevention of relapse: Data support lifelong opioid maintenance as a treatment option since the rate-of return to illicit opioid use is significant despite treatment interventions.