Lecture 42: Opioid Cornish lecture

Question 1

What is the nation’s number one health problem?

Answer 1

Substance Abuse

• most people don’t feel like they need treatment
• no health coverage

Question 2

What is epidemiology of opioid dependence?

Answer 2

2.2 million use pain relievers NONMEDICALLY
Only 200,000 receiving treatment
-second most widely used drug after marijuana

Question 3

What are opioids?

Answer 3

Any chemical compound with pharmacologic actions similar to those of morphine
-narcotic analgesic is often referred to opioids

Question 4

What are the actions of opioids?

Answer 4

CNS: analgesia, euphoria, sedation, respiratory depression
Anti-tussive effects
Peripheral Vasodilation
Pupil CONSTRCITION
Respiratory depression
PARASYMPATHETIC

Question 5

What is Demerol?

Answer 5

An opiate pain reliever

Like Oxycontin and vicodin

Question 6

What is the MOA of opioids?

Answer 6

They act on the (mu), (kappa) and (delta) opioid receptors…all of which are coupled to Gi GPCRs
Opioids bind to GABA neurons which INHIBITS GABA and thus stimulates dopamine
Ultimate effect = increase dopamine in synapse

Question 7

What is the significance of kappa opioid receptors?

Answer 7

Expressed on dopamine neurons
Binding INHIBITS dopamine
-causes DYSPHORIC effects

Question 8

What are the most commonly abused (mu) opiods?

Answer 8

Morphine
Heroin (diacetylmorphine, rapidly metabolized to morphine)
Codeine
Oxycodone

Question 9

What is an opioid that is commonly abused by physicians?

Answer 9

Meperidine

Question 10

What is abuse?

Answer 10

Culturally disapproved use

Question 11

What is dependence?

Answer 11

Tolerance
Neuroadaptation
Repeat doses or withdrawal

Question 12

How addictive are opioids?

Answer 12

Highly addictive (on a scale of 1-5…it is a 4 so closer to highly addictive)
Addictive only when used recreationally, not when they are taken as analgesics

Question 13

How do you treat people with opioid addiction?

Answer 13

Nalaxone (acute reversal of symptoms with acute withdrawal)
Methadone and buprenorphine (long-acting opioids that are less rewarding)
-longer halflife/partial opioid agonists
-used to taper off…methadone given onece a day
-abrupt termination leads to withdrawal/dependence

Question 14

What is the significance of Methadone?

Answer 14

A long-acting opioid that is used to treat opioid addiction

-used to help taper people off from drugs like heroin

Question 15

What is Nalaxone?

Answer 15

An antagonist of opioids that reverses the effect of morphine and heroin within minutes

Question 16

What are the drugs that increase dopamine in nucleus accumbens?

Answer 16

1. Nicotine
2. Alcohol
3. Opioids
4. Cocaine

Question 17

What is a speed ball?

Answer 17

Cocaine + heroine

Question 18

Opioid drugs are classified as:

Answer 18

1. full agonists
   Example: morphine: full agonist of mu receptor
2. partial agonists
   Example: codeine: partial agonist of mu receptor
3. antagonists
   Example: Naloxone: full antagonist of mu receptor

Question 19

What are endogenous opioid peptides?

Answer 19

Peptides made in the body that bind to opioid receptors

Example: ENDORPHINS, enkephalins, dynorphines, leu-enkphalin

Question 20

hat is the difference between naloxone and naltrexone?

Answer 20

Both are opioid receptor antagonists
Naltrexone is LONGER acting (because it has longer name), so used for chronic treatment
	-given PO
	-used for ALCOHOL dependence
Naloxone used for acute
	-given IV
	-used for OPIOID dependence

Question 21

What are the withdrawal symptoms of Opioids?

Answer 21

1. Anxiety
2. Sweating
3. pupillary DILATION (because opioids constrict pupils)
4. Rhinitis
5. Diarrhea
6. Incraesed BP and respiratory rate
7. Craving

Question 22

What are the benefits of methadone?

Answer 22

-oral, long-acting and cheap
-blocking dose
-eliminates injection risks
-constant maintenance of methadone level vs. heroine which goes up an down
Methadon is like Irms while Heroine is like Imax and Imin

Question 23

What is Buprenorphine?

Answer 23

A partial mu-opioid agonist
-ceiling effect at higher doses
-does not stop withdrawal symptoms
-lower level of dependence
HIGH affinity and SLOW dissociation

Question 24

What is Naltrexone used for?

Answer 24

Relapse prevention for BOTH opioid AND alcohol
Specific antagonist of mu-receptor
-very few adverse effects
PO and non-addicting