Opioid Analgesics 2

Question 1

What opioid receptor will give you spinal analgesia, miosis (pinpoint pupils) and sedation?

Answer 1

Kappa

Question 2

What opioid receptors give you analgesia, emotion and seizures?

Answer 2

Delta

Question 3

What opioid receptors give you dyphoria, hallucinations, nightmares, anxiety?

Answer 3

Sigma

Question 4

What opioid receptor gives you just analgesia?

Answer 4

Epsilon

Question 5

The strength of attachment of an opioid drug to its binding site is proportional to what?

Answer 5

It’s potency

The stronger the affinity - the higher the potency

Question 6

Opioids act by?

Answer 6

• Presynaptic inhibition of production of neurotransmitters C-fiber endings
• Postsynaptic suppression of evoked activity in nociceptive path or remove the remaining parts of the regulation of inhibition of nociceptive impulses
• Increased transmission of the descending inhibition of spinal nociceptive conduction

Question 7

What do opioids cause (3 things)?

Answer 7

1. Hyperpolarization of nerve cells
2. Inhibition of nerve firing
3. Presynaptic inhibition of transmitter release

Question 8

What are the examples of opioids?

Answer 8

• Endogenous opioid peptides
• Opium alkaloids (poppy plants - morphine and codeine)
• Semi-synthetic opioids
• Fully synthetic opioids

Question 9

What’s a pure agonist, and what is the prime example of a pure agonist?

Answer 9

Complete receptor activation - mu and kappa activated

Unlimited analgesia - MORPHINE

Question 10

What’s a major problem with opioids?

Answer 10

Tolerance - the potency of the drug declines so that progessively higher concentrations are required to produce the same degree of analgesia -

Question 11

What are the characteristics of a partial agonist and give an example?

Answer 11

Example: buprenorphine (Buprenex)

Parital mu activation, good analgesia but limited effect

Question 12

If one become tolerant to one opioid what is a possibility with other opioids?

Answer 12

They can become cross-tolerant to other opioids

Question 13

What is an example of agonist/antagonist?

Answer 13

Example: pentazocine (Talwin)

• Mu - anatagonist
• Kappa - agonist (sedative prior to sugery, supplement to surgical anesthesia)

Question 14

What is an example of a pure antagonist, and what are the characteristics?

Answer 14

Example: naloxone (Narcan)

No analgesia

Question 15

What is used for an antidote of overdosed opioids?

Answer 15

naloxone (Narcan)

Pure antagonist - used for complete or partial reversal of opioid depression

Question 16

Where are opioids absorbed?

Answer 16

Most are well-absorbed orally

Lungs, nasal and oral mucosa, and intact skin all good places as well

Question 17

What’s the distribution of opioids?

Answer 17

First pass effect reduces bioavailability, can pass to fetus

Question 18

***What are the desired clinical effects of opioid drugs?

Answer 18

• Potent analgesia
• Sedation and euphoria
• Cough suppression
• GI effects
  
  • increase smooth muscle tone
  • decrease propulsion and motility
  • used for treatment of diarrhea

Question 19

What’s the number one compliant of people who take opiates?

Answer 19

Constipation

Question 20

All opiates have the same adverse reactions, what are the?

Answer 20

• Physical addiction
• Respiratory depression
• Nausea and vomiting
• Constipation
• Miosis (pinpoint pupils)
• Urinary retention
• CNS effects - stimulatory effects, anxious
• Cardiovascular - bradycardia (depressent)
• Biliary tract constriction
• Histamine release - itching and urticaria

Question 21

Why don’t we use opioids in pregnancy?

Answer 21

Prolongs labor, depresses fetal respiration if given near term, infants born addicted

Question 22

The severity of the side effects of opiates are proportional to its _________?

Answer 22

Efficacy

Question 23

What are signs of opioid overdose?

Answer 23

• Respiratory depression
• Pinpoint pupils
• Coma

Treat with anatagonist - naloxone

Question 24

What are signs of opioid withdrawal?

Answer 24

• Yawning, lacrimatoin, perspiration, piloerection, irritability, tachycardia, tremors, etc

Question 25

What are most of the hypersensitivity reactions to opioids?

Answer 25

Most are dermatologic - skin rashes, urticaria

If true allergy - avoid

Question 26

What are the clinical indications for opioids?

Answer 26

• In dentistry:
  
  • Analgesia, sedation
• In medicine:
  
  • Analgesia, sedation, cough suppression, diarrhea

Question 27

How do you obtain opium?

Answer 27

Dried juice obtained from unripe seed capsules of poppy plant (25% of dried juice consists of the alkaloids: morphine, codeine, papaverine)

Question 28

What are the drugs used in dentistry that are derivatives from opium alkaloids?

Answer 28

Morphine, Codeine

Question 29

What is Heroin?

Answer 29

Synthesized morphine product (diacetyl morphine)

Question 30

What are the pure agonists?

Answer 30

• oxycodone (Percodan, Percocet)
• hydrocodone (Vicodin, Lorcet)
• codeine
• dihydrocodeine (Synalgos D-C)
• propoxyphene (Darvon)
• meperidine (Demerol)
• fentanyl

Question 31

What pure agonist opioid was withdrawn from US marked in November 2010 due to cardiac arrhythmias?

Answer 31

propoxyphene (Darvon)

Question 32

What is the mixed agonist/antagonist opiate?

Answer 32

Methadone (C-II)

Question 33

What are some characteristics of Methadone?

Answer 33

• Equally as potent as morphine
• Initially used as a maintenance regimen for heroin abuse - FDA approved detox programs

Question 34

What drug was initially used as a maintenance regimen for heroin abuse?

Answer 34

Methadone

Question 35

Why are pure antagonist opioid drugs kept in dental offices that administer sedation?

Answer 35

To reverse effects of narcotics/overdose

Question 36

What are the opiate antidotes that can be given for sedation overdose?

Answer 36

• naltrexone (Depade, ReVia, Vivitrol)
• naloxone (Narcan)