Opioid lecture part 2

Question 1

3 Types of opioid drugs

Answer 1

1. Agonists - elicit receptor responses of opiate receptors
2. Pure Antagonists - no inherent action after binding to receptor but block any agonist activity
3. Agonist/Antagonists - drugs having mixed effects

Question 2

Morphine is what type of opioid drug?

Answer 2

Pure agonist

Question 3

Pure agonists are activated via what receptors

Answer 3

Mu and Kappa activated

Question 4

Which type of opioid drug has unlimited analgesia

Answer 4

Pure Agonist

Question 5

With continued exposure of tissues to high concentrations of opioid agonists, what happens to the potency of the drug?

Answer 5

Potency of the drug declines so that progressively higher concentrations are required to produce the same degree of analgesia

Question 6

Partial agonists are partial ? activation and weak ? antagonist?

Answer 6

Partial Mu activation

Weak Kappa antagonist

Question 7

T or F, Partial agonist have unlimited analgesia?

Answer 7

False, Good analgesia but limited effect

Question 8

T or F, Partial agonist drugs are commonly used in dentistry

Answer 8

False, not typically

Question 9

Agonist/Antagonist drugs have what receptor antagonist and what receptor agonist?

Answer 9

Mu = antagonist
Kappa = agonist

Question 10

Which type of opioid drug is used as sedative prior to surgery; supplement to surgical anesthesia

Answer 10

Agonist/Antagonist

Question 11

Pure Antagonists are what receptor antagonists

Answer 11

Mu and Kappa

Question 12

How much analgesia does Pure antagonists have?

Answer 12

No analgesia

Question 13

What drug is a good example of a pure antagonist?

Answer 13

naloxone (Narcan)

Question 14

How is naloxone used in dentistry and in general?

Answer 14

ANTIDOTE

• used in dentistry to reduce overdose of opiates (used during conscious sedation
• Used for complete or partial reversal of opioid depression (including respiratory depression)

Question 15

How are opioids absorbed?

Answer 15

Most are well-absorbed orally

• Lungs
• Nasal and oral mucosa
• Intact skin (patches)

Question 16

How are opioids excreted?

Answer 16

As metabolites in urine

Question 17

Duration of action for opioids?

Answer 17

Orally = most produce analgesia for 4-6 hours

Question 18

Metabolism of opioids?

Answer 18

Conjugation with glucuronic acid in liver

Question 19

Can opioids be passed to fetus?

Answer 19

Yes produces respiratory depression in fetus if taken by mother

Question 20

4 Desired clinical effects of opioid drugs

Answer 20

1. Potent analgesia
2. Sedation and euphoria
3. Cough suppression
4. GI effects
   - increase smooth muscle tone
   - decrease propulsion and motility
   - used for treatment of diarrhea

Question 21

ADVERSE reactions of opioid drugs

Answer 21

1. Physical addiction
2. Respiratory depression (dose-related)
3. Nausea and vomiting (emesis)
4. Constipation
5. Miosis (pinpoint pupils)
6. Urinary retention
7. CNS effects
8. Cardiovascular
9. Biliary tract constriction
10. Histamine release
11. Pregnancy and lactation
12. Physical dependency/addiction
13. Tolerance
14. Pharmacologic effect may also be an adverse reaction
15. Severity of side effects is proportional to efficacy
16. Overdose
17. Withdrawal

Question 22

Which drugs are considered FDA pregnancy category C and can cross into breast milk

Answer 22

Morphine and Codeine

Question 23

Major symptom of overdose

Answer 23

respiratory depression

Also: pinpoint pupils, coma

• Treated with antagonist = naloxone

Question 24

What are the hypersensitivity reactions to opioids

Answer 24

Most are dermatologic

If true allergy, AVOID

Question 25

Clinical indications for opioids in dentistry and medicine?

Answer 25

Dentistry - Analgesia - Sedation Medicine - Analgesia - Sedation - Cough suppression - Diarrhea

Question 26

Drugs used in dentistry are derivatives of what?

Answer 26

Morphine and Codeine are derived from opium alkaloids Heroin = synthesized morphine product

Question 27

Name pure agonist drugs

Answer 27

1. Morphine 2. Oxycodone 3. hydrocodone 4. codeine 5. dihydrocodeine 6. propoxyphene (withdrawn from US market in Nov. due to cardiac arrhythmias) 7. meperidine 8. hydromorphone 9. methadone 10. fentanyl 11. heroin

Question 28

Name the mixed agonists/antagonists drugs

Answer 28

1. pentazocine 2. butorphanol 3. nalbuphine 4. buprenorphine

Question 29

Which drug is a mixed agonist/antagonist that is equally as potent as morphine

Answer 29

Methadone (C-II) - Inhibits ascending pain pathways - Produces generalized CNS depression - Long duration of action - ** Initially used as a maintenance regimen for heroin abuse = FDA approved detoxication and maintenance programs

Question 30

How quickly can the pure antagonist effects occur when an antidote is given

Answer 30

Within 1-2 minutes; 1-4 hours duration of action

Question 31

Two examples of pure antagonists

Answer 31

1. naltrexone - antidote given orally or IM | 2. naloxone - in dental office, IV to reverse overdose of fentanyl and meperidine (sedation)

Question 32

Most widely used route of administration for morphine

Answer 32

IM - Oral morphine is poorly absorbed - Not used in dentistry - Used primarily for post-recovery pain

Question 33

Describe the morphine chemical structure

Answer 33

Piperidine ring structure = 6 sided | - Needed to bind to opiate (mu) receptor

Question 34

What is the most widely abused drug by hospital personnel?

Answer 34

meperidine (Demerol) | - Excellent analgesic, but addictive

Question 35

T or F, meperidine has No Misois.

Answer 35

True - Addicts use this drug because it masks the pinpoint pupils that they would get from abusing morphine

Question 36

Primary side effects of Demerol?

Answer 36

``` Nausea Respiratory Depression (risk for death in addicts) ```

Question 37

Is Demerol used in dentistry?

Answer 37

Yes, IV sedation (not as potent as fentanyl) - Wider margin of safety - 25 mg IV dose Orally for moderate to severe pain - 50-100 mg orally q 4 hours as needed - 3-4 hour duration of action