Opioids.Non.Opiods.Notes

Question 1

What is the Greek origin of the word narcotic?

Answer 1

Derived from Greek word ‘norkoikos’ meaning stupor

Term used to describe potent morphine-like analgesics with potential to produce physical dependence.

Question 2

Define opioid.

Answer 2

Drugs derived from either natural or synthetic means that bind to any opioid receptors

Potent morphine-like analgesics with potential to produce stupor, insensibility, and dependence.

Question 3

What is an opiate?

Answer 3

Drugs derived from opium

This term specifically refers to natural substances obtained from the opium poppy.

Question 4

Name the four types of opioid receptors.

Answer 4

• Mu (μ) receptor
• Delta (δ) receptor
• Kappa (κ) receptor
• Nociceptin (NOP) receptor

Each receptor type has distinct roles and effects in the body.

Question 5

What are the general characteristics of opioid receptors?

Answer 5

• Protein receptors on nerve cells
• Respond to opioids (endogenous and exogenous)
• Major roles: Pain control, Mood, Stress, Reward

These characteristics define how opioids interact with the nervous system.

Question 6

How do opioid receptors work?

Answer 6

When an opioid binds:
* ↓ Adenylate cyclase → ↓ cAMP
* ↓ Calcium influx → ↓ neurotransmitter release
* ↑ Potassium efflux → neuron hyperpolarization

Neurons fire less, leading to suppressed pain signals.

Question 7

Where are opioid receptors located?

Answer 7

• Brain (pain, reward, breathing centers)
• Spinal cord (pain transmission)
• Peripheral nerves

Specific areas include the periaqueductal gray, locus coeruleus, and dorsal horn.

Question 8

What is the effect of opioids on ascending pain pathways?

Answer 8

Inhibit pain transmission in spinal cord and brainstem

This prevents pain signals from reaching higher brain centers.

Question 9

What do opioids do to descending inhibitory pathways?

Answer 9

Stimulate descending pain control pathways

This enhances the body’s natural pain inhibition mechanisms.

Question 10

What neurotransmitters do opioids reduce the release of?

Answer 10

• Substance P
• Glutamate
• Other excitatory neurotransmitters

This dampens central sensitization of pain.

Question 11

What are the effects of the Mu1 receptor subtype?

Answer 11

• Analgesia (supraspinal & spinal)
• Bradycardia
• Euphoria
• Low abuse potential
• Miosis
• Hypothermia
• Urinary retention

This receptor subtype is primarily responsible for pain relief.

Question 12

What are the effects of the Mu2 receptor subtype?

Answer 12

• Analgesia (spinal only)
• Bradycardia
• Respiratory depression
• Constipation
• Physical dependence

This subtype is associated with more severe side effects.

Question 13

What is the role of the Delta (δ) opioid receptor?

Answer 13

• Modulates analgesia
• Influences mood and emotional response to pain
• Plays role in tolerance and opioid adaptation

It is not the primary target for strong clinical analgesia.

Question 14

What are the effects associated with the Kappa (κ) opioid receptor?

Answer 14

• Produces spinal-level analgesia
• Less respiratory depression than μ
• Associated with dysphoria and sedation

Kappa agonists can cause unpleasant mood changes.

Question 15

What are endogenous ligands?

Answer 15

Body’s own ‘natural opioids’ that bind to opioid receptors

Examples include endorphins released during intense exercise or stress.

Question 16

What is the classification of opioids by receptor activity?

Answer 16

• Agonists
• Partial Agonists
• Antagonists
• Mixed Agonist-Antagonists

Each category has distinct effects and uses in pain management.

Question 17

What are naturally occurring opioids?

Answer 17

Derived directly from opium poppy

Examples include Morphine and Codeine.

Question 18

What are semisynthetic opioids?

Answer 18

Chemically modified from naturally occurring opiates

Examples include Hydromorphone and Oxycodone.

Question 19

What are synthetic opioids?

Answer 19

Completely man-made compounds not directly derived from poppy

Examples include Fentanyl and Methadone.

Question 20

What is the classic triad of opioid overdose?

Answer 20

Miosis + Hypoventilation + Coma

This triad suggests opioid overdose.

Question 21

What is the treatment for opioid overdose?

Answer 21

• Mechanical ventilation
• Opioid antagonist administration (Naloxone)

Naloxone promptly reverses opioid-induced analgesia and respiratory depression.

Question 22

What is the definition of withdrawal?

Answer 22

Physiological response to abrupt cessation or rapid reduction of opioid use

Early signs include diaphoresis and insomnia.

Question 23

What are early signs/symptoms of withdrawal?

Answer 23

• Diaphoresis
• Insomnia
• Restlessness

These symptoms indicate the body’s response to the absence of opioids.

Question 24

What are the later signs/symptoms of withdrawal?

Answer 24

• Abdominal cramping
• Nausea and vomiting

These symptoms occur as withdrawal progresses.

Question 25

What is the **mechanism of withdrawal**?

Answer 25

Abrupt withdrawal leads to increase in sympathetic nervous system activity ## Footnote This results in various withdrawal symptoms.

Question 26

What are the **system-specific effects** of opioids on the cardiovascular system?

Answer 26

* Relatively hemodynamically stable * Bradycardia from medullary vagal stimulation * Dose-dependent vasodilation ## Footnote Histamine release can cause hypotension, especially with Morphine and Meperidine.

Question 27

What are the **effects of opioids on the respiratory system**?

Answer 27

* Cough suppressant * Depress respiratory centers * Risk of hypercapnia and hypoxia ## Footnote Onset of apnea occurs before unconsciousness.

Question 28

What are the **gastrointestinal effects** of opioids?

Answer 28

* Constipation * Biliary colic * Delayed gastric emptying ## Footnote Opioids cause spasms of GI smooth muscles.

Question 29

What is **serotonin syndrome**?

Answer 29

Potentially life-threatening drug reaction with excessive serotonin levels ## Footnote Symptoms include autonomic instability, hyperthermia, and neuromuscular abnormalities.

Question 30

What is the **definition of addiction**?

Answer 30

A disease where a person cannot stop using a drug despite negative consequences ## Footnote This is also referred to as substance use disorder.

Question 31

What are the **fetal effects of opioids** during pregnancy?

Answer 31

* Ventilatory depression * Physical dependence in neonate ## Footnote This occurs due to the transfer of opioids across the placenta.

Question 32

What is the **definition of neuraxial opioids**?

Answer 32

Refers to epidural OR spinal administration ## Footnote This method targets Mu receptors in the spinal cord for analgesia.

Question 33

What is the **mechanism of action for neuraxial opioids**?

Answer 33

* Targeting Mu receptors in spinal cord * Diffusion through meninges ## Footnote This provides localized analgesia without sympathetic blockade.

Question 34

What is the effect of **highly lipid-soluble opioids** like Fentanyl in terms of onset and duration?

Answer 34

* Rapid diffusion out of CSF * Quick onset * Short duration of analgesia * Significant systemic absorption ## Footnote These characteristics influence the clinical use of opioids in pain management.

Question 35

How does the **hydrophilic nature** of opioids affect their distribution?

Answer 35

* Promotes greater spread * Stays mobile in aqueous CSF * Slower onset but longer duration and wider distribution ## Footnote Hydrophilic opioids penetrate neural tissue more slowly.

Question 36

What are the differences between **intrathecal** and **epidural** administration of opioids?

Answer 36

* Both produce rapid analgesia * Intrathecal avoids rostral spread * Reduces risk of delayed respiratory depression ## Footnote This distinction is important for managing pain and minimizing side effects.

Question 37

What is a significant risk associated with **lipophilic opioids** like Fentanyl?

Answer 37

* Early respiratory depression * Minimal rostral spread * Associated with early onset of risk ## Footnote This highlights the importance of monitoring patients after administration.

Question 38

What are common **side effects** of opioids?

Answer 38

* Pruritus * Nausea and vomiting * Urinary retention * Respiratory depression ## Footnote Side effects can vary based on the specific opioid and its dosage.

Question 39

What is the **potency** of Fentanyl compared to Morphine?

Answer 39

100 times more potent ## Footnote This high potency is due to greater receptor affinity and lipid solubility.

Question 40

What is unique about the metabolism of **Remifentanil**?

Answer 40

* Metabolized by plasma esterases * Ensures rapid clearance * Ideal for patients with liver impairment ## Footnote This characteristic allows for precise titration and rapid recovery.

Question 41

What are the **pharmacokinetics** of Sufentanil?

Answer 41

* Routes: IV * Induction: 0.1-0.3 mcg/kg * Onset: 1-3 minutes * Duration: Dose dependent * Elimination half-life: 6 hours ## Footnote Sufentanil's pharmacokinetics make it suitable for various clinical applications.

Question 42

What is the **characteristic** of Hydromorphone compared to Morphine?

Answer 42

* Approximately 7 times more potent * Shorter duration of action * Less histamine release ## Footnote This makes Hydromorphone a safer option for certain patients.

Question 43

What is the **duration** of action for Morphine when used intrathecally?

Answer 43

Longest duration of action ## Footnote Morphine's low lipophilicity prolongs its presence in CSF, providing extended analgesia.

Question 44

What are the **primary uses** of Meperidine?

Answer 44

* Analgesia during labor * Post-surgery pain management * Treating post-operative shivering ## Footnote Meperidine's unique properties make it useful in specific clinical scenarios.

Question 45

What is the **mechanism** of opioid antagonists like Naloxone?

Answer 45

* High affinity for opioid receptors * Displaces agonist from receptor * Prevents agonist activation ## Footnote This mechanism is crucial for reversing opioid overdose effects.

Question 46

What is the **characteristic** of Naltrexone?

Answer 46

* Similar antagonist properties to Naloxone * Used for alcohol withdrawal * Blocks euphoric effects of opioids ## Footnote Naltrexone's extended-release formulation is beneficial in addiction treatment.

Question 47

What is the **advantage** of Nalmefene over Naloxone?

Answer 47

Longer duration of action ## Footnote This property makes Nalmefene effective for managing opioid overdose without precipitating withdrawal.

Question 48

What are examples of **partial agonists** and **agonist-antagonists**?

Answer 48

* Pentazocine * Butorphanol * Nalbuphine * Buprenorphine * Dezocine ## Footnote These agents provide analgesia while limiting severe side effects.

Question 49

Name examples of **agonist-antagonists**.

Answer 49

* Pentazocine (Talwin®) * Butorphanol (Stadol®) * Nalbuphine (Nubain®) * Buprenorphine (Buprenex®) * Dezocine (Dalgan®) ## Footnote These medications have unique properties that differentiate them from traditional opioids.

Question 50

What is the **mechanism** of agonist-antagonists?

Answer 50

* Bind to Mu receptors with limited responses * Produce partial agonist effects * Limit risk of severe side effects like respiratory depression * Provide some analgesia ## Footnote This mechanism helps in managing pain while minimizing risks associated with full agonists.

Question 51

Agonist-antagonists exhibit **partial agonist actions** at which receptors?

Answer 51

* Kappa * Delta ## Footnote Activity at Kappa and Delta receptors contributes to analgesia but may also cause side effects like dysphoria.

Question 52

Agonist-antagonists act as **antagonists** at which receptors?

Answer 52

Mu receptors ## Footnote This antagonistic action reduces the efficacy of subsequently administered opioid agonists.

Question 53

What is the **ceiling effect** in agonist-antagonists?

Answer 53

* For analgesia and respiratory depression * Beyond certain dose, no significant increase in analgesia or respiratory depression * Enhances safety ## Footnote This effect is crucial for preventing overdose and enhancing patient safety.

Question 54

List the **clinical uses** of agonist-antagonists.

Answer 54

* Independent Use: Effective for mild to moderate pain * Combination Therapy: Combined with nitrous oxide or benzodiazepines * Partial Reversal: Can reverse unwanted effects while preserving some analgesia * Considerations: Incomplete analgesia reversal may result in sudden pain ## Footnote These uses highlight the versatility of agonist-antagonists in pain management.

Question 55

What are **NSAIDs**?

Answer 55

* Nonsteroidal Anti-Inflammatory Drugs ## Footnote They are commonly used to reduce inflammation and alleviate pain.

Question 56

Name examples of **NSAIDs**.

Answer 56

* Ketorolac * Celebrex * Ibuprofen ## Footnote These medications are widely used for their anti-inflammatory and analgesic properties.

Question 57

What is the **mechanism of action** of NSAIDs?

Answer 57

* Reduce inflammatory response * Decrease activity of cyclooxygenase (COX) 1 and/or 2 * Inhibit prostaglandin synthesis ## Footnote This mechanism is key to their effectiveness in treating pain and inflammation.

Question 58

What is a significant **consideration** when using Ketorolac?

Answer 58

Check with surgeon before giving ## Footnote This is important due to the incidence of bleeding associated with its use.

Question 59

What is the **mechanism of action** of Acetaminophen?

Answer 59

* Inhibits prostaglandin synthesis in CNS * Likely through COX-2 enzyme inhibition ## Footnote This results in analgesic and antipyretic effects, distinguishing it from NSAIDs.

Question 60

What is the **max dose** of Acetaminophen for adults?

Answer 60

4 g/day ## Footnote This dose may be decreased in patients with liver dysfunction.

Question 61

What is the **reversal agent** for Acetaminophen overdose?

Answer 61

N-acetylcysteine (Mucomyst) ## Footnote This agent is critical for treating hepatotoxicity due to Acetaminophen overdose.

Question 62

What is the **mechanism of action** of Gabapentin?

Answer 62

* Binds to voltage-gated calcium channels * Binds to N-methyl-D-aspartate (NMDA) receptors ## Footnote This mechanism is still speculative but contributes to its analgesic properties.

Question 63

What are the **clinical applications** of Gabapentin?

Answer 63

* Treatment of chronic neuropathic pain * Can be administered preoperatively to reduce postoperative opioid requirements * May contribute to postoperative sedation ## Footnote These applications demonstrate its utility in pain management.