Basics Chapter 10

Front 1

Define opiods

Back 1

all exogenous substances, natural and synthetic, that bind specifically to opiod receptors and produce some agonist (morphine like) effects

Front 2

What is potency of opiods related to?

Back 2

The stereochemical structure of the molecule.

*Levo-isomers are most active

Front 3

List and describe the three types of opiods

Back 3

1) Naturally occuring= Levoisomer or L-Morphine
2) Semisynthetic=
result from minor modification of morphine molecule
3) Synthetic=
contain phenanthrene nucleus of morphine but are manufactured by synthesis rather than chemical modification of morphine.

Front 4

What are the principal pharmacodynamic differences between opiod drugs?

Back 4

1) potency
2) rate of equilibration between plasma and site of drug effect

Front 5

Where are the opiod receptors located in the body?

Back 5

1) Stereospecific Opiod Receptors in the CNS

2) Outside the CNS in peripheral tissues.

Front 6

What is the mode of action of Opiods?

Back 6

Opiods mimic the actions of endogenous peptide opiod receptor ligands (endorphins) by binding to opiod receptors

Front 7

What does binding of opiods to their receptors result in?

Back 7

Activation of Pain-modulating (antinocieptive) systems.

Front 8

What are the effects of opiod receptor activation?

Back 8

1) Primary effect is decrease in neurotransmission (results from presynaptic inhibition of neurotransmitter release such as AcH, dopa, norepi, substance p)

2) Increased potassium conductance, leading to hyperpolarization of cellular membranes.

Front 9

What does depression of cholinergic transmission in the CNS result in?

Back 9

Opiod induced inhibition of acetylcholine release from nerve endings, producing significant analgesic and otherh side effects (depression of ventilation)

Front 10

What are the four classifications of Opiod receptors?

Back 10

Mu1, Mu 2, Delta, Kappa

Front 11

What are the four classifications of Opiod receptors?

Back 11

Mu1, Mu 2, Delta, Kappa

Front 12

List the Effects, associated with Mu1 receptors.

Back 12

Effects: Analgesia (supraspinal, spinal), Euphoria, Low abuse potential, Miosis, Bradycardia, Hypothermia, Urinary retention.

Front 13

List the agonists associated with Mu1 receptors.

Back 13

Endorphins, Morphine, Synthetic Opiods.

Front 14

List the Antagonists associated with Mu1 Receptors.

Back 14

Naloxone, Naltrexone, Nalmefene.

Front 15

List the Effects associated with Mu2 receptors.

Back 15

Analgesia (spinal), Depression of ventilation, physical dependence, constipation (marked)

Front 16

List the Agonists associated with Mu2 receptors.

Back 16

Endorphins, Morphine, Synthetic opiods.

Front 17

List the Antagonists associated with Mu2 receptors

Back 17

Naloxone, Naltrexone, Nalmefene

Front 18

List the effects associated with Kappa opiod receptors.

Back 18

Analgesia (supraspinal, spinal), Dysphoria, sedation, low abuse potential, diuresis.

Front 19

List the agonist associated with Kappa opiod receptors

Back 19

Dynorphins

Front 20

List the antagonist associated with Kappa opiod receptors

Back 20

Naloxone, Naltrexone, Nalmefene

Front 21

List the effects associated with Delta opiod receptors

Back 21

Analgesia (supraspinal, spinal), Depression of ventilation, physical dependence, constipation, urinary retention.

Front 22

List the agonists associated with Delta opiod receptors

Back 22

Enkephalins

Front 23

List the antagonists associated with Delta opiod receptors

Back 23

Naloxone, Naltrexone, Nalmefene

Front 24

Describe absorption of opiods placed in the epidural space.

Back 24

Opiods placed in the epidural space undergo significant systemic absorption and passage into the subarachnoid space.

Front 25

Describe absorption of opiods placed in the epidural space.

Back 25

Opiods placed in the epidural space undergo significant systemic absorption and passage into the subarachnoid space.

Front 26

What influences penetration of opiods in the dura?

Back 26

Lipid solubility of the agent (ie. fentanyl and sufentanil pass across the dura much more rapidly than morphine)

Front 27

Compare epidural and intramuscular injections of equivalent doses of opiods.

Back 27

Epidural administration of morphine, Fentanyl, sufentanil produce opiod blood concentrations simaler to that of IM injections of equal dose

Front 28

Is vascular absorption after intrathecal administration significant?

Back 28

no

Front 29

What determines rate or amount of cephalad (toward head) movement of opiods in CSF? Give Example.

Back 29

depends on lipid solubility
example: Lipid-soluble opiods (fentanyl, sufenta), are limited in cephalad migration by uptake into the spinal cord, whereas less lipid-soluble morphine remains in CSF for transfer to more cephalad locations.

Front 30

What are the Side Effects of Neuraxial Opiods?

Which are most common?

Back 30

table 10-3
1) Pruritis
2) N/V
3) Urinary retention
4) Depression of ventilation
5) Sedation
6) Central Nervous system excitation
7) Activation of latent viral infections
8) Sexual dysfunction
9) Water Retention

most common=1-4

Front 31

What is the primary cause of opiod sideffects?

Back 31

SE result from the presence of the drug in the CSF or systemic circulation, or both

Front 32

List and describe the stages of depression of ventilation associated with neuraxial injection of opiods.

Back 32

1) Early: occurs within 2 hours
2) Delayed: occurs 6-12 hours after epidural or intrathecal administration of morphine.

Front 33

What opiod receptors are present in the spinal cord?

Back 33

Opiods placed in the epidural or subarachnoid space bind to mu erceptros in teh substantia gelatinosa of the spinal cord.

Front 34

Contrast analgesia obtained by neuraxial opiods vs iv opiods

Back 34

Unlike IV opiods, analgesia produced by spinal or epidural (neuraxial) opiods is not associated with sympathetic nervous system denervation, skeletal muscle weakness, or loss of proprioception.

Front 35

Analgesia in Neuraxial opiods is dose related compare epidural and subarachnoid doses and effects

Back 35

epidural dose is 5 to 10 times that of subarachnoid dose, adn specific for visceral rather than somatic pain

Front 36

Describe the steps following action of epidural placement of opiods which result in analgesia

Back 36

1) Diffuses across Dura
2) Binds to Mu opiod receptors on the spinal cord
3) absorbs systemically to produce effects simalar to that of IV administration

Front 37

What is the difference in poorly vs highly lipid soluble agents?

Back 37

Poorly lipid soluble opiods (morphine) result in a slower onset of analgesia but have a longer duration of action than lipid soluble (fent, sufenta)

Front 38

List the Factors that increase the risk of Depression of Ventilation

Back 38

1) High opiod dose
2) Low lipid solubility of opiods
3) Concomitant administration of parenteral opiods or other sedatives
4) Lack of opiod tolerance
5) Advanced age
6) Patient position
7) Increased thoracic pressure

Front 39

List signs and symptoms of respiratory depression in neuraxial opiods.

Back 39

*note-arterial hyoxemia and hypercarbia may develop despite a normal breathing rate*
1) Pulse Ox
2) Capnography
3) Hypoventilation
4) Decreased LOC caused by hypercarbia (most reliable according to book)

Front 40

reversal agent in OD of neural axial opiods?

Back 40

Naloxone (O.25 mcg/kg/min) IV

Front 41

List opiod agonists and their half life in hrs.

Back 41

Morphine, 1.7-3.3
memperidine, 3-5
fentanyl, 3.1-6.6
sufentanil, 2.2-4.6
alfentanil, 1.4-1.5
remifentanyl, 0.17-0.33

Front 42

What is the most notable feature in teh clinical use of Opiods?

Back 42

The extraordinary variation in dose requirements to achieve analgesia

Front 43

Describe the effects of morphine

Back 43

analgesia, euphoria, sedation, decreased ability to concentrate

Front 44

Describe the effects of morphine

Back 44

analgesia, euphoria, sedation, decreased ability to concentrate

Front 45

How does morphine effect the sensaton of pain?

Back 45

Increases threshold to pain, modifies perception of noxious stimuli so it is no longer experienced as pain.

Front 46

On which type of pain does morphine work best?

Back 46

Continuous, dull pain rather than sharp, intermittent pain, pain arising from the viscera, as well as from skeletal muscles, joints, and integumental structures.

Front 47

When should opiods be administered to produce the most prominent analgesia?

Back 47

Prior to painful stimulus, (preemptive analgesia). or before acute surgical stimulus

Front 48

What can occure if Morphine is administered in the absence of pain

Back 48

dysphoria rather than euphoria

Front 49

How are opiods cleared primarily

Back 49

hepatic metabolism

Front 50

List onset, peak effects, and duration of action of morphine (IM vs IV)

Back 50

MS:
IM-onset 15-30 min
-peak 45-90 min
-duration of action 4 hours
IV-peak 15-30 min