Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

NBB1 > Opioid Pharmacology > Flashcards

Opioid Pharmacology Flashcards

1
Q

What’s the difference between an opiate and an opioid?

A

Opiate: naturally occurring
Opioid: any natural, synthetic or semi-synthetic compound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is an alkaloid?

A

a class of naturally occurring organic-nitrogen containing bases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How do we classify opioids?

A
  1. Interaction with opioid receptor subtypes: mu, kappa, delta
  2. Intrinsic activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What type of receptors are opioid receptors?

A
  • all are G-protein coupled receptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the 3 levels of intrinsic activity of opioids?

A

Pure agonists, pure antagonists and mixed agonist-antagonists

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How can we characterize mixed agonist-antagonists?

A

Kappa agonists: produce analgesia

Mu antagonists: interfere with morphine, heroin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the endogenous opioid peptides?

A

endorphins, enkephalins, dynorphins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Where are opioid peptides located and what is their function?

A

Brain: NTs and neuromodulators

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the function of endogenous opioid peptides?

A

Modulate pain transmission in spinal cord

Alter acetylcholine release in GI myenteric plexus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Where do beta-endorphins come from?

A

Cleavage product of POMC, precursor hormone for ACTH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the acute effects of opioids?

A 
analgesia
respiratory depression
euphoria
cough suppression
miosis
constipation
increased IC pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are the chronic effects of opioids?

A

tolerance

physical dependence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the special acute effect of meperidine/demerol?

A

mydriasis (pupil dilation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a one difference between opioid types with regard to acute effect?

A

histamine release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is clinical selection of an opioid based on?

A

Pharmacokinetics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the main use of opioids in the clinic?

A

1 Analgesia for moderate to severe pain (morphine/heroin)
2 Analgesia for moderate long-term chronic pain (oxycodone or hydrocodone)
3 Anesthesia (fentanyl)
4 cough suppressant (dextromethorphan/codeine)
5 diarrhea relief (diphenoxylate or loperamide, decreased BBB penetration)
6 acute pulmonary edema (morphine)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the most important use of morphine today?

A

myocardial infarction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When are opioids contra-indicated?

A

head injuries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What do you use if a cancer patient becomes tolerant to morphine?

A

fentanyl IM/IV

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How do opioids act centrally for analgesia/mood?

A

inhibit transmission and processing of pain signals (emotional response altered in limbic cortex)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How do opioids act peripherally for analgesia/mood?

A

On sensory neurons, particularly helpful for patient’s with tissue inflammation and nerve ending damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are the clinical characteristics of opioids?

A

Selective analgesia without hypnosis, sedation or impaired sensation
Mood elevation or euphora can occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What types of pain are best treated by opioids?

A

Prolonged burning pain (vs. sharp pain of incision)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What type of pain is NOT helped by opioids?

A

Neuropathic pain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is the mechanism of euphoria created by opioids?

A

Suppress the release of GABA, which stimulates dopamine release in a neighboring neuron

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the side effects of opioids experienced in the CNS?

A

Drowsiness, heaviness, difficulty concentrating

Sleep

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Why are opioids contra-indicated in head injury?

A

1 may exacerbate damage caused to the respiratory center in brain
2 nausea, miosis and CNS clouding caused by opioids can confuse the neurologic eval

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

How do opioids induce respiratory depression?

A
  • Directly affect respiratory centers in medulla causing decreased sensitivity to increasing blood levels of CO2
  • increased CO2 causes cerebral vasodilation –> increased IC pressure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the major toxicity of opioids?

A

Respiratory depression - almost always cause of death from overdose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

How does sleep affect the response to CO2?

A

Depresses the response, potentiates opioid effect

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How does dose affect respiratory depression?

A

Effects are dose-related. Very large doses can cause apnea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Are respiratory depression and analgesia interlinked?

A

YES. Direct correlation, hard to reverse depression w/o losing analgesic effects

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

How do opioids suppress cough?

A

Depression of cough centers in the medulla (different mechanism from analgesia/resp. depression)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What type of opioids suppress cough? Do they have analgesic activity?

A

d-isomers of opioids, and no

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What are the 2 agents that suppress cough?

A

Codeine or dextromethorphan

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

How do opioids constrict pupils?

A

Stimulation of Edinger-Westphal (PSNS) nucleus of CN III

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is a telltale sign of opioid overdose?

A

Miosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

How can we reverse opioid overdose?

A

Naloxone, atropine or ganglionic blockers (mecamylamine)

39
Q

How do opioids induce nausea and vomiting?

A

Stimulate the chemoreceptor trigger zone to activate the vomiting center

40
Q

Which population is most likely to vomit from opioids?

A

Ambulatory patients vs. supine because emetic effects are potentiated by stimulation of the vestibular apparatus

41
Q

How do opioids affect skeletal muscles?

A

large IV doses may cause stiffness of skeletal muscle

42
Q

What is the mechanism of the effect in skeletal muscle?

A

mu-mediated increase in striatal dopamine synthesis and inhibition of striatal GABA release

43
Q

Which opioid is most likely to cause skeletal muscle stiffness?

A

Fentanyl

44
Q

How do opioids affect HR? Mechanism?

A

Cause bradycardia by stimulation of central vagal nerve

45
Q

What other CV effects result from opioid use?

A

Decreased sympathetic tone –> vasodilation, orthostatic hypotension

46
Q

Which opioids cause histamine release? What are the downstream effects?

A

Morphine, fentanyl and merperidine

Vasodilation and hypotension

47
Q

What are side effects of histamine release? Is this an allergy?

A

Skin redness, urticaria (hives/rash) and pruritis (itchy skin)
NO

48
Q

What is the mechanism of constipation?

A

Spasm of smooth muscle in GI tract
Diminished rhythmic propulsive activity (peristalsis)
Delayed gastric emptying

49
Q

What opioids are used for diarrhea? Why are they good?

A

Diphenoxylate and loperamide

Poorly CNS-absorbed

50
Q

How do opioids affect the biliary system?

A

Contract smooth muscle along biliary tree, spasm the spinchter of Oddi
May precipitate biliary colic (gall stones)

51
Q

How can we antagonize the effects on the biliary system?

A

Naloxone

Partially reversed by glucagon, nitroglycerin or atropine

52
Q

How do opioids affect the urinary tract?

A

Anti-diuretic –> urinary retention

53
Q

How are opioids used in pregnancy?

A

Sometimes used sparingly - relieve labor pain

54
Q

What are concerns with opioids used in pregnancy?

A
  • Cross the placenta - may cause resp. depression in baby

- Chronic use in utero may cause physical dependence and subsequent neonatal withdrawal after delivery

55
Q

How does tolerance develop over time?

A

Adaptive response of AC and/or G protein coupling (Not a PK effect)

56
Q

How does tolerance develop w/ respect to other opioids?

A

Additively!

57
Q

What is the order of effects to which patients become tolerant?

A

Rapidly: depressant: analgesia, resp. depression, euphoria

More slowly: stimulatory effects: miosis, constipation

58
Q

How can we apply the differential tolerance mechanisms to a) heroin addicts?

A

A) heroin addicts/methadone patients:

  • Little euphoria from high doses
  • still get constipation/miosis
59
Q

How can we apply the differential tolerance mechanisms to b) cancer patients?

A

B) terminal cancer patients requiring high doses for analgesia

  • tolerant to respiratory depression
  • require laxatives for constipation
60
Q

When does withdrawal occur?

A

Withdrawal or abstinence syndrome occurs when the drug is stopped = physical dependence

61
Q

How do you stop withdrawal?

A

Give a small dose of opioid

62
Q

What does giving antagonist to a physically dependent person do?

A

Causes rapid onset of more severe withdrawal syndrome

63
Q

What are the symptoms of withdrawal?

A

sweating, runny nose, vomiting, diarrhea, piloerection (goose bumps), mydriasis, shaking chills, drug seeking behavior

64
Q

What is the difference between physical dependence and psychological dependence?

A

Physical: natural need for higher dose of analgesia

Psychological dependence: addiction, craving a high

65
Q

What is methadone used for?

A

Long-acting opioid used for detox to wean an addicted individual off of morphine, heroin, etc.

66
Q

What are the properties of methadone?

A
  • Longer half life (24-35 hours)
67
Q

What are the withdrawal effects of methadone?

A
  • Withdrawal effects: protracted, but milkd
68
Q

How does one taper off of methadone?

A

Must be tapered slowly to avoid risk of acute withdrawal, craving, abuse

69
Q

What are the benefits of methadone?

A

1 Intensity of withdrawal symptoms decreased (also drug seeking/illegal activity)
2 Tolerance develops to opioid euphoria - so injection of heroin is not reinforcing
3 ORAL - no needle use
4 obtaining methadone requires regular contact to caregivers, access to counseling

70
Q

What is the classic triad of opioid overdose?

A

miosis
apnea
stupor (coma)

71
Q

What is the defining symptom of opioid overdose?

A

Respiratory depression

72
Q

What is a later clinical manifestation of opioid overdose?

A

Pulmonary edema

73
Q

When do seizures occur with overdose?

A

Only occasionally, with mperidine, pentazocine/naloxone

74
Q

What are the PK of morphine?

A
  • Rapid absorption, wide distribution, rapid hepatic clearance (70% first pass metabolism)
  • Hydrophilic: CNS penetration/exit are slow = slow onset and long duration
75
Q

How is heroin different than morphine w/ regard to PK?

A

Heroin: more lipophilic –> faster CNS penetration!
Morphine: hydrophobic

76
Q

What are the PK of fentanyl?

A
  • Rapid absorption, wide distribution, short T1/2 (>60% first pass metabolism)
  • Lipophilic - rapidly crosses BBB
  • Multiple delivery routes
77
Q

Which is more powerful, morphine or fentanyl?

A

Fentanyl: 80-100 times more powerful

78
Q

What considerations are there for dosing opioids?

A
  • Requirements vary per patient

- Narrow therapeutic window

79
Q

Who should receive lower doses of opioids?

A 
Elderly
hypovolemic
debilitated
hypothyroid
those taking CNS depressants
80
Q

Which two opioids that include acetaminophen?

A

Vicodin: hydrocodone / acetaminophen
Percocet: oxycodone/ acetaminophen

81
Q

What is important to monitor in acetaminphen/opioid combinations?

A
  • Limit acetaminophen to
82
Q

How is naloxone administered?

A

IV or IM

83
Q

How is naltrexone administered?

A

orally

84
Q

What is the goal of naloxone?

A

To reverse opioid overdose, including resp. depression

85
Q

What are side effects of naloxone?

A

May induce withdrawal

86
Q

What is the goal of naltrexone?

A

Used for maintenance therapy and relapse prevention

87
Q

What is the goal of opioid partial agonists or mixed agonist-antagonists?

A

To find drugs with:

  • less abuse potential
  • decreased respiratory depression
88
Q

What is the action of opioid partial agonists or mixed agonist-antagonists?

A
  • Analgesic properties

- Antagonize morphine effects

89
Q

How does Buprenorphine work?

A

partial agonist at mu receptor

90
Q

What is the goal of Buprenorphine? What is the formulation?

A
  • maintenance therapy for opioid/alcohol dependence when added to naloxone
91
Q

What are are the mixed agonist-antagonists?

A

nalorphine
pentazocine
nalbuphine
butorphanel

92
Q

What is the action of mixed agonist-antagonists?

A

Act as kappa agonists to produce analgesia, also mu antagonists

93
Q

What is a caution of mixed agonist-antagonists?

A

Also mu antagonists, so can induce acute withdrawal in heroin or morphine addicts

NBB1 (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions