Exam 2: 17 Feb Opioids Flashcards
What is the opioid epidemic?
A widespread issue related to the misuse of opioids, particularly highlighted in Florida
What is opioid-free anesthesia?
An approach that avoids the use of opioids during anesthesia, utilizing multimodal anesthesia techniques
What are some techniques used in opioid-free anesthesia?
- Multimodal anesthesia
- Peripheral nerve blocks
- Spinal or epidural anesthesia
What are the key properties of morphine?
- Analgesia
- Euphoria
- Sedation
- Respiratory depression
What are some common side effects of opioids?
- Respiratory depression
- Constipation
- Cardiovascular effects
What is the role of physostigmine in opioid use?
To reverse opioid-induced ventilatory depression without affecting analgesia
What is lipid solubility’s significance in opioids?
It is the primary factor affecting the onset of action of drugs
What does PK analysis stand for?
Pharmacokinetics analysis
Fill in the blank: The primary factors affecting the onset of action of opioids include _______.
[lipid solubility]
What are the three main opioid receptors?
- Mu
- Delta
- Kappa
What are the effects produced by mu receptors?
- Analgesia
- Euphoria
- Sedation
- Respiratory depression
What is the time course of opioid withdrawal?
Includes initial symptoms that vary in severity over time
What is the significance of understanding opioid withdrawal?
It is crucial for clinical practice and managing patient care
What is the origin of opiates?
Derived from the Papaver somniferum plant
What is the historical misconception about heroin?
Initially thought to not cause addiction
What are agonist-antagonist opioids used for?
Managing dependence and tolerance
True or False: Fentanyl has a slower onset than morphine.
False
What is the primary use of naloxone?
To reverse opioid overdose
What are the structural categories of opioids?
- Phenanthrenes
- Benzyl isoprenylamines
What is the significance of understanding opioid pharmacokinetics?
It ensures safe and effective anesthesia practice
What is the relationship between opioid dosing and protein binding?
Protein binding affects the distribution and elimination of opioids
What are some routes of administration for opioids?
- IV
- PO
- Peripheral nerve blocks
What is the clinical use of hydromorphone?
Post-operative pain management
What is the importance of monitoring patients on opioids?
To avoid adverse effects such as respiratory depression
What does the term ‘enhanced recovery’ refer to?
An approach to surgical procedures that avoids opioids
What are opioid receptors responsible for?
Mediating therapeutic analgesic effects and side effects of opioid medications
Where are opioid receptors located?
In the brain and dorsal horn of the spinal cord, including areas like the thalamus and perioperative brain
What types of receptors do opioids act as agonists on?
Mu (μ), Delta (δ), and Kappa (κ) receptors
What are the primary effects of mu receptors?
- Analgesia
- Euphoria
- Sedation
- Respiratory depression
- Decreased peristalsis (leading to constipation)
What is the effect of delta receptors in the brain?
May have a hallucinogenic effect and cause decreased gastrointestinal secretions
What is the role of Kappa receptors?
Mediates dysphoria by reducing dopamine release
What is the primary mechanism of opioids?
Act as agonists at specific opioid receptors
What neurotransmitters are inhibited by opioid receptors?
- Acetylcholine
- Dopamine
- Norepinephrine
- Substance P
What is the effect of opioids on neurotransmission?
Decreased neurotransmission, leading to modulation of pain
Where in the spinal cord are opioid receptors specifically found?
In interneurons and primary afferent neurons in the dorsal horn, especially in the substantia gelatinosa
What is the direct application of opioids in clinical practice?
To produce intense analgesia
What is the typical dosage range for spinal fentanyl?
10 to 25 micrograms
What are some common side effects of opioids?
- Bradycardia
- Hypothermia
- Urinary retention
- Constipation
Which receptor is associated with high physical dependence?
Mu (μ) receptor type 2
What cardiovascular effects can opioids have?
- Decreased sympathetic nervous system tone
- Decreased venous return
- Decreased cardiac output
- Orthostatic hypotension
What is a potential complication of opioid overdose?
Respiratory depression
What is the significance of maintaining patients within 20% of their baseline vitals?
To avoid hemodynamic instability during opioid administration
What can result from opioid-induced ventilation depression?
Decreased responsiveness of ventilation centers to carbon dioxide
What is the effect of opioids on the PA CO2 curve?
Shifts to the right
What is the role of physostigmine in opioid administration?
Antagonizes ventilatory depression without affecting analgesic properties
What kind of drug is dextromethorphan?
A cough suppressant with no analgesic effect
What is a common patient reaction to fentanyl during conscious sedation?
Reflex coughing
What happens to cerebral blood flow with opioid administration?
Decreases, potentially affecting intracranial pressure (ICP)
What should be monitored during emergence from anesthesia?
Pupil constriction to assess for potential opioid overdose
What does a shift to the right in the PA CO2 curve indicate?
Increased CO2 levels required for ventilation
True or False: Naloxone is a complete reversal agent for all anesthetic agents.
False
Fill in the blank: Opioids can be used in conjunction with _______ to produce intense analgesia.
Local anesthetics
What should be cautioned when administering opiates?
Administration of opiates must be cautious due to effects on wakefulness, meiosis, and potential myoclonus in head injury patients.
Opiates can cross the blood-brain barrier and have significant CNS effects.
What is the effect of opioids on respiratory rate compared to volatile anesthetics?
Opioids decrease respiratory rate, while volatile anesthetics increase it.
This contrast is crucial during patient emergence from anesthesia.
What is the treatment for skeletal thoracic muscle rigidity caused by opioids?
The treatment is to administer muscle relaxants or reverse the fentanyl with naloxone.
Naloxone is a pure antagonist that can help reverse opioid effects.
What percentage of patients experience sedation with opioids during titration?
Sedation occurs in 60% of patients during opioid titration.
This is an important consideration for post-operative care.
Fill in the blank: The opioid that is considered the gold standard is _______.
morphine.
What are the common side effects of morphine?
Common side effects include:
* Analgesia
* Euphoria
* Sedation
* Nausea
* Flushing
* Delayed gastric emptying
Morphine can also cause diminished ability to concentrate and heaviness of extremities.
What is the typical onset time for morphine when administered IV?
The onset time is 10 to 20 minutes.
What is the peak effect time for morphine?
The peak effect time is 45 to 90 minutes.
What happens to opioid receptors with prolonged use?
There is down-regulation and desensitization of opioid receptors, leading to tolerance.
This typically occurs within two to three weeks.
True or False: Glucagon can antagonize opioids.
False.
What is the maximum dose of glucagon that can be given incrementally?
The maximum dose is 2 milligrams.
What are the effects of glucagon related to gastric emptying?
Glucagon may increase gastric emptying, causing diarrhea or vomiting.
It is important to titrate glucagon carefully.
Fill in the blank: The primary goal of non-opioid anesthesia is to keep patients _______.
opioid free.
What is the elimination half-life of morphine affected by in renal dysfunction?
Elimination half-life is prolonged in renal dysfunction.
What should be monitored closely when titrating morphine?
Blood pressure should be monitored closely to avoid hypotension.
What is the typical duration of action for morphine?
The duration of action is 4 to 5 hours.
What is the effect of opioids on gastrointestinal motility?
Opioids cause delayed gastric emptying and may lead to nausea and vomiting.
What is the recommended initial dose of morphine for titration?
The recommended initial dose is 1 to 10 milligrams IV.
What is the risk associated with administering high doses of intraoperative opioids?
Higher doses can lead to greater post-operative pain.
This is why there is a shift towards opioid-free anesthesia.
What is the role of naloxone in opioid administration?
Naloxone is used to reverse the effects of opioids.
What is the effect of opioids on the CNS?
Opioids cause sedation and can affect ventilatory drive.
What are the potential neonatal effects of opioid administration during pregnancy?
Neonatal depression and dependence can occur.
What is the dilution ratio for morphine to achieve one milligram per ml?
Dilute morphine to one milligram per ml
This involves adjusting the concentration appropriately.
What is the typical administration interval for morphine during emergence?
15 to 30 minutes
This is monitored over three blood pressure cycles.
What are the potential side effects of morphine?
- Pleuritis
- Bradycardia
- Hypotension
- Post-operative nausea
- Vomiting
- Promotion of ileus
Why is morphine losing favor in anesthesia?
It is too long-acting and not favorable for opioid-free anesthesia
The trend is moving towards minimizing opioid use.
What is the potency comparison of meperidine to morphine?
Meperidine is 110 times as potent as morphine
This refers to its analgesic effect.
What is the typical dose of meperidine for post-operative shivering?
12.5 to 25 milligrams
Usually given as half a milliliter of 25 mg/ml solution.
What physiological effect does shivering have on oxygen utilization?
Increases oxygen consumption by 500%
This can lead to decreased oxygenation to vital organs.
What are the side effects of meperidine?
- Sedation
- Euphoria
- Nausea and vomiting
- Respiratory depression
What is the elimination half-life of meperidine?
3 to 5 hours
Prolonged to 35 hours in renal failure.
What is the mechanism of action for meperidine?
Agonist at mu and kappa opioid receptors
Also acts on alpha-2 receptors.
Fentanyl is how many times more potent than morphine?
7125 times more potent
This highlights its strong analgesic properties.
What is the equilibration time for fentanyl in the body?
6.4 minutes
This is the time it takes for fentanyl to reach effective concentrations.
What is the context-sensitive half-time for fentanyl infusions?
Remains stable with prolonged infusion durations
This means the duration of action does not significantly increase.
What is the primary metabolism pathway for fentanyl?
CYP 450 enzymes, specifically CYP3A4
The principal metabolite is norfentanyl.
What is the first-pass effect for fentanyl in the lungs?
75%
This highlights the significant extraction and accumulation of fentanyl in the pulmonary circulation.
What are the potential side effects of fentanyl?
- Delirium
- Confusion
- Hallucinations
- Myoclonus
- Seizures
How does fentanyl affect elderly patients?
Requires careful titration due to lower fat content
Elderly patients may experience increased effects due to different pharmacokinetics.
What is the typical IV induction dose of fentanyl?
1.5 to 3 micrograms per kilogram
Administered five minutes prior to intubation.
What is the role of fentanyl in relation to inhaled anesthetics?
Used as an adjunct to enhance analgesia
Especially useful during inhalation inductions for pediatric patients.
What is the primary reason not to use fentanyl during cardiopulmonary bypass?
Significant absorption in the bypass circuit
This can affect the drug’s efficacy and dosing.
What is the purpose of anticipating changes in surgical stimulation during pediatric inhalation inductions?
To adjust anesthesia levels accordingly, such as administering more fentanyl.
What is the recommended dosage range for fentanyl as a solo anesthesia in pediatric patients?
50 to 150 mcg/kg IV.
What are some drugs that can be used intrathecally?
- Bupivacaine
- Lidocaine
- Morphine
- Demerol
Fill in the blank: One milligram of oral fentanyl is equivalent to _______ milligrams of IV morphine.
5.
What are some forms of oral transmucosal drugs used in pediatrics?
- Lozenges
- Rapidly dissolving film
- Lidocaine lollipops
What is a significant risk when administering fentanyl to patients with transdermal patches?
Hypotension due to cumulative effects.
True or False: Fentanyl causes significant bradycardia.
False.
What is the effect of high doses of fentanyl on intracranial pressure (ICP)?
Modest increase in ICP of 6 to 9.
What is the potency comparison of sufentanil to fentanyl?
5 to 12 times more potent than fentanyl.
What are the primary routes of metabolism and excretion for sufentanil?
- Hepatic metabolism
- Renal and fecal excretion
What is the onset time for alfentanil compared to fentanyl?
1.4 minutes faster than fentanyl.
What is the elimination half-life of remifentanil?
6.3 minutes.
What is the primary metabolism pathway for remifentanil?
Hydrolysis by non-specific plasma and tissue esterases.
Fill in the blank: Remifentanil is _______ times more potent than fentanyl.
15 to 20.
What are some common side effects of remifentanil?
- Nausea
- Vomiting
- Respiratory depression
- Decreased heart rate
What is the recommended use of hydromorphone?
As a postoperative analgesic.
What is the potency of hydromorphone compared to morphine?
5 to 10 times more potent than morphine.
True or False: Methadone is widely used in anesthesia.
False.
What is the elimination half-life of hydromorphone?
3 to 3.5 hours.
What are the primary receptors targeted by opioid agonists such as hydromorphone?
Mu receptors.
What should be monitored when using fentanyl in an epidural or IV setting?
Hemodynamics and potential for chest rigidity.
What is the clinical use of alfentanil?
Induction and maintenance of anesthesia.
What is a key consideration when using opioids in patients with chronic renal failure?
Caution due to altered excretion.
What is the mechanism of action shared by oxymorphone, oxycodone, and hydrocodone?
They act on the same receptors as other opioid agonists.
In what contexts is methadone primarily used?
Opioid withdrawal and chronic pain.
What is the typical dosage comparison of tramadol to morphine?
Five to ten times less than morphine.
What are the main receptors targeted by tramadol?
Weak Kappa and Delta.
What is the onset time for tramadol when administered orally?
Three minutes per kid.
True or False: Tramadol has no potential for addiction.
False.
Which opioid has the fastest blood-brain equilibration time?
Fentanyl, taking only 1.1 minutes.
What is the primary factor affecting the onset of action for opioids?
Effect site equilibration.
List the factors that influence the drug’s onset of action.
- Volume of distribution
- Clearance
- Protein binding
- Percent ionized
- PK of the drug
- pH of the patient
What does lipid solubility have the highest effect on?
Effect site equilibration.
What should be considered when administering opioids?
The route of administration (IV, PO, intrathecal, etc.) and target receptors.
What is the significance of comparing morphine versus fentanyl?
To analyze their differences in efficacy and onset times.
What is recommended for group discussions regarding the opioid table?
Identify the worst and best drugs based on various parameters.
What was the conclusion of the agonist section?
The discussion on opioid agonists and their characteristics.
What time was the break scheduled during the session?
1255.
Fill in the blank: The _______ component is used in opioid withdrawal and chronic pain.
cannabinoids
