Pharm-Exam 4- NMBD Reversals Flashcards
Which factor may significantly prolong the duration of neuromuscular blockade and hence affect the reversal?
A) Hypothermia
B) Metabolic alkalosis
C) Hypokalemia
D) Hypoglycemia
Answer: A) Hypothermia
Rationale: Hypothermia can impair the metabolism and excretion of neuromuscular blocking drugs (NMBDs) and reduce the efficacy of acetylcholinesterase, thereby prolonging the neuromuscular blockade. It decreases enzyme activity and can therefore slow the reversal process.
How does metabolic acidosis influence the reversal of NMBD?
A) It enhances the effect of NMBDs by increasing receptor sensitivity.
B) It has no significant effect on NMBD reversal.
C) It speeds up the reversal of NMBD by enhancing metabolism.
D) It can interfere with the reversal of NMBD by affecting drug ionization and distribution.
Answer: D) It can interfere with the reversal of NMBD by affecting drug ionization and distribution.
Rationale: Metabolic acidosis can affect the ionization and distribution of drugs in the body, which in turn may impair the action of NMBD reversal agents. Acidosis can decrease the binding of non-depolarizing NMBDs to the nicotinic receptors, potentially requiring higher doses of reversal agents.
Which of the following patient conditions does NOT directly impact the effectiveness of NMBD reversal agents?
A) Metabolic acidosis
B) Respiratory acidosis
C) Hyperthermia
D) Hypothermia
Answer: C) Hyperthermia
Rationale: The list from the slide specifies hypothermia as a condition that can influence NMBD reversal. There is no mention of hyperthermia. While hyperthermia may have its own effects on drug metabolism and patient condition, it is not listed as a factor in the context of this slide.
The choice of which NMBD was used is a critical factor in selecting an appropriate reversal agent. Which of the following scenarios would be a consideration in this decision-making process?
A) The duration of action of the NMBD.
B) The color of the NMBD solution.
C) The cost of the NMBD.
D) The preference of the surgical team.
Answer: A) The duration of action of the NMBD.
Rationale: The pharmacokinetics of the NMBD, including its duration of action, is crucial in choosing an appropriate reversal agent. Short-acting, intermediate-acting, and long-acting NMBDs are reversed differently, often with different dosages and types of reversal agents.
What is the primary chemical composition of Sugammadex?
A) α-cyclodextrin
B) β-cyclodextrin
C) γ-cyclodextrin
D) δ-cyclodextrin
Answer: C) γ-cyclodextrin
Rationale: Sugammadex is made of γ-cyclodextrin, which is a cyclic oligosaccharide composed of dextrose units. It has a lipophilic core and a hydrophilic exterior which allows it to encapsulate aminosteroid neuromuscular blockers like rocuronium.
What characteristic of Sugammadex allows it to be highly effective in the aqueous environment of the bloodstream?
A) High lipid solubility
B) High water solubility
C) High protein binding
D) High calcium chelation
Answer: B) High water solubility
Rationale: Sugammadex is highly water-soluble, which facilitates its rapid action in the bloodstream. Its solubility allows it to quickly come into contact with and encapsulate the neuromuscular blocking agents, reversing their effects.
Sugammadex reverses neuromuscular blockade through what mechanism?
A) Degradation of the neuromuscular blocking agent
B) Displacement of the neuromuscular blocking agent from the receptor
C) Encapsulation of the neuromuscular blocking agent
D) Renal excretion of the neuromuscular blocking agent
Answer: C) Encapsulation of the neuromuscular blocking agent
Rationale: Sugammadex works by encapsulating the aminosteroid neuromuscular blocking agents within its molecular structure, effectively removing them from the neuromuscular junction and reversing their paralytic effects.
From which source is the fundamental structure of Sugammadex derived?
A) Lactose
B) Maltose
C) Starch
D) Glycogen
Answer: C) Starch
Rationale: Sugammadex is derived from γ-cyclodextrin, which is a substance made from dextrose units from starch. This gives it the structure necessary to bind and inactivate aminosteroid neuromuscular blockers.
What types of interactions contribute to the mechanism of action of Sugammadex?
A) Electrostatic and covalent bonds
B) Ionic bonds and Van der Waals forces
C) Van der Waals forces, thermodynamic (hydrogen) bonds, and hydrophobic interactions
D) Covalent bonds and hydrophilic interactions
Answer: C) Van der Waals forces, thermodynamic (hydrogen) bonds, and hydrophobic interactions
Rationale: Sugammadex’s mechanism of action involves several non-covalent interactions such as Van der Waals forces, hydrogen bonding, and hydrophobic interactions, which facilitate the tight encapsulation of the aminosteroid neuromuscular blockers, particularly rocuronium and vecuronium.
Which neuromuscular blocking agent has the highest affinity for Sugammadex?
A) Vecuronium
B) Rocuronium
C) Pancuronium
D) Atracurium
Answer: B) Rocuronium
Rationale: Sugammadex has a greater affinity for rocuronium over vecuronium and much more so over pancuronium. This is due to the specific molecular interactions that allow Sugammadex to encapsulate rocuronium very tightly.
Sugammadex is known to bind to which of the following in the plasma?
A) Protein-bound drug
B) Ionized drug
C) Free drug
D) Metabolized drug
Answer: C) Free drug
Rationale: Sugammadex works by binding to the ‘free drug’ in plasma – that is, it binds to the unbound, active form of the neuromuscular blocking agents, thereby inactivating them.
What is the primary mechanism of action (MOA) of Sugammadex?
A) Inhibition of acetylcholinesterase
B) Activation of nicotinic acetylcholine receptors
C) Encapsulation of neuromuscular blocking agents
D) Blockade of muscarinic acetylcholine receptors
Answer: C) Encapsulation of neuromuscular blocking agents
Rationale: Sugammadex’s primary mechanism of action is the encapsulation of specific neuromuscular blocking agents, particularly steroidal ones such as rocuronium and vecuronium, through a host of non-covalent interactions. This process effectively reverses neuromuscular blockade by removing the agent from the neuromuscular junction.
What percentage of Sugammadex is typically excreted in the urine within 6 hours of administration?
A) 50%
B) 70%
C) 90%
D) 100%
Answer: B) 70%
Rationale: According to the slide, 70% of Sugammadex is eliminated in the urine within the first 6 hours, highlighting the drug’s rapid clearance via renal excretion.
For patients with renal impairment, Sugammadex clearance is:
A) Enhanced and does not require dialysis.
B) Unaffected, as the drug is not eliminated by the kidneys.
C) Decreased and may require dialysis.
D) Increased due to compensatory hepatic excretion.
Answer: C) Decreased and may require dialysis.
Rationale: The slide indicates that in patients with renal impairment, Sugammadex clearance is decreased (notated as ‘C/I with dialysis’), suggesting that these patients may require dialysis for the removal of the drug due to reduced renal function.
What is the elimination half-life of Sugammadex?
A) 1 hour
B) 2 hours
C) 4 hours
D) 8 hours
Answer: B) 2 hours
Rationale: The slide presents the elimination half-life of Sugammadex as 2 hours, which is the time it takes for half of the drug to be eliminated from the plasma.
After 24 hours, what percentage of Sugammadex is typically eliminated from the body?
A) 50%
B) 70%
C) 90%
D) 100%
Answer: C) 90%
Rationale: The slide shows that within 24 hours, approximately 90% of Sugammadex is excreted in the urine, demonstrating the drug’s efficient renal elimination over a day.
When using a selective relaxant-binding agent for a moderate neuromuscular block, what is the recommended dose if the second twitch (T2) has reappeared in response to train-of-four (TOF) stimulation?
A) 1 mg/kg
B) 2 mg/kg
C) 3 mg/kg
D) 4 mg/kg
Answer: B) 2 mg/kg
Rationale: For a moderate block, where spontaneous recovery has reached the reappearance of the second twitch in TOF stimulation, the recommended dose is 2 mg/kg.
For a deep neuromuscular block, where spontaneous recovery has shown 1-2 post-tetanic counts with no twitch responses to TOF, what dose of the selective relaxant-binding agent is advised?
A) 1 mg/kg
B) 2 mg/kg
C) 3 mg/kg
D) 4 mg/kg
Answer: D) 4 mg/kg
Rationale: In cases of deep block, indicated by 1-2 post-tetanic counts and no twitches upon TOF stimulation, the dose of the selective relaxant-binding agent should be increased to 4 mg/kg.
The dosing of a selective relaxant-binding agent is contingent upon what aspect of neuromuscular blockade?
A) The specific agent used
B) The time since the last dose of relaxant
C) The depth of neuromuscular blockade
D) The preference of the anesthesiologist
Answer: C) The depth of neuromuscular blockade
Rationale: The dose of a selective relaxant-binding agent, as outlined in the slide, depends on the depth of the neuromuscular blockade, assessed by the presence and number of twitches in response to TOF stimulation.
The presence of the second twitch (T2) in a TOF stimulation suggests what depth of blockade and subsequent dosing of the reversal agent?
A) Light block, 1 mg/kg
B) Moderate block, 2 mg/kg
C) Deep block, 2 mg/kg
D) Deep block, 4 mg/kg
Answer: B) Moderate block, 2 mg/kg
Rationale: The slide indicates that if the second twitch (T2) is observed upon TOF stimulation, it is indicative of a moderate block, and the dosing should be 2 mg/kg for the selective relaxant-binding agent.
What is the recommended dose range of Sugammadex for reversing an extreme block?
A) 2 to 4 mg/kg
B) 4 to 8 mg/kg
C) 8 to 16 mg/kg
D) 16 to 32 mg/kg
Answer: C) 8 to 16 mg/kg
Rationale: The slide specifies that for an extreme block, a higher dose range of 8 to 16 mg/kg of Sugammadex is recommended.
Recurarization refers to the return of neuromuscular blockade after initial reversal. According to the information provided, when is recurarization observed with Sugammadex?
A) At any dose
B) At lower than recommended doses
C) At appropriate doses
D) Recurarization is not observed at appropriate doses
Answer: D) Recurarization is not observed at appropriate doses
Rationale: The slide indicates that recurarization is not observed when Sugammadex is used at appropriate doses, suggesting that dosing within the recommended range is critical for a sustained reversal of neuromuscular blockade.
According to the graph, what is the median recovery time to a TOFR of 0.9 after administration of 2 mg/kg Sugammadex?
A) 1.4 minutes
B) 2.15 minutes
C) 12 minutes
D) 17 minutes
Answer: A) 1.4 minutes
Rationale: The graph shows that the median (Q1, Q3) recovery time to a TOFR of 0.9 for Sugammadex is 1.4 minutes, with the first and third quartiles being 1.2 and 1.7 minutes respectively.
What does the cumulative recovery rate indicate in this graph?
A) The proportion of patients who have reached a TOFR of 0.9 at each time point
B) The total number of patients who received Sugammadex or neostigmine
C) The average dose of Sugammadex or neostigmine administered
D) The likelihood of experiencing adverse reactions to Sugammadex or neostigmine
Answer: A) The proportion of patients who have reached a TOFR of 0.9 at each time point
Rationale: The cumulative recovery rate in the graph illustrates the proportion of patients who have reached a TOFR of 0.9 over time after receiving either Sugammadex or neostigmine.
When comparing the recovery times of Sugammadex and neostigmine, which statement is true based on the graph?
A) Recovery times are faster with neostigmine than with Sugammadex.
B) Recovery times for Sugammadex and neostigmine are approximately the same.
C) Recovery times are faster with Sugammadex than with neostigmine.
D) Neostigmine has a more consistent recovery time compared to Sugammadex.
Answer: C) Recovery times are faster with Sugammadex than with neostigmine.
Rationale: The graph demonstrates a steeper curve for Sugammadex, indicating faster recovery times to reach a TOFR of 0.9 compared to the more gradual curve for neostigmine.
Which of the following is a dose-related side effect of Sugammadex?
A) Hyperglycemia
B) Pruritus
C) Hypertension
D) Dizziness
Answer: B) Pruritus
Rationale: According to the first slide, pruritus is listed as a dose-related side effect of Sugammadex.
After reversing rocuronium with Sugammadex, how long should one wait before re-administering rocuronium if additional neuromuscular blockade is needed?
A) Immediately
B) 5 minutes
C) 1 hour
D) 4 hours
Answer: B) 5 minutes
Rationale: The second slide recommends a minimum waiting time of 5 minutes before re-administering rocuronium at a dose of 1.2 mg/kg after reversal with Sugammadex.
