Atracurium and cisatracurium two different types of nondepolarizing neuromuscular blocking agents. Neuromuscular blocking agents (NMBAs) come in two forms: depolarizing neuromuscular blocking agents such as succinylcholine and nondepolarizing neuromuscular blocking agents such as rocuronium, vecuronium, atracurium, cisatracurium, and mivacurium.
The key difference between atracurium and cisatracurium is their potency. Atracurium is comparatively a less potent nondepolarizing neuromuscular blocking agent while cisatracurium is comparatively a more potent nondepolarizing neuromuscular blocking agent.
CONTENTS
1. Overview and Key Difference
2. What is Atracurium
3. What is Cisatracurium
4. Similarities – Atracurium and Cisatracurium
5. Atracurium vs Cisatracurium in Tabular Form
6. Summary – Atracurium vs Cisatracurium
7. FAQ – Atracurium and Cisatracurium
What is Atracurium?
Atracurium is a nondepolarizing neuromuscular blocker. It is used to facilitate endotracheal intubation and relaxation of skeletal muscles during surgery. Atracurium has a short duration of action. Moreover, atracurium lacks any significant cardiovascular effects.
Furthermore, the fact that atracurium does not rely on good kidney function for elimination gives it a clinical advantage over other nondepolarizing neuromuscular blocking agents. However, there are some side effects of atracurium, such as tachycardia (rapid heartbeat), temporary hypotension (low blood pressure), wheezing, bronchospasm (asthma-like symptoms), skin flushing, and urticaria (nettle rash).
What is Cisatracurium?
Cisatracurium is a non-depolarising neuromuscular blocking agent of the benzylisoquinolinium class. Cisatracurium has an intermediate or long duration of action, and it is one of the most commonly used neuromuscular blocking agents in intensive care. Cisatracurium is also known as a skeletal muscle relaxant used to facilitate tracheal intubation and muscle relaxation in surgery.
Cisatracurium is an R-cis-R-cis isomer of atracurium non-depolarising neuromuscular blocking agent. Therefore, it has approximately 3 times neuromuscular blocking potency compared to atracurium. Furthermore, cisatracurium produces a lower degree of histamine release compared to atracurium. The side effects of cisatracurium are blurred vision, chest pain or discomfort, confusion, difficulty breathing, dizziness, faintness, or lightheadedness when one gets up suddenly from a lying or sitting position, sweating, and slow or irregular heartbeat.
Similarities Between Atracurium and Cisatracurium
- Atracurium and cisatracurium are two non-depolarising neuromuscular blocking agents.
- Cisatracurium is an R-cis-R-cis isomer of atracurium.
- Both belong to the benzylisoquinoline class.
- They are injected into the body.
- Both are used as muscle relaxants and in surgeries.
- Both have potential side effects.
Difference Between Atracurium and Cisatracurium
Definition
- Atracurium is a less potent, non-depolarising neuromuscular blocking agent in the benzylisoquinolinium class.
- Cisatracurium is a more potent, non-depolarising neuromuscular blocking agent in the benzylisoquinolinium class.
Duration of Action
- Atracurium has a short duration of action.
- Cisatracurium has an intermediate or long duration of action.
Histamine Release
- Atracurium produces a higher degree of histamine release compared to atracurium.
- Cisatracurium produces a lower degree of histamine release compared to atracurium.
Cardiovascular Effects
- A small increase (5-8%) in heart rate was observed after administering atracurium at doses of 0.5-0.6 mg/kg.
- Cisatracurium has no clinically significant cardiovascular effects at doses of up to 0.4mg/kg in healthy adults.
Side Effects
- Side effects of atracurium are tachycardia, temporary hypotension, wheezing, bronchospasm, skin flushing, and urticaria.
- Side effects of cisatracurium are blurred vision, chest pain or discomfort, confusion, difficulty breathing, dizziness, faintness, or lightheadedness when one gets up suddenly from a lying or sitting position, sweating, slow or irregular heartbeat, tightness in chest and unusual tiredness or weakness.
The following table summarizes the difference between atracurium and cisatracurium.
Summary – Atracurium vs Cisatracurium
Nondepolarizing neuromuscular blockers are competitive acetylcholine (ACh) antagonists. They bind directly to nicotinic receptors on the postsynaptic membrane. This action blocks the activation of the motor endplate, resulting in muscle paralysis. Atracurium and cisatracurium are two non-depolarising neuromuscular blocking agents. However, atracurium is a less potent non-depolarising neuromuscular blocking agent in benzylisoquinolinium class with a short duration of action, while cisatracurium is a more potent non-depolarising neuromuscular blocking agent in benzylisoquinolinium class with an intermediate or long duration action. This summarizes the difference between atracurium and cisatracurium.
FAQ: Atracurium and Cisatracurium
1. What are the examples of nondepolarizing neuromuscular blocking agents?
- Nondepolarizing neuromuscular blockers are acetylcholine antagonists. Some examples of nondepolarizing neuromuscular blocking agents are rocuronium, vecuronium, atracurium, cisatracurium, and mivacurium.
2. What is the use of atracurium?
- Atracurium is a medication that provides skeletal muscle relaxation during surgery or mechanical ventilation. Moreover, it can help with endotracheal intubation but takes up to 2.5 minutes to result in appropriate intubating conditions.
3. What are the cardiac effects of atracurium?
- Recent research has found that atracurium causes a small increase (5-8%) in heart rate after doses of atracurium 0.5-0.6 mg/kg. In severe cases, atracurium trigger bradycardia in patients.
4. Is cisatracurium a paralytic?
- Yes. Cisatracurium is a neuromuscular blocker or muscle paralytic drug. It is a nondepolarizing neuromuscular blocker in the same benzylisoquinolinium class as pancuronium, vecuronium, and atracurium.
5. Why is cisatracurium used in the ICU?
- Cisatracurium is used to provide skeletal muscle relaxation to facilitate mechanical ventilation in an ICU (intensive care unit) setting. However, it must be used with sedation.
Reference:
1. “Atracurium Besylate Injection, USP Warnings and Precautions.” Pfizer Medical Information.
2. “Cisatracurium – An Overview.” ScienceDirect.
Image Courtesy:
1. “Neuromuscularnondepolarizingagent” By Madhero88 – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Cisatracurium Besylate” By D-tubocurarine at English Wikipedia (CC BY-SA 3.0) via Commons Wikimedia
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