Cisatracurium

Cisatracurium

Trade names	Nimbex
Clinical data
Drug class	Neuromuscular blocker
Uses	Tracheal intubation, surgical relaxation, optimizing mechanical ventilation, patients with ARDS
Contraindications	Known hypersensitivity
Routes of administration	IV
Dosage
Pharmacodynamics
Mechanism of action	Nicotinic acetylcholine antagonism
Adverse effects	Anaphylactic reaction Histamine release
Pharmacokinetics
Onset of action	3 to 5 minutes
Duration of action	45 minutes
Metabolism	Hofmann Elimination
Physical and chemical data
Article quality
Editor rating	Comprehensive
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Cisatracurium is a benzylisoquinolinium intermediate acting nondepolarizing neuromuscular blocking agent used for tracheal intubation and surgical relaxation. Unlike agents such as rocuronium or vecuronium, cisatracurium is metabolized via Hofmann elimination, making it a safer choice for patients with severe renal or hepatic dysfunction. However, due to its longer onset of action, it is rarely used outside this population, and is not considered appropriate for use in a rapid sequence induction. It is also used as an infusion to provide paralysis in intubated patients with acute respiratory distress syndrome in the intensive care unit.

Uses

• Muscle relaxation for intubation
  • Primarily used in patients with severe renal and/or hepatic dysfunction
  • Not appropriate for RSI due to longer onset of action
• Maintenance of surgical relaxation

• Paralysis in patients with acute respiratory distress syndrome in the intensive care unit via continuous infusion
  • Used early in the course of ARDS for patients with a PaO2/FiO2 less than 150
  • The proposed mechanism of the beneficial effect is possibly by lowering transpulmonary pressure reducing barotrauma

Contraindications

Absolute contraindications

• Known hypersensitivity

Precautions

• Patients with myasthenia gravis/myathenic syndrome
• Amyotrophic lateral sclerosis
• Autoimmune disorders including polymyositis, dermatomyositis and systemic lupus erythematous
• Familial periodic paralysis hyperkalemia
• Guillain-Barré syndrome
• Muscular dystrophy (Duchenne type)
• Myotonia including dystrophic, congenital,, and paramyotonia
• Patients who may have resistance include:
  • Burn injury
  • Cerebral palsy
  • Hemiplegia (on the affected side)
  • Muscular denervation
  • Severe chronic infection such as tetanus and botulism

Pharmacology

Pharmacodynamics

• Roughly about 3 times the potency of atracurium

Mechanism of action

• Competitive antagonism of acetylcholine at the post junctional receptors preventing depolarization of the muscle preventing any movement. Only one molecule of the neuromuscular blocker is needed to prevent activation of the receptor as it competes with acetylcholine at the two binding sites.

Adverse effects

• Anaphylactic reaction
• Histamine release leading to hypotension, bronchospasm, rash
• Bradycardia

• Muscle weakness or myopathy due to persistent failure of neuromuscular transmission and immobilization-induced atrophy of diaphragm
• Posttraummatic stress syndrome from awareness during paralysis if sedation is not used adequately.
• Impairment of ventilation-perfusion distribution and decreased right ventricular end-diastolic volume due to abolishment of spontaneous breathing.
• Incomplete reversal of neuromuscular blocking agent leading to respiratory depression

Pharmacokinetics

• Eliminated via Hofmann elimination
• Duration of action after 2 x ED₉₅ is 45 minutes
• With prolonged infusion, elimination half life is 20 minutes

Chemistry and formulation

1 R-cis 1'R-cis stereoisomer of the 10 stereoisomers that comprise atracurium

History

The development involved isolation and testing of individual stereoisomers from the mixture found in atracurium