OB-GYN 101
Pharmacy

Category:

• Muscle relaxant

  Description:

• Depolarizing neuromuscular blocking agent

  Indications:

• Adjunct to general anesthesia to facilitate intubation and skeletal muscle relaxation

  Contraindications:

• Patients with genetically determined disorders of plasma pseudocholinesterase

• Personal or family history of malignant hyperthermia

• Myopathies associated with elevated creatine phosphokinase values

• Acute narrow-angle glaucoma

• Penetrating eye injuries

Precautions:

• Pregnancy category C

• Only used by skilled personnel in airway management and respiratory support.

• Must have anticholinesterase reversal agents immediately available during use.

• Use with caution in patients with cardiovascular, hepatic, pulmonary, metabolic or renal dysfunction.

• Use with caution in patients with severe burns and electrolyte imbalances.

• Prolonged blockade may occur in patients who are hypokalemic, hypocalcemic, or having hepatic, cardiovascular or pulmonary disorders.

• Produces a slight, transient increase in intraocular and intracranial pressure.

• May cause malignant hyperthermia in susceptible patients.

• Will cause histamine release.  Use with caution in patients susceptible to histamine, such as cardiovascular disease and asthma.

• Contains benzyl alcohol that may cause “gasping syndrome” in premature infants.

• May cause bradycardia during anesthesia.

• Use with caution in patients with neuromuscular disease.

• Use a peripheral nerve stimulator to monitor twitch suppression and recovery.

  Adverse Reactions (Side Effects):

• Cardiovascular: hypotension, vasodilation, tachycardia, bradycardia, cardiac arrest

• Respiratory depression and apnea

• Malignant hyperthermia, increased intraocular pressure, muscle twitching, post-operative muscle pain

• Excessive salivation

· Administered via IV or IM injection

· Initiate therapy only after patient is unconscious.

· Short surgery: 0.6mg/kg IV (paralysis lasts 2 minutes, recovery 4-6 minutes)

· Long surgery: 2.5-4.3mg/min (commonly 1-2mg/mL infused as constant IV drip)

· Prolonged relaxation (mechanical ventilation): 0.3-1.1mg/kg initial, then 0.04-0.07mg/kg administered to maintain relaxation as IV infusion

· Children:

  - young children: 2mg/kg IV

  - older children: 1mg/kg IV

  - IM (in absence of suitable vein): 3-4mg/kg (not to exceed 150mg)