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Action/Kinetics:
Binds to cholinergic receptors on the motor end-plate to block the action of acetylcholine, resulting in a blockade of neuromuscular transmission. Up to 3 times more potent than pancuronium and up to 12 times more potent than metocurine. The time to maximum neuromuscular blockade during balanced anesthesia is dose-dependent and ranges from 9.3 min (following doses of 0.025 mg/kg) to 3.5 min (following doses of 0.08 mg/kg). The time to 25% recovery from blockade following balanced anesthesia ranges from 55 min for doses of 0.025 mg/kg to 160 min for doses of 0.08 mg/kg.
t
1/2, elimination: Dose-dependent, ranging from 86 to 123 min. The half-life is prolonged in kidney transplant clients. Children require higher doses on a mg/kg basis than adults to achieve the same level of blockade. Also, the onset, time, and duration of block are shorter in children than adults. The blockade may be reversed by anticholinesterase agents. Excreted unchanged through the urine and bile.
Uses:
Adjunct to general anesthesia to provide skeletal muscle relaxation during surgery. Skeletal muscle relaxation for ET intubation or to facilitate mechanical ventilation.
Special Concerns:
Use with caution during lactation. Safety and effectiveness have not been determined in children less than 2 years of age. The duration of action may be up to twice as long for clients over 60 years of age and those who are obese (more than 30% more than ideal body weight for height). Malignant hyperthermia may occur in any client receiving a general anesthetic. A profound effect may be noted in clients with neuromuscular diseases such as myasthenia gravis and the myasthenic syndrome.
Side Effects:
Neuromuscular: Skeletal muscle weakness,
profound and prolonged skeletal muscle paralysis causing respiratory insufficiency and apnea; difficulty in reversing the neuromuscular blockade.
CV: Hypotension, flushing,
ventricular fibrillation, MI.
Respiratory: Wheezing,
bronchospasm.
Dermatologic: Urticaria, reaction at injection site.
Miscellaneous: Fever, diplopia.
Overdose Management:
Symptoms: Prolonged neuromuscular block.
Treatment: Maintain a patent airway and use controlled ventilation if necessary until recovery of normal neuromuscular function. Once recovery begins, it can be facilitated by giving neostigmine, 0.06 mg/kg.
Drug Interactions:
-
Aminoglycosides /
Doxacurium effect
-
Bacitracin /
Doxacurium effect
-
Carbamazepine /
Doxacurium onset of effects and
duration of action
-
Clindamycin /
Doxacurium effect
-
Colistin /
Doxacurium effect
-
Enflurane /
Amount of doxacurium necessary to cause blockade and
the duration of action
-
Halothane /
Amount of doxacurium necessary to cause blockade and
the duration of action
-
Isoflurane /
Amount of doxacurium necessary to cause blockade and
the duration of action
-
Lincomycin /
Doxacurium effect
-
Lithium /
Doxacurium effect
-
Local anesthetics /
Doxacurium effect
-
Magnesium salts /
Doxacurium effect
-
Phenytoin /
Doxacurium onset of effects and
duration of action
-
Polymyxins /
Doxacurium effect
-
Procainamide /
Doxacurium effect
-
Quinidine /
Doxacurium effect
-
Sodium colistimethate /
Doxacurium effect
-
Tetracyclines /
Doxacurium effect
How Supplied:
Injection: 1 mg/mL
Dosage
?IV Only
As a component of thiopental/narcotic induction-intubation, to produce neuromuscular blockade of long duration.
Adults, initial: 0.05 mg/kg.
If administered during steady-state enflurane, halothane, or isoflurane anesthesia.
Reduce dose by one-third.
Children: 0.03 mg/kg for blockade lasting about 30 min or 0.05 mg/kg for blockade lasting about 45 min when used during halothane anesthesia. Maintenance doses are required more frequently in children.
Used with succinylcholine to facilitate ET intubation.
Initial: 0.025 mg/kg will provide approximately 60 min of effective blockade.
Maintenance doses: Required about 60 min after an initial dose of 0.025 mg/kg or 100 min after an initial dose of 0.05 mg/kg during balanced anesthesia. Maintenance doses between 0.005-0.01 mg/kg provide an average of 30 min and 45 min, respectively, of additional neuromuscular blockade.
