Classifications: skeletal muscle relaxant, nondepolarizing; neuromuscular blocker;
Therapeutic: skeletal muscle relaxant
; neuromuscular blocker
Pregnancy Category: C


10 mg/mL injection


Inhibits neuromuscular transmission by binding competitively with acetylcholine to muscle end plate receptors. Has no apparent effect on pain threshold, consciousness, or cerebration. Given in general anesthesia only after unconsciousness has been induced by other drugs.

Therapeutic Effect

Synthetic skeletal muscle relaxant that produces short duration of neuromuscular blockade, exhibits minimal direct effects on cardiovascular system, and has less histamine-releasing action.


Adjunct for general anesthesia to produce skeletal muscle relaxation during surgery; to facilitate endotracheal intubation. Especially useful for patients with severe renal or hepatic disease, limited cardiac reserve, and in patients with low or atypical pseudocholinesterase levels.


Myasthenia gravis; pregnancy (category C). Safety during lactation is not established.

Cautious Use

When appreciable histamine release would be hazardous (as in asthma or anaphylactoid reactions, significant cardiovascular disease), neuromuscular disease (e.g., Eaton-Lambert syndrome), carcinomatosis, electrolyte or acid–base imbalances, dehydration, impaired pulmonary function.

Route & Dosage

Skeletal Muscle Relaxation
Adult/Child (≥2 y): IV 0.4–0.5 mg/kg initial dose, then 0.08–0.1 mg/kg bolus 20–45 min after the first dose and q15–25 min thereafter; reduce doses if used with general anesthetics
Child (1 mo–2 y): IV 0.3–0.4 mg/kg

Mechanical Ventilation
Adult: IV 5–9 mcg/kg/min by continuous infusion


  • Verify correct concentration and rate of infusion for infants and children with physician.

PREPARE: Direct: Give initial bolus dose undiluted.  Continuous: Maintenance dose must be diluted with NS, D5W or D5/NS. Maximum concentration should be 0.5 mg/mL. Do not mix in same syringe or administer through same needle as used for alkaline solutions [incompatible with alkaline solutions (e.g., barbiturates)].  

ADMINISTER: Direct: Give as bolus dose over 30–60 sec.  Continuous: Give infusion at rate required to maintain desired effect.  

INCOMPATIBILITIES Solution/additive: Ringer's lactate, aminophylline, cefazolin, heparin, quinidine, ranitidine, sodium nitroprusside. Y-site: Diazepam, propofol, thiopental.

  • Store at 2°–8° C (36°–46° F) to preserve potency unless otherwise directed. Avoid freezing.

Adverse Effects (≥1%)

CV: Bradycardia, tachycardia. Respiratory: Respiratory depression. Other: Increased salivation, anaphylaxis.


Drug: general anesthetics increase magnitude and duration of neuromuscular blocking action; aminoglycosides, bacitracin, polymyxin B, clindamycin, lidocaine, parenteral magnesium, quinidine, quinine, trimethaphan, verapamil increase neuromuscular blockade; diuretics may increase or decrease neuromuscular blockade; lithium prolongs duration of neuromuscular blockade; narcotic analgesics present possibility of additive respiratory depression; succinylcholine increases onset and depth of neuromuscular blockade; phenytoin may cause resistance to or reversal of neuromuscular blockade.


Onset: 2 min. Peak: 3–5 min. Duration: 60–70 min. Distribution: Well distributed to tissues and extracellular fluids; crosses placenta; distribution into breast milk unknown. Metabolism: Rapid nonenzymatic degradation in bloodstream. Elimination: 70–90% in urine in 5–7 h. Half-Life: 20 min.

Nursing Implications

Assessment & Drug Effects

  • Lab tests: Baseline serum electrolytes, acid–base balance, and renal function as part of preanesthetic assessment.
  • Note: Personnel and equipment required for endotracheal intubation, administration of oxygen under positive pressure, artificial respiration, and assisted or controlled ventilation must be immediately available.
  • Evaluate degree of neuromuscular blockade and muscle paralysis to avoid risk of overdosage by qualified individual using peripheral nerve stimulator.
  • Monitor BP, pulse, and respirations and evaluate patient's recovery from neuromuscular blocking (curare-like) effect as evidenced by ability to breathe naturally or to take deep breaths and cough, keep eyes open, lift head keeping mouth closed, adequacy of hand-grip strength. Notify physician if recovery is delayed.
  • Note: Recovery from neuromuscular blockade usually begins 35–45 min after drug administration and is almost complete in about 1 h. Recovery time may be delayed in patients with cardiovascular disease, edematous states, and in older adults.

Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; Canadian drug name; Prototype drug

© 2006-2022 Last Updated On: 10/02/2022 (0)
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