indication

For inpatients and outpatients, as an adjunct to general anesthesia, to facilitate tracheal intubation and to provide skeletal muscle relaxation during surgery or mechanical ventilation.

pharmacology

Mivacurium is a short-acting, nondepolarizing skeletal neuromuscular blocking agent which is hydrolyzed by plasma cholinesterase. Mivacurium results in a blockade of neuromuscular transmission by binding competitively with cholinergic receptors on the motor end-plate to antagonize the action of acetylcholine. The neuromuscular block produced by mivacurium is readily antagonized by anticholinesterase agents. The deeper the level of neuromuscular block at reversal, the longer the time required for recovery of neuromuscular function and the greater the dose of anticholinesterase agent required. Because spontaneous recovery after mivacurium is rapid, routine reversal may not always result in a clinical benefit.

mechanism of action

Mivacurium binds competitively to cholinergic receptors on the motor end-plate to antagonize the action of acetylcholine, resulting in a block of neuromuscular transmission. This action is antagonized by acetylcholinesterase inhibitors, such as neostigmine.

toxicity

Overdosage with neuromuscular blocking agents may result in neuromuscular block beyond the time needed for surgery and anesthesia.

biotransformation

Extensive and rapid via enzymatic hydrolysis catalyzed by plasma cholinesterase. Biotransformation may be significantly slowed in patients with abnormal or decreased plasma cholinesterase activity, especially individuals with a homozygous atypical cholinesterase gene abnormality.

half life

The mean elimination half-life ranges from 1.7 to 2.6 minutes in healthy, young adults administered 0.1 to 0.25 mg/kg mivacurium. In 9 patients with end-stage liver disease undergoing liver transplant surgery, plasma clearance was approximately 50% lower than that in 8 control patients with normal hepatic function, while the elimination half-life increased to 4.4 minutes from the 1.8 minute control value.

drug interactions

Amikacin: The agent increases the effect of muscle relaxant

Aminophylline: Theophylline decreases the effect of muscle relaxant

Azathioprine: The agent decreases the effect of the muscle relaxant

Carbamazepine: Decrease the effect of muscle relaxant

Clindamycin: The agent increases the effect of muscle relaxant

Fosphenytoin: Phenytoin decreases the effect of muscle relaxant

Gentamicin: The agent increases the effect of muscle relaxant

Lincomycin: The agent increases the effect of muscle relaxant

Mercaptopurine: The agent dereases the effect of the muscle relaxant

Netilmicin: The agent increases the effect of muscle relaxant

Oxtriphylline: Theophylline decreases the effect of muscle relaxant

Phenytoin: Phenytoin decreases the effect of the muscle relaxant

Piperacillin: The agent increases the effect of the muscle relaxant

Theophylline: Theophylline decreases the effect of the muscle relaxant

Tobramycin: The agent increases the effect of the muscle relaxant