Mivacron

Mivacron - General Information

Mivacron is a bisbenzylisoquinolinium based neuromuscular blocker or muscle relaxant. It binds competitively to cholinergic receptors on the motor end-plate to antagonize the action of acetylcholine, resulting in a block of neuromuscular transmission.

Pharmacology of Mivacron

Mivacron is a short-acting, nondepolarizing skeletal neuromuscular blocking agent which is hydrolyzed by plasma cholinesterase. Mivacron 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.

Mivacron for patients

Before you are given it tell your doctor if:

• You have a history of asthma, hayfever or allergies
• You have recently lost a lot of fluids, e.g. been vomiting, diarrhoea (frequent watery faeces/poos), sweating excessively, been doing high levels of exercise, or lost a lot of blood.
• You may have salt imbalances e.g. you have been drinking excessive quantities of water or have been taking large amounts of salts, or have had diarrhoea or have a bowel problem or no large bowel
• You have myasthenia gravis
• You have any other disease of nerves and muscles (neuromuscular disease)
• You have heart disease
• You have severe kidney disease e.g. kidney failure
• You have liver disease
• You are pregnant or breastfeeding.
• Your doctor will discuss with you the risks and benefits of using Mivacron while you are pregnant or breastfeeding.

Tell your doctor if you are taking any other medicines, including medicines that you buy without a prescription from your pharmacy, supermarket or health food shop. Some medicines may interfere with Mivacron. These include:

• Antibiotics, including doxycycline (Doxine^TM, Doxy tabs^TM), minocycline (Mino-tabs^TM, Minomycin^TM), clindamycin (Dalacin^TM).
• Medicines for irregular heart beats including propranolol (Cardinol), calcium channel blockers, e.g. diltiazem (Dilzem^TM, Cardizem^TM), felodipine (Felo^TM, Plendil^TM), nifedipine (Adalat^TM, Nyefax^TM), amlodipine (Norvasc^TM), verapamil (Verpamil^TM, Isoptin^TM), lignocaine (Xylocard^TM), procainamide and quinidine.
• Water tablets (diuretics), e.g. frusemide (Diurin^TM, Frusid^TM, Lasix^TM), bendrofluazide (Neo-naclex^TM), chlorothiazide, chlorthalidone (Hygroton^TM), cyclopenthiazide (Navidrex^TM), indapamide (Napamide^TM, Naplin^TM), mannitol, acetazolamide (Diamox^TM).
• Magnesium or calcium salts
• Ketamine
• Lithium (Lithicarb^TM, Priadel^TM)
• A type of antidepressant called a monoamine oxidase inhibitor (MAOI) e.g. tranylcypromine (Parnate^TM)
• Bambuterol (Bambec^TM)

Mivacron Interactions

Although MIVACRON (a mixture of three stereoisomers) has been administered safely following succinylcholine-facilitated tracheal intubation, the interaction between MIVACRON and succinylcholine has not been systematically studied. Prior administration of succinylcholine can potentiate the neuromuscular blocking effects of nondepolarizing agents. Evidence of spontaneous recovery from succinylcholine should be observed before the administration of MIVACRON.

The use of MIVACRON before succinylcholine to attenuate some of the side effects of succinylcholine has not been studied.

There are no clinical data on the use of MIVACRON with other nondepolarizing neuromuscular blocking agents.

Isoflurane and enflurane (administered with nitrous oxide/oxygen to achieve 1.25 M.C. decrease the ED₅₀ of MIVACRON by as much as 25% (see CLINICAL PHARMACOLOGY: Pharmacodynamics and Individualization of Dosages). These agents may also prolong the clinically effective duration of action and decrease the average infusion requirement of MIVACRON by as much as 35% to 40%. A greater potentiation of the neuromuscular blocking effects of MIVACRON may be expected with higher concentrations of enflurane or isoflurane. Halothane has little or no effect on the ED₅₀, but may prolong the duration of action and decrease the average infusion requirement by as much as 20%.

Other drugs which may enhance the neuromuscular blocking action of nondepolarizing agents such as MIVACRON include certain antibiotics (e.g., aminoglycosides, tetracyclines, bacitracin, polymyxins, lincomycin, clindamycin, colistin, and sodium colistimethate), magnesium salts, lithium, local anesthetics, procainamide, and quinidine. The neuromuscular blocking effect of MIVACRON may be enhanced by drugs that reduce plasma cholinesterase activity (e.g., chronically administered oral contraceptives, glucocorticoids, or certain monoamine oxidase inhibitors) or by drugs that irreversibly inhibit plasma cholinesterase.

Resistance to the neuromuscular blocking action of nondepolarizing neuromuscular blocking agents has been demonstrated in patients chronically administered phenytoin or carbamazepine. While the effects of chronic phenytoin or carbamazepine therapy on the action of MIVACRON are unknown, slightly shorter durations of neuromuscular block may be anticipated and infusion rate requirements may be higher.

Some drug interactions are:

• birth control pills
• corticosteroids
• medicines for angina or high blood pressure
• medicines for pain
• medicines to control seizures such as phenytoin or carbamazepine
• certain antibiotics given by injection
• cisplatin
• edrophonium
• neostigmine
• polymyxin B or bacitracin
• local anesthetics such as procaine
• general anesthetics
• succinylcholine or other muscle relaxants

Mivacron Contraindications

MIVACRON is contraindicated in patients known to have an allergic hypersensitivity to mivacurium chloride or other benzylisoquinolinium agents, as manifested by reactions such as urticaria or severe respiratory distress or hypotension. Use of MIVACRON from multiple-dose vials containing benzyl alcohol as a preservative is contraindicated in patients with a known hypersensitivity to benzyl alcohol.

Multiple-dose vials of Mivacron contain benzyl alcohol, while single-dose vials do not. Use from multiple-dose vials is contraindicated in patients with a known hypersensitivity to benzyl alcohol.

In newborn infants (children less than 1 month in age), benzyl alcohol has been associated with an increased incidence of neurological and other complications which are sometimes fatal. I.V. preparations containing benzyl alcohol should not be used in newborns.

Additional information about Mivacron

Mivacron 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.
Mechanism Of Action: Mivacron 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.
Drug Interactions: Not Available
Food Interactions: Not Available
Generic Name: Mivacurium
Synonyms: Not Available
Drug Category: Neuromuscular Nondepolarizing Agents
Drug Type: Small Molecule; Approved

Other Brand Names containing Mivacurium: Mivacron;
Absorption: Not Available
Toxicity (Overdose): Overdosage with neuromuscular blocking agents may result in neuromuscular block beyond the time needed for surgery and anesthesia.
Protein Binding: The protein binding of mivacurium has not been determined due to its rapid hydrolysis by plasma cholinesterase.
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.
Dosage Forms of Mivacron: Liquid Intravenous
Chemical IUPAC Name: bis[3-[(1R)-6,7-dimethoxy-2-methyl-1-[(3,4,5-trimethoxyphenyl)methyl]-3,4-dihydro-1H-isoquinolin-2-ium-2-yl]propyl] (E)-oct-4-enedioate
Chemical Formula: C58H80N2O14+2
Mivacurium on Wikipedia: https://en.wikipedia.org/wiki/Mivacurium
Organisms Affected: Humans and other mammals