INFORMATION FOR HEALTH PROFESSIONALS
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MIVACRON injection is a clear, pale yellow, sterile aqueous solution in glass ampoules containing 2mg/mL mivacurium, present as mivacurium chloride. Each 5mL ampoule contains 10mg mivacurium and each 10mL ampoule contains 20mg mivacurium.
Injection solution.
MIVACRON is a highly selective, short-acting, non-depolarising neuromuscular blocking agent with a fast recovery profile. MIVACRON is used as an adjunct to general anaesthesia to relax skeletal muscles and to facilitate tracheal intubation and mechanical ventilation.
This formulation contains no antimicrobial preservative and is intended for single patient use.
MIVACRON is administered by intravenous injection. The mean dose required to produce 95% suppression of the adductor pollicis single twitch response to ulnar nerve stimulation (ED95) is 0.07mg/kg (range 0.06 to 0.09) in adults receiving narcotic anaesthesia.
The following dose regimens are recommended for tracheal intubation
The recommended bolus dose range for healthy adults is 0.07 to 0.25mg/kg. The duration of neuromuscular block is related to the dose. Doses of 0.07, 0.15, 0.20 and 0.25mg/kg produce clinically effective block for approximately 13, 16, 20 and 23 minutes, respectively. Doses of up to 0.15mg/kg may be administered over 5 to 15 seconds. Higher doses should be administered over 30 seconds in order to minimise the possibility of occurrence of cardiovascular effects.
Full block can be prolonged with maintenance doses of MIVACRON. Doses of 0.1mg/kg administered during narcotic anaesthesia each provide approximately 15 minutes of additional clinically effective block.
Successive supplementary doses do not give rise to accumulation of neuromuscular blocking effect.
The neuromuscular blocking action of mivacurium is potentiated by isoflurane or enflurane anaesthesia. If steady-state anaesthesia with isoflurane or enflurane has been established, the recommended initial MIVACRON dose should be reduced by up to 25%. Halothane appears to have only a minimal potentiating effect on mivacurium and dose reduction of MIVACRON is probably not necessary.
Once spontaneous recovery is underway it is complete in approximately 15 minutes and is independent of the dose administered.
The neuromuscular block produced by mivacurium can be reversed with standard doses of anticholinesterase agents. However, because spontaneous recovery after mivacurium is rapid, reversal may not be routinely required since it shortens recovery time by only 5 to 6 minutes.
Continuous infusion of MIVACRON may be used to maintain neuromuscular block. Upon early evidence of spontaneous recovery from an initial MIVACRON dose, an infusion rate of 8 to 10mcg/kg/min (0.5 to 0.6mg/kg/hr) is recommended.
The initial infusion rate should be adjusted according to the patient's response to peripheral nerve stimulation and clinical criteria.
Adjustments of the infusion rate should be made in increments of approximately 1mcg/kg/min (0.06mg/kg/hr). In general a given rate should be maintained for at least 3 minutes before a rate change is made.
On average, an infusion rate of 6 to 7mcg/kg/min will maintain neuromuscular block within the range of 89% to 99% for extended periods in adults receiving narcotic anaesthesia. During steady-state isoflurane or enflurane anaesthesia, reduction in the infusion rate by up to 40% should be considered. A study has shown that mivacurium infusion rate requirement should be reduced by up to 50% with sevoflurane. With halothane, smaller reductions in infusion rate may be required.
Spontaneous recovery after infusion of MIVACRON is independent of the duration of infusion and comparable to recovery reported for single doses.
Continuous infusion of MIVACRON has not been associated with the development of tachyphylaxis or cumulative neuromuscular blockade.
MIVACRON Injection (2mg/mL) may be used undiluted for infusion.
MIVACRON Injection is compatible with the following infusion fluids
When diluted with the listed infusion solutions in the proportion of 1 plus 3 (i.e. to give 0.5mg/mL) MIVACRON Injection has been shown to be chemically and physically stable for at least 48 hours at 30°C. However, since the product contains no antimicrobial preservative dilution should be carried out immediately prior to use, administration should commence as soon as possible thereafter and any remaining solution should be discarded.
MIVACRON has a higher ED95 (approximately 0.1mg/kg), faster onset, shorter clinically effective duration of action and more rapid spontaneous recovery in infants and children aged 7 months to 12 years, than in adults.
The recommended bolus dose range for infants and children aged 7 months to 12 years is 0.1 to 0.2mg/kg administered over 5 to 15 seconds. When administered during stable narcotic or halothane anaesthesia a dose of 0.2mg/kg produces clinically effective block for an average of 9 minutes.
A MIVACRON dose of 0.2mg/kg is recommended for tracheal intubation in infants and children aged 7 months to 12 years. Maximum block is usually achieved within 2 minutes following administration of this dose and intubation should be possible within this time.
Maintenance doses are generally required more frequently in infants and children than in adults. Available data suggest that a maintenance dose of 0.1mg/kg will give approximately 6 to 9 minutes of additional clinically effective block during narcotic or halothane anaesthesia.
Infants and children generally require higher infusion rates than adults . During halothane anaesthesia, the mean infusion rate required to maintain 89 to 99% neuromuscular block in patients aged 7 to 23 months is approximately 11mcg/kg/min (approximately 0.7mg/kg/hr) [range 3 to 26mcg/kg/min (approximately 0.2 to 1.6mg/kg/hr)].
For children aged 2 to 12 years the equivalent mean infusion rate is approximately 13 to 14mcg/kg/min (approximately 0.8mg/kg/hr) [range 5 to 31mcg/kg/min (approximately 0.3 to 1.9mg/kg/hr)] under halothane or narcotic anaesthesia.
The neuromuscular blocking action of mivacurium is potentiated by inhalational agents. A study has shown that mivacurium infusion rate requirement should be reduced by up to 70% with sevoflurane in children aged 2-12 years.
Once spontaneous recovery is underway, it is complete in approximately 10 minutes.
MIVACRON has a similar ED95 to that in adults (0.07mg/kg), but a faster onset, shorter clinically effective duration and more rapid spontaneous recovery in infants aged 2 to 6 months than in adults.
The recommended bolus dose range for infants aged 2 to 6 months is 0.1 to 0.15mg/kg administered over 5 to 15 seconds. When administered during stable halothane anaesthesia a dose of 0.15mg/kg produces clinically effective block for an average of 9 minutes.
A MIVACRON dose of 0.15mg/kg is recommended for tracheal intubation in infants aged 2 to 6 months. Maximum block is achieved approximately 1.4 minutes following administration of this dose and intubation should be possible within this time.
Maintenance doses are generally required more frequently in infants aged 2 to 6 months than in adults. Available data suggest that a maintenance dose of 0.1mg/kg will give approximately 7 minutes of additional clinically effective block during halothane anaesthesia.
Infants aged 2 to 6 months generally require higher infusion rates than adults. During halothane anaesthesia the mean infusion rate required to maintain 89 to 99% neuromuscular block is approximately 11mcg/kg/min (approximately 0.7mg/kg/hr) [range 4 to 24mcg/kg/min (approximately 0.2 to 1.5mg/kg/hr)].
Once spontaneous recovery is underway, it is complete in approximately 10 minutes.
No dose recommendations for neonates and infants under 2 months of age can be made until further information becomes available.
In elderly patients receiving single bolus doses of MIVACRON, the onset time, duration of action and recovery rate may be extended relative to younger patients by 20 to 30%. Elderly patients may also require decreased infusion rates or smaller or less frequent maintenance bolus doses.
In patients with clinically significant cardiovascular disease, the initial dose of MIVACRON should be administered over 60 seconds.
MIVACRON has been administered in this way with minimal haemodynamic effects to patients undergoing cardiac surgery.
In patients with end-stage renal failure the clinically effective duration of block produced by 0.15mg/kg MIVACRON is approximately 1.5 times longer than in patients with normal renal function. Subsequently, dosage should be adjusted according to individual clinical response.
In patients with end-stage hepatic failure the clinically effective duration of block produced by 0.15mg/kg MIVACRON is approximately three times longer than in patients with normal hepatic function. This prolongation is related to the markedly reduced plasma cholinesterase activity seen in these patients.
Subsequently, dosage should be adjusted according to individual clinical response.
Prolonged and intensified neuromuscular blockade may also occur in patients with acute or chronic renal failure as a result of reduced levels of plasma cholinesterase (see Warnings and Precautions).
Mivacurium is metabolized by plasma cholinesterase. Plasma cholinesterase activity may be diminished in the presence of genetic abnormalities of plasma cholinesterase (e.g. patients heterozygous or homozygous for the atypical plasma cholinesterase gene), and in various pathologic conditions (see Warnings and Precautions) and by administration of certain drugs (see Interaction with Other Medicaments and Other Forms of Interaction). The possibility of prolonged neuromuscular block following administration of MIVACRON must be considered in patients with reduced plasma cholinesterase activity. Mild reductions (i.e. within 20% of the lower limit of the normal range) are not associated with clinically significant effects on duration. (See Warnings and Precautions and Precautions for information about homozygous and heterozygous patients)
In obese patients (those weighing 30% or more above their ideal bodyweight for height), the initial dose of MIVACRON should be based upon ideal bodyweight and not actual bodyweight.
IN COMMON WITH ALL NEUROMUSCULAR BLOCKING AGENTS, MONITORING OF NEUROMUSCULAR FUNCTION IS RECOMMENDED DURING THE USE OF MIVACRON IN ORDER TO INDIVIDUALISE DOSAGE REQUIREMENTS.
With MIVACRON, significant train-of-four fade is not seen during onset. It is often possible to intubate the trachea before complete abolition of the train-of-four response of the adductor pollicis muscle has occurred.
MIVACRON should not be administered to patients known to have a hypersensitivity to mivacurium.
MIVACRON is contra-indicated in patients known to be homozygous for the atypical plasma cholinesterase gene (See Special Warnings and Special Precautions for Use).
IN COMMON WITH ALL THE OTHER NEUROMUSCULAR BLOCKING AGENTS, MIVACRON PARALYSES THE RESPIRATORY MUSCLES AS WELL AS OTHER SKELETAL MUSCLES BUT HAS NO EFFECT ON CONSCIOUSNESS. MIVACRON SHOULD BE ADMINISTERED ONLY BY OR UNDER THE CLOSE SUPERVISION OF AN EXPERIENCED ANAESTHETIST WITH ADEQUATE FACILITIES FOR ENDOTRACHEAL INTUBATION AND ARTIFICIAL VENTILATION.
Prolonged and intensified neuromuscular blockade following mivacurium may occur secondary to reduced plasma cholinesterase activity in the following states or pathological conditions:
Iatrogenic: following plasma exchange, plasmapheresis, cardiopulmonary bypass, and as a result of concomitant drug therapy (see Interactions).
In common with suxamethonium/succinylcholine, patients homozygous for the atypical plasma cholinesterase gene (1 in 2500 patients) are extremely sensitive to the neuromuscular blocking effect of mivacurium. In three such adult patients, a small dose of MIVACRON 0.03mg/kg (approximately the ED10-20 in genotypically normal patients), produced complete neuromuscular block for 26 to 128 minutes.
In patients heterozygous for the atypical plasma cholinesterase gene, the clinically effective duration of block of mivacurium 0.15 mg/kg is approximately 10 min longer than in control patients.
Once spontaneous recovery had begun, neuromuscular block in these patients was antagonized with conventional doses of neostigmine.
Patients with burns may develop resistance to non-depolarising neuromuscular blocking agents and require increased doses. However, such patients may also have reduced plasma cholinesterase activity, requiring dose reduction. Consequently, burn patients should be given a test dose of 0.015 to 0.020 mg/kg mivacurium followed by appropriate dosing guided by monitoring of block with a nerve stimulator.
Caution should be exercised in administering MIVACRON to patients with a history suggestive of an increased sensitivity to the effects of histamine e.g. asthma. If MIVACRON is used in this group of patients it should be administered over 60 seconds.
Caution should also be exercised when administering mivacurium to patients who have shown hypersensitivity to other neuromuscular blocking agents since a high rate of cross-sensitivity (greater than 50%) between neuromuscular blocking agents has been reported.
MIVACRON should be administered over a period of 60 seconds to patients who may be unusually sensitive to falls in arterial blood pressure, for example those who are hypovolaemic.
In adults, doses of MIVACRON of greater than or equal to 0.2mg/kg (greater than or equal to 3x ED95) have been associated with histamine release when administered by rapid bolus injection. However, the slower administration of the 0.2mg/kg MIVACRON dose and the divided administration of the 0.25mg/kg MIVACRON dose (see Posology and Method of Administration) minimise the cardiovascular effects of these doses. Cardiovascular safety did not appear to be compromised in children given a rapid bolus dose of 0.2mg/kg in clinical studies.
MIVACRON does not have significant vagal or ganglion blocking properties in the recommended dosage range. Recommended doses of MIVACRON consequently have no clinically significant effects on heart rate and will not counteract the bradycardia produced by many anaesthetic agents or by vagal stimulation during surgery.
In common with other non-depolarising neuromuscular blocking agents, increased sensitivity to mivacurium can be expected in patients with myasthenia gravis, other forms of neuromuscular disease and cachectic patients. Severe acid-base or electrolyte abnormalities may increase or reduce sensitivity to mivacurium.
MIVACRON solution is acidic (approximately pH 4.5) and should not be mixed in the same syringe or administered simultaneously through the same needle with highly alkaline solutions (e.g. barbiturate solutions). It has been shown to be compatible with some commonly used peri-operative drugs supplied as acidic solutions, eg. fentanyl, alfentanil, sufentanil, droperidol and midazolam. Where other anaesthetic agents are administered through the same indwelling needle or cannula as used for MIVACRON, and compatibility has not been demonstrated, it is recommended that each drug is flushed through with physiological saline.
Studies in malignant hyperthermia-susceptible pigs indicated that mivacurium does not trigger this syndrome. MIVACRON has not been studied in malignant hyperthermia-susceptible patients.
No data are available on the long-term use of MIVACRON in patients undergoing mechanical ventilation in the intensive care unit.
Reversal of neuromuscular block: As with other neuromuscular blocking agents, evidence of spontaneous recovery should be observed prior to administration of reversal agent (eg. neostigmine). The use of a peripheral nerve stimulator to evaluate recovery prior to and following reversal of neuromuscular block is strongly recommended.
Animal studies have indicated that mivacurium has no adverse effect on foetal development.
Fertility studies have not been performed.
MIVACRON should not be used during pregnancy unless the expected clinical benefit to the mother outweighs any potential risk to the foetus.
Plasma cholinesterase levels decrease during pregnancy. Mivacurium has been used to maintain neuromuscular block during Caesarean section, but due to the reduced levels of plasma cholinesterase, dosage adjustments to the infusion rate were necessary. A further reduction in the infusion rate may also be required during Caesarean section in patients pre-treated with MgSO4, due to the potentiating effects of Mg++.
It is not known whether mivacurium is excreted in human milk.
This precaution is not relevant to the use of mivacurium. Mivacurium will always be used in combination with a general anaesthetic and therefore the usual precautions relating to performance of tasks following general anaesthesia apply.
The neuromuscular block produced by mivacurium may be potentiated by the concomitant use of inhalational anaesthetics such as enflurane, isoflurane, sevoflurane and halothane.
MIVACRON has been safely administered following suxamethonium-facilitated tracheal intubation. Evidence of spontaneous recovery from suxamethonium should be observed prior to administration of MIVACRON.
In common with all non-depolarising neuromuscular blocking agents the magnitude and/or duration of a non- depolarising neuromuscular block may be increased and infusion requirements may be reduced as a result of interaction with:
Medicines that may reduce plasma cholinesterase activity may also prolong the neuromuscular blocking action of MIVACRON. These include anti-mitotic agents, monoamine oxidase inhibitors, ecothiopate iodide, pancuronium, organophosphates, anticholinesterases, certain hormones, bambuterol.
Rarely, certain medicines may aggravate or unmask latent myasthenia gravis or actually induce a myasthenic syndrome; increased sensitivity to MIVACRON would be consequent on such a development. Such medicines include various antibiotics, β-blockers (propranolol, oxprenolol), antiarrhythmic agents (procainamide, quinidine), antirheumatic medicines (chloroquine, D- pencillamine), trimetaphan, chlorpromazine, steroids, phenytoin and lithium.
The administration of combinations of non-depolarising neuromuscular blocking agents in conjunction with MIVACRON may produce a degree of neuromuscular blockade in excess of that which might be expected from an equipotent total dose of MIVACRON. Any synergistic effect may vary between different medicine combinations.
A depolarising muscle relaxant such as suxamethonium chloride should not be administered to prolong the neuromuscular blocking effects of non- depolarising agents, as this may result in a prolonged and complex block which can be difficult to reverse with anti-cholinesterase medicines.
Immune disorders
Very rare < 1/10,000 (<0.01%)
Severe anaphylactic or anaphylactoid reaction
Cardiac disorders
Uncommon ≥ 1/1,000 and < 1/100 (≥0.1% and <1%)
Transient tachycardia
Vascular disorders
Very common ≥ 1/10 (≥10%)
Flushing
Uncommon ≥ 1/1,000 and < 1/100 (≥0.1% and <1%)
Hypotension
Respiratory, thoracic and mediastinal disorders
Uncommon ≥ 1/1,000 and < 1/100 (≥0.1% and <1%)
Bronchospasm
Skin and subcutaneous tissue disorders
Uncommon ≥ 1/1,000 and < 1/100 (≥0.1% and <1%)
Erythema, urticaria
Reports of skin flushing, erythema, urticaria, hypotension, transient tachycardia or bronchospasm have been attributed to histamine release. These effects are dose-related and more common following initial doses of 0.2 mg/kg or more when given rapidly and are reduced if mivacurium chloride is injected over 30 to 60 seconds or in divided doses over 30 seconds.
Severe anaphylactic or anaphylactoid reactions have been reported in patients receiving mivacurium chloride in conjunction with one or more anaesthetic agents.
Prolonged muscle paralysis and its consequences are the main signs of overdosage with neuromuscular blocking agents. However, the risk of haemodynamic side effects, especially decreases in blood pressure, may be increased.
It is essential to maintain a patent airway together with assisted positive pressure ventilation until spontaneous respiration is adequate.
Full sedation will be required since consciousness is not impaired.
Recovery may be hastened by the administration of anticholinesterase agents accompanied by atropine or glycopyrrolate, once evidence of spontaneous recovery is present. Cardiovascular support may be provided by proper positioning of the patient and administration of fluids or vasopressor agents as required.
MIVACRON is a highly selective, short-acting, non-depolarising neuromuscular blocking agent with a fast recovery profile.
Mivacurium chloride is a mixture of three stereoisomers. The trans-trans and cis-trans stereoisomers comprise 92% to 96% of mivacurium chloride and when studied in cats their neuromuscular blocking potencies are not significantly different from each other or from mivacurium chloride. The cis-cis isomer has been estimated from studies in cats to have one-tenth of the neuromuscular blocking potency of the other two stereoisomers.
Enzymatic hydrolysis by plasma cholinesterase is the primary mechanism for inactivation of mivacurium and yields a quaternary alcohol and a quaternary monoester metabolite. Pharmacological studies in cats and dogs have shown that the metabolites possess insignificant neuromuscular, autonomic or cardiovascular activity at concentrations higher than seen in man.
The termination of the neuromuscular blocking action of mivacurium is mainly dependent on hydrolysis by plasma pseudocholinesterase, which is present at high levels in human plasma.
Multiple degradation/elimination pathways appear to exist for mivacurium (e.g. hydrolysis by liver esterases, elimination in bile and renal excretion).
Mivacurium has been evaluated in four short-term mutagenicity tests.
Mivacurium was non-mutagenic in the Ames Salmonella assay, the mouse lymphoma assay, the human lymphocyte assay and the in vivo rat bone marrow cytogenetic assay.
There is no information available on whether mivacurium has carcinogenic potential.
MIVACRON Injection is acidic (approximately pH 4.5) and should not be mixed with highly alkaline solutions, e.g. barbiturates.
18 months
Store below 25°C.
Protect from light.
Do not freeze.
5mL ampoule Boxes of 5 ampoules
10mL ampoule Boxes of 5 ampoules
Since no antimicrobial preservative is included, MIVACRON Injection must be used under full aseptic conditions and any dilution carried out immediately before use. Any unused solution in open ampoules should be discarded.
MIVACRON Injection has been shown to be compatible with some commonly used peri-operative medicines supplied as acidic solutions.
Where such agents are administered through the same indwelling needle or cannula as used for MIVACRON Injection, and compatibility has not been demonstrated, it is recommended that each medicine is flushed through with physiological saline.
MIVACRON Injection is compatible with the following infusion fluids:-
When diluted with the listed infusion solutions in the proportion of 1 plus 3 (i.e. to give 0.5mg/mL) MIVACRON Injection has been shown to be chemically and physically stable for at least 48 hours at 30°C. However, since the product contains no antimicrobial preservative dilution should be carried out immediately prior to use, administration should commence as soon as possible thereafter and any remaining solution should be discarded.
Prescription Only Medicine
GlaxoSmithKline NZ Limited
AMP Centre
Cnr Albert & Customs Streets
Private Bag 106600
Downtown Auckland
NEW ZEALAND
Phone: (09) 367 2900
Facsimile: (09) 367 2506
11 November 2008
Issue Number 11
MIVACRON™ is a trade mark of the GlaxoSmithKline group of companies.