MIVACRON

What it is

MIVACRON is a highly selective, non-depolarising neuromuscular blocking agent with a fast recovery profile and a short duration of action. MIVACRON injection is a sterile, non-pyrogenic solution containing mivacurium chloride equivalent to 2 mg/mL mivacurium. This formulation contains no antimicrobial preservative and is intended for single patient use.

Approved indications

— As an adjunct to general anaesthesia to relax skeletal muscles and to facilitate tracheal intubation and mechanical ventilation.

Dosing overview

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 (ED 95) is 0.07 mg/kg (range 0.06 to 0.09) in adults receiving narcotic anaesthesia. A dose of 0.2 mg/kg, administered over 30 seconds, generally produced good to excellent conditions for tracheal intubation within 2 to 2.5 minutes. A dose of 0.25 mg/kg administered as a divided dose (0.15 mg/kg followed 30 seconds later by 0.1 mg/kg) produced good to excellent conditions for tracheal intubation within 1.5 to 2.0 minutes of completion of administration of the first dose portion. Doses of 0.07, 0.15, 0.20 and 0.25 mg/kg produced clinically effective block for approximately 13, 16, 20 and 23 minutes respectively.

Key safety warnings

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. MIVACRON has the potential to cause histamine release and therefore there is a potential for anaphylactoid reactions in some individuals. For this reason it is essential that appropriate resuscitative equipment be immediately available. Associated with the use of MIVACRON there have been reports of skin flushing, erythema, urticaria, mild transient hypotension, transient tachycardia or bronchospasm which have been attributed to histamine release. These effects are dose related and are more common if initial doses of 0.2 mg/kg or more are given rapidly. The risk of histamine-related side effects is reduced if MIVACRON is injected over 30 to 60 seconds or as divided doses over 30 seconds, when higher doses are employed. Prolonged and intensified neuromuscular blockade following mivacurium may occur secondary to reduced plasma cholinesterase activity in states or pathological conditions including physiological variation as in pregnancy and the puerperium, genetically determined abnormalities of plasma cholinesterase, severe generalised tetanus, tuberculosis and other severe or chronic infections, chronic debilitating disease, malignancy, chronic anaemia and malnutrition, myxoedema and collagen diseases, decompensated heart disease, peptic ulcer, burns, end-stage hepatic failure, acute, chronic or end-stage renal failure, and iatrogenic causes following plasma exchange, plasmapheresis, cardiopulmonary bypass, and as a result of concomitant drug therapy.

Contraindications

MIVACRON injection should not be administered to patients known to have an allergic hypersensitivity to mivacurium. MIVACRON is contra-indicated in patients known to be homozygous for atypical plasma cholinesterase gene.

Regulatory history

MIVACRON was first registered on the Australian Register of Therapeutic Goods on 16 May 1994.