Mivacron (Mivacurium)

Mivacurium is a non‑depolarizing neuromuscular blocker used in the peri‑operative setting to achieve muscle relaxation.

• Facilitation of endotracheal intubation: produces a quick, short‑lasting neuromuscular block that enables smooth airway instrumentation in elective and emergency surgeries.
• Muscle relaxation during surgery: sustains skeletal muscle paralysis for the duration of the operation, allowing surgeons to work without patient movement.
• Adjunct to general anesthesia: deepens the anesthetic plane and reduces the need for additional muscle relaxants during complex procedures.

• Mivacurium acts as a competitive antagonist at nicotinic acetylcholine receptors located on the motor end‑plate of skeletal muscle. By binding to these receptors without activating them, it prevents acetylcholine from triggering depolarization, thereby inhibiting transmission of the nerve impulse and producing a reversible, dose‑dependent muscle relaxation. The effect is rapid in onset and short in duration due to hydrolysis by plasma cholinesterases.

Mivacurium may be associated with a range of adverse reactions, varying from mild to severe.

Common Side Effects

• Transient facial flushing: brief redness and warmth of the face and neck that resolves spontaneously.
• Mild hypotension: temporary reduction in blood pressure, usually self‑limiting and managed with fluid support.
• Tachycardia: increase in heart rate observed during induction, often mild and transient.
• Pruritus at the injection site: itching sensation around the IV site that may be relieved with antihistamines.

Serious or Rare Side Effects

• Anaphylaxis: severe, potentially life‑threatening allergic reaction characterized by bronchospasm, urticaria, and circulatory collapse.
• Prolonged apnea: unexpected extension of respiratory muscle paralysis requiring extended ventilatory support.
• Hyperkalemia: rise in serum potassium, particularly in patients with underlying metabolic disorders.
• Methemoglobinemia: rare oxidation of hemoglobin leading to reduced oxygen‑carrying capacity and cyanosis.

When using Mivacurium, clinicians should observe specific precautions to ensure patient safety and maintain product integrity.

• Patient assessment: evaluate neuromuscular function and baseline respiratory status before administration.
• Contraindications: avoid use in patients with known hypersensitivity to mivacurium or related compounds.
• Monitoring: continuously monitor neuromuscular transmission, blood pressure, and heart rate during infusion.
• Drug interactions: adjust dosing when co‑administered with other neuromuscular blockers or cholinesterase inhibitors.
• Reversal planning: be prepared to use anticholinesterase agents for rapid recovery if prolonged blockade occurs.
• Store at ambient temperature: keep vials below 25 °C, protected from light and moisture in the original packaging.

Mivacurium may interact with several agents that influence neuromuscular transmission or plasma cholinesterase activity.

Major Interactions (Avoid)

• Anticholinesterases (e.g., neostigmine, pyridostigmine): can potentiate or prolong the block, leading to unpredictable muscle relaxation.
• Aminoglycoside antibiotics (e.g., gentamicin, amikacin): enhance neuromuscular blockade and increase risk of respiratory failure.

Moderate Interactions (Monitor Closely)

• Inhalational anesthetics (e.g., sevoflurane, desflurane): may augment the effect of mivacurium, requiring dose adjustment.
• Magnesium sulfate: can intensify blockade, necessitating careful monitoring of neuromuscular function.
• Lithium therapy: may prolong neuromuscular blockade duration.
• Plasma cholinesterase deficiency (genetic or acquired): results in prolonged drug action, requiring extended ventilation support.