Mivacron (Mivacurium Chloride)

Mivacron is a neuromuscular blocking agent used to produce skeletal muscle relaxation during procedures that require controlled ventilation.

• Facilitation of endotracheal intubation: provides rapid muscle relaxation to allow safe placement of the airway tube.
• Muscle relaxation during surgical procedures: maintains a relaxed surgical field throughout operations under general anesthesia.
• Adjunct to general anesthesia: enhances anesthetic depth and prevents patient movement during invasive procedures.

• Mivacurium chloride acts as a competitive antagonist at nicotinic acetylcholine receptors on the motor end‑plate of the neuromuscular junction. By binding without activating the receptor, it blocks acetylcholine‑mediated depolarization, preventing sodium influx and inhibiting skeletal muscle contraction. The effect is a rapid, reversible paralysis that is terminated as plasma cholinesterases hydrolyze the drug.

Mivacron may be associated with a range of adverse reactions, which are categorized by frequency and severity.

Common Side Effects

• Transient flushing: brief skin reddening that typically resolves within minutes after injection.
• Histamine release: mild itching, urticaria, or rash occurring in susceptible patients.
• Bradycardia: temporary slowing of heart rate that may be observed during infusion.

Serious or Rare Side Effects

• Anaphylaxis: severe allergic reaction with airway swelling, hypotension, and possible shock.
• Prolonged neuromuscular blockade: extended paralysis lasting longer than expected, requiring prolonged ventilation support.
• Cardiac arrhythmias: irregular heart rhythms, such as ventricular ectopy, that may need medical intervention.

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

• Patient assessment: evaluate for known hypersensitivity to mivacurium or related compounds before administration.
• Cardiovascular monitoring: continuously monitor heart rate and blood pressure due to risk of bradycardia and hypotension.
• Respiratory support: ensure availability of ventilatory assistance as muscle paralysis can impair spontaneous breathing.
• Drug interactions: avoid concurrent use with other histamine‑releasing agents that may exacerbate reactions.
• Reversal agents: be prepared to administer cholinesterase inhibitors (e.g., neostigmine) if prolonged blockade occurs.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake the vial.

Mivacron can interact with other medications, influencing its efficacy or safety profile.

Major Interactions (Avoid)

• Anticholinesterases (e.g., neostigmine, pyridostigmine): may antagonize the neuromuscular blockade, reducing effectiveness.
• Potassium channel blockers (e.g., quinidine): increase risk of cardiac arrhythmias when combined.

Moderate Interactions (Monitor Closely)

• Histamine‑releasing drugs (e.g., morphine, atracurium): may augment flushing or hypotension.
• Beta‑blockers: can enhance bradycardic response during infusion.
• Inhalational anesthetics (e.g., sevoflurane): may potentiate neuromuscular blockade, requiring dose adjustment.