Murexal (Suxamethonium Chloride Dihydrate)

Murexal (suxamethonium chloride) is used in clinical settings that require rapid depolarizing muscle relaxation.

• Tracheal intubation: provides swift muscle relaxation to enable safe placement of an endotracheal tube.
• Surgical procedures: facilitates controlled ventilation and muscle relaxation during operations that require neuromuscular blockade.
• Emergency airway management: allows rapid sequence induction for urgent airway control in critical care situations.

• Suxamethonium chloride acts as an acetylcholine receptor agonist at the nicotinic sites of the motor end‑plate. It binds and activates these receptors, causing an initial depolarization and muscle fasciculation, followed by a sustained depolarized state that renders the end‑plate unresponsive to further stimulation, producing a temporary phase I neuromuscular block.

Suxamethonium chloride may be associated with a range of adverse reactions, which are categorized by frequency.

Common Side Effects

• Transient hyperkalemia: mild increase in serum potassium levels that usually resolves spontaneously.
• Flushing or erythema: temporary skin reddening at the injection site.
• Muscle fasciculations: brief involuntary muscle twitches during onset.
• Elevated intra‑ocular pressure: temporary rise in eye pressure.

Serious or Rare Side Effects

• Malignant hyperthermia: life‑threatening hypermetabolic reaction triggered in susceptible individuals.
• Prolonged apnea: extended respiratory paralysis requiring mechanical ventilation.
• Cardiac arrhythmias: abnormal heart rhythms, especially in patients with electrolyte disturbances.
• Anaphylaxis: severe allergic reaction that can be fatal if not treated promptly.

When using Murexal, clinicians should observe several safety measures.

• Assess patient history: identify known susceptibility to malignant hyperthermia or hyperkalemia.
• Monitor neuromuscular function: use peripheral nerve stimulator to gauge depth of block.
• Avoid in hyperkalemic patients: elevated serum potassium can worsen cardiac risk.
• Use cautiously in cardiac disease: monitor heart rate and blood pressure during administration.
• Adjust for renal impairment: consider reduced clearance in severe renal dysfunction.
• Store at 2-8°C: keep refrigerated, protect from light, do not freeze or shake.

Potential drug interactions with suxamethonium chloride require careful evaluation.

Major Interactions (Avoid)

• Concurrent use with non‑depolarizing neuromuscular blockers: may cause prolonged paralysis.
• Combination with potassium‑increasing agents (e.g., potassium chloride): can exacerbate hyperkalemia.
• Co‑administration with volatile anesthetics that trigger malignant hyperthermia: increases risk of hypermetabolic crisis.

Moderate Interactions (Monitor Closely)

• Anticholinesterases (e.g., neostigmine): may alter duration of block and cause cholinergic side effects.
• Magnesium sulfate: potentiates neuromuscular blockade and may require dose adjustment.
• Beta‑adrenergic blockers: can modify cardiovascular responses during administration.