Suxamethonium

Muscle Relaxant · Depolarizing muscle relaxant (short-acting)

Indications

Neuromuscular blockade (short duration).

Dosage

Adults: By IV injection, initially 1 mg/kg; maintenance, usually 0.5-1 mg/kg at 5-10 min intervals; max 500 mg/hr. By IV infusion, a solution containing 1-2 mg/mL (0.1-0.2%), 2.5-4 mg/min; max 500 mg/hr. Children: Neuromuscular blockade (short duration) during surgery: IV injection: Neonate, 2 mg/kg produces 5-10 minutes neuromuscular blockade; 1 mth-1 yr, 2 mg/kg; 1-18 yr, 1 mg/kg IM (onset in 2-3 minutes): Neonate, up to 4 mg/kg produces 10-30 minutes neuromuscular blockade; 1 mth-1 yr, up to 4-5 mg/kg; 1-12 yr, up to 4 mg/kg, max 150 mg.

Administration

Administer via IV or IM route. Stability: Refrigerate. Stable at room temperature for 14 days.

Adverse Effects

Postoperative muscle pain, myoglobinuria, myoglobinaemia; tachycardia, arrhythmias, cardiac arrest, hypertension, bronchospasm, apnoea, prolonged respiratory depression, anaphylactic reactions; hyperkalaemia; hyperthermia; increased gastric pressure; rash, flushing.

Risk Factor (Pregnancy/Lactation)

Pregnancy: Risk cannot be ruled out. Lactation: Caution advised or effect undetermined. Contraindications: Family history of malignant hyperthermia, low plasma cholinesterase activity (including severe liver disease), hyperkalaemia; major trauma, severe burns, neurological disease involving acute wasting of major muscle, prolonged immobilisation-risk of hyperkalaemia, personal or family history of congenital myotonic disease, Duchenne muscular dystrophy. Precautions: Patients with cardiac, respiratory or neuromuscular disease; raised intra-ocular pressure (avoid in penetrating eye injury); severe sepsis (risk of hyperkalaemia).

Interactions

Anticholinesterase, cyclophosphamide, oral contraceptives, lidocaine, pancuronium, lithium, magnesium salts, chloroquine, metoclopramide, terbutaline, procaine, anaesthetics, calcium channel blockers, antiarrhythmics, immunosuppressants.

Advice to Patient

Before administration, patient is usually unconscious. Continuous monitoring is required during and after administration. After muscle tone becomes normal, do not change position and rise up without help. Contact prescriber if there is difficulty in breathing, muscle tremors, fast heartbeat, skin rash, hives.

Pharmacokinetics

Onset: 30 seconds. Duration: 3-5 mins. Absorption: Rapid. Metabolism: Rapidly hydrolyzed by plasma cholinesterase. Excretion: Urine (10% as unchanged drug).

Compiled by Healify Pharmacy from published drug references. How we compile it →

Always consult a pharmacist or doctor.