Formulary
Suxamethonium chloride: Indications, Dosing, Side Effects and Interactions
Suxamethonium acts by mimicking acetylcholine at the neuromuscular junction but hydrolysis is much slower than for acetylcholine; depolarisation is therefore...
MedNext Academy | 3 min read
Suxamethonium chloride: Indications, Dosing, Side Effects and Interactions
Suxamethonium acts by mimicking acetylcholine at the neuromuscular junction but hydrolysis is much slower than for acetylcholine; depolarisation is therefore...
Drug action
Suxamethonium acts by mimicking acetylcholine at the neuromuscular junction but hydrolysis is much slower than for acetylcholine; depolarisation is therefore prolonged, resulting in neuromuscular blockade.
Indications and dose
**Neuromuscular blockade (short duration) during surgery and intubation**
- **Adult** (By Intravenous Injection): 1-1.5 mg/kg.
**Neuromuscular blockade (short duration) during surgery for suxamethonium chloride**
- **Neonate** (By intravenous injection): 2 mg/kg, produces 5-10 minutes neuromuscular blockade.
- **Child 1-11 months** (By intravenous injection): 2 mg/kg.
- **Child 1-17 years** (By intravenous injection): 1 mg/kg.
- **Neonate** (By intramuscular injection): Up to 4 mg/kg, produces 10-30 minutes neuromuscular blockade.
- **Child 1-11 months** (By intramuscular injection): Up to 5 mg/kg.
- **Child 1-11 years** (By intramuscular injection): Up to 4 mg/kg (max. per dose 150 mg).
Cautions
Cardiac disease; neuromuscular disease; raised intra-ocular pressure (avoid in penetrating eye injury); respiratory disease; severe sepsis (risk of hyperkalaemia)
Contraindications
Hyperkalaemia; low plasma-cholinesterase activity (including severe liver disease); major trauma; neurological disease involving acute wasting of major muscle; personal or family history of congenital myotonic disease; personal or family history of malignant hyperthermia; prolonged immobilisation (risk of hyperkalaemia); severe burns; skeletal muscle myopathies (e.g. Duchenne muscular dystrophy)
Side effects
Common or very common Arrhythmias; bradycardia (may occur with repeated doses); flushing; muscle contractions involuntary; myoglobinuria; myopathy; post procedural muscle pain; rash Rare or very rare Apnoea; cardiac arrest; hypersensitivity; malignant hyperthermia; respiratory disorders; trismus Side-effects, further information Premedication with atropine reduces bradycardia associated with suxamethonium use.
Interactions
**Other interactions (2):**
- These include: Antibacterials Enhanced effects of suxamethonium with Aminoglycosides Clindamycin, polymyxins and vancomycin Piperacillin Antimalarials Quinine and chloroquine - effects of...
- The following have potentially adverse effects on plasma cholinesterase activity Aprotinin Oestrogens and oral contraceptives Oxytocin High-dose steroids Liver disease, cancer, pregnancy,...
Pregnancy
Mildly prolonged maternal neuromuscular blockade may occur.
Breast feeding
Unlikely to be present in breast milk in significant amounts (ionised at physiological pH). Breast-feeding may be resumed once the mother recovered from neuromuscular block.
Hepatic impairment
Manufacturer advises caution, particularly in end stage hepatic failure (increased risk of prolonged apnoea due to reduced hepatic synthesis of plasma cholinesterase).
Medicinal forms
Solution
Clinical governance
**Author:** MedNext Clinical Team. **Clinical reviewer:** Dr Shameer Deen, MBBS, MS, MRCS. **Sources:** BNF, Indian Pharmacopoeia, CIMS India. **Correction:** Report errors at support@mednext.academy.
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