Bupivacaine

How it works

It reversibly blocks voltage-gated sodium channels in nerve membranes, preventing the initiation and conduction of action potentials and thereby producing local anaesthesia.

Prescribing in practice

• Inadvertent intravascular injection or systemic absorption can cause severe, sometimes refractory cardiotoxicity and CNS toxicity, so aspirate before injection, use incremental dosing and have lipid emulsion and resuscitation facilities available.
• It has a slower onset but longer duration than many other local anaesthetics, making it suitable for prolonged analgesia.
• The plain (non-hyperbaric) preparation is not recommended for intravenous regional anaesthesia owing to the risk of cardiac arrest.

Monitoring

Monitor for early signs of systemic toxicity such as perioral tingling, tinnitus and arrhythmia, with continuous cardiovascular observation during regional blockade.

Counselling the patient

• Tell the patient the treated area will feel numb and weak until the block wears off, so protect it from injury.
• Advise reporting dizziness, ringing in the ears or a metallic taste immediately.

Evidence & guidelines

Safe use is reinforced by professional guidance on management of local anaesthetic systemic toxicity, including lipid emulsion rescue.