Bupivacaine
Used for local anaesthetic infiltration and regional anaesthetic infusion
Mechanism of action: Local anaesthetics block nerve conduction by reversibly binding with the alpha subunit of voltage-gated sodium channels in the nerve cell membrane. The site of action is intracellular, requiring local anaesthetics to diffuse across the lipophilic cell membrane.
Presentation: solution for injection, prefilled infusion bags
Suggested dose: may be given as infiltration, or as infusion for regional blockade.
Maximum dose: 2 mg/kg (= 0.8ml/kg of 0.25% bupivacaine or 1.6ml/kg of 0.125%) in any 4-hour period [link to regional anaesthesia guidelines]
- Bupivacaine 0.125% is the usual infusate for regional or wound infusion
- Bupivacaine 0.1% combined with fentanyl (2mcg/ml or 4mcg/ml) is the usual infusate for epidural infusions
- Bupivacaine MUST NOT be given as a bolus on medical or surgical wards unless, rarely, a pain clinician or anaesthetist needs to supplement an infusion.
Absorption: the vascularity of injection sites for local or regional anaesthetic techniques will affect the absorption of local anaesthetic.
From highest absorption to lowest: intercostal > epidural > brachial plexus > subcutaneous
Protein binding: 95%
pKa: 8.1
Metabolism: Primarily hepatic
Elimination: excreted by the kidneys
Half-life: 2.5 hours
Further prescribing information (side effects, contraindications, interactions):