Complete dosing reference for bupivacaine — adult and pediatric max doses, age-based tiers, cardiotoxicity warnings, IVRA contraindication, available concentrations, and pharmacokinetics.
| Formulation | Max Dose (mg/kg) | Absolute Max (mg) |
|---|---|---|
| Bupivacaine (plain) | 2–2.5 mg/kg | 150 mg |
| Bupivacaine + Epinephrine | 3 mg/kg | 225 mg |
Pediatric doses are derived from adult max doses using age-based percentage reductions that account for immature hepatic metabolism (CYP3A4 maturation at 9–12 months).
| Age Tier | % of Adult Dose | Without Epi (mg/kg) | With Epi (mg/kg) |
|---|---|---|---|
| Neonate (<1 month) | 50% | 1–1.25 mg/kg | 1.5 mg/kg |
| Young Infant (1–<6 months) | 70% | 1.4–1.75 mg/kg | 2.1 mg/kg |
| Older Infant (6–<12 months) | 87.5% | 1.75–2.19 mg/kg | 2.625 mg/kg |
| Child (1–7 years) | 100% | 2–2.5 mg/kg | 3 mg/kg |
| Adolescent (8–17 years) | 100% | 2–2.5 mg/kg | 3 mg/kg |
Bupivacaine has a low CC:CNS ratio (cardiac collapse to CNS toxicity ratio), meaning cardiac arrest can occur with minimal preceding neurological warning signs. It binds sodium channels with high affinity and slow dissociation ("fast-in, slow-out"), making resuscitation from bupivacaine-induced cardiac arrest extremely difficult.
Intralipid emulsion therapy (20%) should be immediately available whenever bupivacaine is used in significant doses. Refer to the LAST Protocol for emergency management.
Bupivacaine must never be used for intravenous regional anesthesia. Tourniquet release delivers a bolus of bupivacaine directly into the systemic circulation, risking fatal cardiac arrest. This contraindication is absolute regardless of dose or tourniquet time. Use lidocaine for IVRA instead.
| Concentration | mg/mL | Common Use |
|---|---|---|
| 0.125% | 1.25 mg/mL | Epidural infusions, peripheral nerve infusions |
| 0.25% | 2.5 mg/mL | Field blocks, peripheral nerve blocks |
| 0.5% | 5 mg/mL | Peripheral nerve blocks, epidural anesthesia |
| 0.75% | 7.5 mg/mL | Spinal anesthesia (hyperbaric), dense surgical blocks |
| Property | Value |
|---|---|
| Half-life | 2.7 hours |
| Metabolism | Hepatic — CYP3A4 |
| CYP3A4 maturation | 9–12 months of age |
| Protein binding | ~95% (alpha-1 acid glycoprotein) |
| Onset | Slow (long-acting amide) |
| Duration | Long (4–8 hours depending on site and epi use) |
| Neonatal safety rank | 5/5 — avoid if possible |
| Cardiotoxicity rank | 5/5 — most cardiotoxic |
Levobupivacaine is the S-enantiomer of bupivacaine with similar anesthetic potency but reduced cardiotoxicity and CNS toxicity. It has a higher CC:CNS ratio, providing a greater margin of safety. Levobupivacaine is particularly preferred in neonatal and pediatric populations where CYP3A4 immaturity increases bupivacaine toxicity risk, and in high-volume blocks where systemic absorption is a concern.
MaxLocal auto-calculates weight-based doses for bupivacaine and all common local anesthetics with pediatric age-based tiers, fractional toxicity tracking, and LAST protocol reference — all offline.