Amide local anesthetic
Bupivacaine
Marcaine, Sensorcaine Local anesthetic — gray 0.25% (2.5 mg/mL)0.5% (5 mg/mL)
Long-acting local anesthetic — and the most cardiotoxic.
Typical adult doses
| Indication | Dose | Onset | Duration |
|---|---|---|---|
| Label maximum (healthy adult) | 175 mg plain; 225 mg with epinephrine (≈2.5 mg/kg teaching figure) | — | — |
Mechanism
Sodium-channel blockade; slow dissociation from cardiac Na⁺ channels.
Key effects
- Long-duration block
Watch out for
- Cardiotoxicity — resuscitation is difficult; lipid emulsion is key
- Liposomal bupivacaine has its own label and maximum
Pimp questions
Pimp question
Why is bupivacaine more cardiotoxic than lidocaine?
Answer
It binds cardiac sodium channels avidly and dissociates slowly (“fast-in, slow-out”).