Mepivacaine
Carbocaine · Polocaine
Amide local anesthetic (intermediate-acting)
Na⁺-channel blocker. Intermediate duration; less intrinsic vasodilation than lidocaine → slightly longer duration without epinephrine.
Indications
- •Infiltration
- •Peripheral nerve block
- •Epidural
- •Dental (without vasoconstrictor — useful when epi contraindicated)
Dosing
| Context | Adult | Pediatric |
|---|---|---|
| Nerve block / infiltration | 1–2%; max 7 mg/kg with epi | — |
Maximum dose
4.5 mg/kg plain (absolute max 400 mg) · 7 mg/kg with epi (absolute max 550 mg)
Max-dose calculator
single-injection infiltration / blockPlain
315 mg
With epinephrine
490 mg
| Concentration | Max volume (plain) | Max volume (with epi) |
|---|---|---|
| 1% (10 mg/mL) | 31.5 mL | 49 mL |
| 1.5% (15 mg/mL) | 21 mL | 32.7 mL |
| 2% (20 mg/mL) | 15.8 mL | 24.5 mL |
Intermediate amide; slightly longer plain duration than lidocaine. Avoid in OB/neonates. Education only — confirm against the package insert. Max doses are not additive across agents; account for total LA when mixing.
Pharmacokinetics
Onset fast. Duration 90–180 min (longer than lidocaine plain). Amide hepatic metabolism; prolonged/neurotoxic in NEONATES (immature metabolism).
Side effects
- !LAST
- !Transient neurologic symptoms (intrathecal — like lidocaine)
- !Avoid in OB/neonates (slow fetal metabolism)
Contraindications
- ×Amide allergy (rare)
- ×Obstetric use (prolonged fetal levels)
Clinical pearls
- ★Longer duration than plain lidocaine (less vasodilation) — useful when a vasoconstrictor is contraindicated.
- ★Avoid in obstetrics/neonates — immature metabolism → prolonged fetal drug levels.
Other drugs in Local Anesthetics
- Lidocaine
Blocks voltage-gated Na⁺ channels in nerves (LA) and cardiac myocytes (antiarrhythmic).
- Bupivacaine
Voltage-gated Na⁺ channel blocker. Higher protein binding and lipid solubility than lidocaine → longer duration but greater cardiotoxicity.
- Ropivacaine
S-enantiomer of propivacaine. Less lipid-soluble than bupivacaine → less cardiotoxicity but slightly less potency.
- Tetracaine
Blocks voltage-gated Na⁺ channels. Long-acting ester, metabolized by plasma cholinesterase. High potency + toxicity.
- Chloroprocaine
Na⁺-channel blocker. Extremely rapid plasma-cholinesterase metabolism (half-life seconds) → lowest systemic toxicity of the LAs, ideal for OB epidural top-up.
- Procaine
Na⁺-channel blocker; prototype ester LA. Plasma-cholinesterase metabolized to PABA.
- Prilocaine
Na⁺-channel blocker. Metabolized to o-toluidine → oxidizes hemoglobin → methemoglobinemia at high doses.
- Levobupivacaine
The S(−)-enantiomer of bupivacaine → similar block with LESS cardiotoxicity + CNS toxicity than racemic bupivacaine.
Browse all classes: /reference/drugs
Suggested reading
- •Stoelting & Hines, Pharmacology & Physiology in Anesthetic Practice, 6e
- •FDA package insert
- •ASRA LAST checklist, 2020
