Bupivacaine/Meloxicam (Zynrelef)
Zynrelef
Extended-release bupivacaine + meloxicam wound instillation
Bupivacaine (LA) + low-dose meloxicam (NSAID lowers local pH to enhance bupivacaine release/uptake) applied into the surgical site for up to ~72 h analgesia.
Indications
- •Post-surgical analgesia — soft-tissue / small-to-medium open procedures (site instillation)
Dosing
| Context | Adult | Pediatric |
|---|---|---|
| Instillation | Procedure-specific fixed volume applied without a needle before closure | — |
Pharmacokinetics
Extended local release ~72 h.
Side effects
- !LAST (bupivacaine)
- !NSAID effects (meloxicam — small systemic exposure)
- !Impaired wound healing (theoretical)
Contraindications
- ×NSAID contraindication (severe)
- ×Known bupivacaine/meloxicam hypersensitivity
Clinical pearls
- ★Combines LA + NSAID at the wound — part of opioid-sparing multimodal/ERAS.
- ★Still carries bupivacaine LAST risk — count it in the total LA dose.
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.
Suggested reading
- •Stoelting & Hines, Pharmacology & Physiology in Anesthetic Practice, 6e
- •FDA package insert
- •ASRA LAST checklist, 2020
