Overview
Mepivacaine is an intermediate-acting amide local anesthetic used for infiltration, nerve block, epidural, and caudal anesthesia. It has a rapid onset (3-5 minutes) and duration of 1.5-3 hours, with less vasodilation than lidocaine, reducing the need for epinephrine in some cases.
Mechanism of Action
Blocks voltage-gated sodium channels in neuronal membranes, preventing depolarization and propagation of action potentials, thereby inhibiting nerve conduction and producing local anesthesia.
Indications
- Local anesthesia for dental procedures
- Infiltration anesthesia
- Peripheral nerve blocks
- Epidural anesthesia (obstetric and surgical)
- Caudal anesthesia
Dosage
Dosage varies by procedure, patient status, and concentration. Typical dental use: 1.8-3.6 mL of 3% solution (54-108 mg). Maximum recommended dose: 400 mg (6.6 mg/kg) without epinephrine; 500 mg (8 mg/kg) with epinephrine. Always use the lowest effective dose.
Contraindications
- Hypersensitivity to mepivacaine or other amide anesthetics
- Severe hypotension
- Heart block
- Local infection at injection site
- Septicemia
Side Effects
- CNS: dizziness, tinnitus, drowsiness, seizures (with toxicity)
- Cardiovascular: hypotension, bradycardia, arrhythmias (with toxicity)
- Local: pain at injection site, paresthesia
- Allergic: rash, urticaria (rare)
- Methemoglobinemia (rare)
Interactions
- MAO inhibitors, tricyclic antidepressants: may increase risk of hypotension
- Beta-blockers, calcium channel blockers: may enhance cardiac depression
- Other local anesthetics: additive toxicity risk
- Vasoconstrictors (e.g., epinephrine): may alter absorption and effects