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Pronunciation:

(me PIV a kane & lee voe nor DEF rin)

U.S. Brand Names:

Carbocaine® 2% with Neo-Cobefrin® [DSC]

Synonyms:

Levonordefrin and Mepivacaine (Dental)

Generic Available:

Canadian Brand Names:

Polocaine® 2% and Levonordefrin 1:20,000

Use - Dental:

Amide-type anesthetic used for local infiltration anesthesia; injection near nerve trunks to produce nerve block

Pregnancy Risk Factor:

Contraindications:

Hypersensitivity to local anesthetics of the amide-type or any component of the formulation

Warnings/Precautions:

Should be avoided in patients with uncontrolled hyperthyroidism. Should be used in minimal amounts in patients with significant cardiovascular problems (because of levonordefrin component). Aspirate the syringe after tissue penetration and before injection to minimize chance of direct vascular injection.

Adverse Reactions:

Degree of adverse effects in the CNS and cardiovascular system is directly related to the blood levels of mepivacaine. The effects below are more likely to occur after systemic administration rather than infiltration.

Cardiovascular: Myocardial effects include a decrease in contraction force as well as a decrease in electrical excitability and myocardial conduction rate resulting in bradycardia and reduction in cardiac output.

Central nervous system: High blood levels result in anxiety, restlessness, disorientation, confusion, dizziness, and seizure. This is followed by depression of CNS resulting in somnolence, unconsciousness and possible respiratory arrest. In some cases, symptoms of CNS stimulation may be absent and the primary CNS effects are somnolence and unconsciousness.

Gastrointestinal: Nausea and vomiting may occur

Hypersensitivity reactions: Extremely rare, but may be manifest as dermatologic reactions and edema at injection site. Asthmatic syndromes have occurred. Patients may exhibit hypersensitivity to bisulfites contained in local anesthetic solution to prevent oxidation of levonordefrin. In general, patients reacting to bisulfites have a history of asthma and their airways are hyper-reactive to asthmatic syndrome.

Neuromuscular & skeletal: Tremors

Psychogenic reactions: It is common to misinterpret psychogenic responses to local anesthetic injection as an allergic reaction. Intraoral injections are perceived by many patients as a stressful procedure in dentistry. Common symptoms to this stress are diaphoresis, palpitation, hyperventilation, generalized pallor and a fainting feeling.

Drug Interactions:

Due to levonordefrin component, use with tricyclic antidepressants or MAO inhibitors could result in increased pressor response; use with nonselective beta-blockers (ie, propranolol) could result in serious hypertension and reflex bradycardia

Mechanism of Action:

Local anesthetics bind selectively to the intracellular surface of sodium channels to block influx of sodium into the axon. As a result, depolarization necessary for action potential propagation and subsequent nerve function is prevented. The block at the sodium channel is reversible. When drug diffuses away from the axon, sodium channel function is restored and nerve propagation returns.

Levonordefrin prolongs the duration of the anesthetic actions of mepivacaine by causing vasoconstriction (alpha adrenergic receptor agonist) of the vasculature surrounding the nerve axons. This prevents the diffusion of mepivacaine away from the nerves resulting in a longer retention in the axon.

Pharmacodynamics/Kinetics:

Duration: Upper jaw: 1-2.5 hours; Lower jaw: 2.5-5.5 hours

Infiltration: 50 minutes

Inferior alveolar block: 60-75 minutes

Dosage:

Children <10 years: Maximum pediatric dosage must be carefully calculated on the basis of patient's weight but should not exceed 6.6 mg/kg of body weight or 180 mg of mepivacaine hydrochloride as a 2% solution with levonordefrin 1:20,000

Children >10 years and Adults:

Dental infiltration and nerve block, single site: 36 mg (1.8 mL) of mepivacaine hydrochloride as a 2% solution with levonordefrin 1:20,000

Entire oral cavity: 180 mg (9 mL) of mepivacaine hydrochloride as a 2% solution with levonordefrin 1:20,000; up to a maximum of 6.6 mg/kg of body weight but not to exceed 400 mg of mepivacaine hydrochloride per appointment. The effective anesthetic dose varies with procedure, intensity of anesthesia needed, duration of anesthesia required, and physical condition of the patient. Always use the lowest effective dose along with careful aspiration.

The following numbers of dental carpules (1.8 mL) provide the indicated amounts of mepivacaine hydrochloride 2% and levonordefrin 1:20,000. See table.

Note::

# of Cartridges (1.8 mL)	Mg Mepivacaine (2%)	Mg Vasoconstrictor (Levonordefrin 1:20,000)
1	36	0.090
2	72	0.180
3	108	0.270
4	144	0.360
5	180	0.450
6	216	0.540
7	252	0.630
8	288	0.720
9	324	0.810
10	360	0.900

Note: Adult and children doses of mepivacaine hydrochloride with levonordefrin cited from USP Dispensing Information (USP DI), 17th ed, The United States Pharmacopeial Convention, Inc, Rockville, MD, 1997, 139.

Dental Health: Effects on Dental Treatment:

It is common to misinterpret psychogenic responses to local anesthetic injection as an allergic reaction. Intraoral injections are perceived by many patients as a stressful procedure in dentistry. Common symptoms to this stress are diaphoresis, palpitations, hyperventilation, generalized pallor and a fainting feeling. Patients may exhibit hypersensitivity to bisulfites contained in local anesthetic solution to prevent oxidation of levonordefrin. In general, patients reacting to bisulfites have a history of asthma and their airways are hyper-reactive to asthmatic syndrome.

Degree of adverse effects in the CNS and cardiovascular system is directly related to the blood levels of mepivacaine (frequency not defined; more likely to occur after systemic administration rather than infiltration): Bradycardia and reduction in cardiac output, nausea, vomiting, tremors, hypersensitivity reactions (extremely rare; may be manifest as dermatologic reactions and edema at injection site), asthmatic syndromes

High blood levels: Anxiety, restlessness, disorientation, confusion, dizziness, and seizures, followed by CNS depression resulting in somnolence, unconsciousness and possible respiratory arrest.

In some cases, symptoms of CNS stimulation may be absent and the primary CNS effects are somnolence and unconsciousness.

Dental Health: Vasoconstrictor/Local Anesthetic Precautions:

No information available to require special precautions

Dosage Forms:

Injection: Mepivacaine hydrochloride 2% with levonordefrin 1:20,000 (1.8 mL dental cartridges) [DSC]

International Brand Names:

Polocaine® 2% and Levonordefrin 1:20,000 (CA)

References

Ayoub ST and Coleman AE, "A Review of Local Anesthetics,"Gen Dent, 1992, 40(4):285-7, 289-90.

Jastak JT and Yagiela JA, "Vasoconstrictors and Local Anesthesia: A Review and Rationale for Use,"J Am Dent Assoc, 1983, 107(4):623-30.

MacKenzie TA and Young ER, "Local Anesthetic Update,"Anesth Prog, 1993, 40(2):29-34.

Wynn RL, "Epinephrine Interactions With Beta-Blockers,"Gen Dent, 1994, 42(1):16, 18.

Wynn RL, "Recent Research on Mechanisms of Local Anesthetics,"Gen Dent, 1995, 43(4):316-8.

Yagiela JA, "Local Anesthetics,"Anesth Prog, 1991, 38(4-5):128-41.

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