Mepivacaine Hydrochloride

AHFS Class: Local Anesthetics (72:00)

ATC Class: N01BB53
VA Class: CN204

View the associated Essentials monograph.

Introduction

Mepivacaine hydrochloride is an intermediate-acting local anesthetic of the amide type.

Uses

Mepivacaine hydrochloride is used for infiltration anesthesia and for peripheral or sympathetic nerve block and epidural (including caudal) block. The drug is not used for spinal anesthesia. The effectiveness of mepivacaine as a topical anesthetic has not been fully investigated.

Dosage and Administration

Mepivacaine hydrochloride may be administered by infiltration, by epidural (including caudal) block, or by peripheral or sympathetic nerve block. Mepivacaine hydrochloride solutions containing preservatives should not be used for epidural or caudal block. Partially used bottles of solutions that do not contain preservatives should be discarded. Dosage of mepivacaine hydrochloride varies with the anesthetic procedure, the degree of anesthesia required, and the individual patient response. The usual dosages should generally be reduced in children and in geriatric, debilitated, or acutely ill patients. The smallest dose and lowest concentration required to produce the desired effect should be used. Resuscitative equipment and drugs that may be required for treatment of adverse reactions should be immediately available when mepivacaine is administered. For specific procedures and techniques of administration, specialized references should be consulted.

The maximum single dose (or the total of a series of doses given in one procedure) of mepivacaine hydrochloride for unsedated, healthy normal-sized adults should usually not exceed 400 mg. Maximum doses of 7 mg/kg (550 mg) have been administered without adverse effects, but these doses are not recommended except in unusual circumstances, and such doses should not be repeated at intervals of less than 1.5 hours. The total dose for any 24-hour period should not exceed 1 g. The pediatric dose should not exceed 5–6 mg/kg, especially in children weighing less than 13.6 kg. In children younger than 3 years of age or weighing less than 13.6 kg, concentrations less than 2% (e.g., 0.5–1.5%) should be used.

For infiltration anesthesia, up to 40 mL of a 1% solution (400 mg) of mepivacaine hydrochloride or 80 mL of a 0.5% solution (400 mg) may be given; a 0.5% solution may be prepared by diluting the 1% solution with 0.9% sodium chloride injection.

For cervical, brachial, intercostal, or pudendal nerve block, 5–40 mL of a 1% solution (50–400 mg) or 5–20 mL of a 2% solution (100–400 mg) may be given depending on the area and degree of anesthesia required; for pudendal block, one-half the total dose is injected on each side. For combined paracervical and pudendal block by the transvaginal route, up to 15 mL of a 1% solution (150 mg) is injected on each side. For paracervical block, up to 10 mL of a 1% solution (100 mg) may be injected on each side every 90 minutes; injections should be made slowly, with an interval of 5 minutes between sides. For therapeutic nerve block in the management of pain, 1–5 mL of a 1 or 2% solution (10–100 mg) may be given.

Solutions of 1, 1.5, or 2% mepivacaine hydrochloride containing no preservatives may be used in epidural or caudal anesthesia. To prevent intravascular or subarachnoid injection of a large epidural dose of mepivacaine hydrochloride, a test dose of 5 mL of anesthetic solution should be injected at least 5 minutes prior to administering the total dose; motor paralysis and extensive sensory anesthesia indicate subarachnoid injection. For caudal epidural block, the usual dose of mepivacaine hydrochloride is 15–30 mL of a 1% solution (150–300 mg), 10–25 mL of a 1.5% solution (150–375 mg), or 10–20 mL of a 2% solution (200–400 mg) of mepivacaine hydrochloride.

In dental infiltration or nerve block procedures, the usual dose is 1.8 mL (36 mg) of a 2% solution also containing levonordefrin or 1.8 mL (54 mg) of a 3% solution. Infiltration or injection should be performed slowly with frequent aspiration. In adults, a total dose of 9 mL (180 mg as the 2% solution or 270 mg as the 3% solution) is usually adequate to produce local anesthesia of the entire oral cavity; however, a dose of up to 3 mg/kg may be administered. The total dose for all injection sites in a single dental sitting should not exceed 400 mg in adults. In children, the maximum dose for dental blocks must be carefully calculated and should not exceed 9 mL (180 mg as the 2% solution or 270 mg as the 3% solution). The manufacturer recommends that the maximum pediatric dose be calculated as follows:

Maximum Dose (in mg) = (Child’s Weight (in pounds)/150) × 400 mg

Cautions

Mepivacaine shares the toxic potentials of the local anesthetics, and the usual precautions of local anesthetic therapy should be observed. (See Cautions in the Local Anesthetics, Parenteral, General Statement 72:00.)

Some commercially available formulations of mepivacaine hydrochloride contain acetone sodium bisulfite, a sulfite that may cause allergic-type reactions, including anaphylaxis and life-threatening or less severe asthmatic episodes, in certain susceptible individuals. The overall prevalence of sulfite sensitivity in the general population is unknown but probably low; such sensitivity appears to occur more frequently in asthmatic than in nonasthmatic individuals.

Pharmacokinetics

Mepivacaine produces less vasodilation and has a more rapid onset and longer duration than does lidocaine. When used for epidural block, the onset of action of a 2% solution of mepivacaine hydrochloride is about 7–15 minutes and the duration of anesthesia is 115–150 minutes. When used for caudal block, the duration of action of a 1–2% solution is about 105–170 minutes.

When used for dental anesthesia, mepivacaine hydrochloride has an onset of action of about 0.5–2 minutes in the upper jaw and 1–4 minutes in the lower jaw. When used for dental anesthesia, 0.7–1 mL of a 3% mepivacaine hydrochloride solution provides pulpal analgesia of 10–17 minutes duration and soft-tissue anesthesia for approximately 60–100 minutes. Duration of anesthesia of mepivacaine may be prolonged by the addition of levonordefrin 1:20,000 or epinephrine 1:200,000.

After absorption into the blood, 60–85% of mepivacaine has been reported to be bound to plasma proteins. Mepivacaine is metabolized mainly in the liver where it undergoes N-demethylation to produce 2′,6′-pipecoloxylidide and aromatic hydroxylation to produce 1-methyl-4′-hydroxy-2′,6′-pipecoloxylidide and 1-methyl-3′-hydroxy-2′,6′-pipecoloxylidide, both of which undergo conjugation with glucuronic acid. Mepivacaine is excreted in the urine as its metabolites and small amounts (about 5–10%) of unchanged drug. Up to 5% of a dose may be metabolized to carbon dioxide which is eliminated via the lungs. More than 50% of a dose is distributed into bile as metabolites and probably undergoes enterohepatic circulation; only a small percentage of a dose is excreted in feces. Although neonates may have limited ability to metabolize mepivacaine, they are able to eliminate the unchanged drug.

Chemistry and Stability

Chemistry

Mepivacaine hydrochloride is a local anesthetic of the amide type with an intermediate duration of action. Mepivacaine hydrochloride occurs as a white, crystalline solid and is freely soluble in water. The pk_a of mepivacaine hydrochloride has been reported as 7.6 and 7.8. Commercially available solutions of mepivacaine have a pH of 4.5–6.8; pH is adjusted with sodium hydroxide or hydrochloric acid. Multiple-dose vials of mepivacaine hydrochloride injection contain methylparaben as a preservative. Mepivacaine hydrochloride solutions containing levonordefrin (Neo-Cobefrin^®) have a pH of 4.5–6.8; pH is adjusted with sodium hydroxide or hydrochloric acid.

Stability

Mepivacaine hydrochloride injections should be stored at a temperature less than 40°C, preferably between 15–30°C; freezing should be avoided. Mepivacaine hydrochloride 2% with levonordefrin 1:20,000 injection should be stored between 15–30°C.

Mepivacaine hydrochloride solutions are highly resistant to acid or alkaline hydrolysis and can be autoclaved repeatedly or stored for long periods; dental cartridges, however, should not be autoclaved because the closures used in the cartridges will not withstand autoclaving. In addition, the injection containing levonordefrin is not stable to autoclaving. Mepivacaine hydrochloride is incompatible with alkali hydroxides.

For further information on chemistry and stability, pharmacology, pharmacokinetics, uses, cautions, and dosage and administration of mepivacaine hydrochloride, see the Local Anesthetics, Parenteral, General Statement 72:00.

Preparations

Mepivacaine Hydrochloride

Routes	Forms	Strengths	Brand Names	Manufacturer
Parenteral	Injection	1%*	Carbocaine® Hydrochloride (methylparaben-free in single-dose vials or with methylparaben in multiple-dose vials)	Hospira
			Polocaine® (with methylparaben)	AstraZeneca
			Polocaine®-MPF (methylparaben-free)	AstraZeneca
		1.5%	Carbocaine® Hydrochloride (methylparaben-free)	Sanofi
			Polocaine®-MPF (methylparaben-free)	AstraZeneca
		2%*	Carbocaine® Hydrochloride (methylparaben-free in single-dose vials or with methylparaben in multiple-dose vials)	Hospira
			Polocaine® (with methylparaben)	AstraZeneca
			Polocaine®-MPF (methylparaben-free)	AstraZeneca
		3%	Polocaine® (methylparaben-free)	AstraZeneca

* available by nonproprietary name

Mepivacaine Hydrochloride Combinations

Routes	Forms	Strengths	Brand Names	Manufacturer
Parenteral	Injection	2% with Levonordefrin 1:20,000	Polocaine® with Levonordefrin (methylparaben-free; with sodium metabisulfite)	AstraZeneca

Selected Revisions January 2004, © Copyright, January 1974, American Society of Health-System Pharmacists, Inc. 7272 Wisconsin Avenue, Bethesda, MD 20814.