Lidocaine Hydrochloride / Prilocaine

Pronunciation: (LIE-doe-cane HIGH-droe-KLOR-ide/PRILL-oh-cane)
Class: Local anesthetic, Topical

Trade Names

EMLA
- Cream 2.5% lidocaine and 2.5% prilocaine
- Anesthetic Disc 1 g EMLA emulsion (2.5% lidocaine, 2.5% prilocaine). Contact surface approximately 10 cm ²

EMLA Patch (Canada)

Pharmacology

Stabilizes neuronal membranes by inhibiting the ionic fluxes required for the initiation and conduction of impulses, thereby effecting local anesthetic action.

Indications and Usage

As a topical anesthetic for use on normal intact skin for local analgesia or genital mucous membranes for superficial minor surgery and as pretreatment for infiltration anesthesia.

Contraindications

Sensitivity to local anesthetics of the amide type or any component of the product.

Dosage and Administration

Minor Dermal Procedures
Adults

Topical Apply 2.5 g of cream over 20 to 25 cm ² of skin surface or 1 anesthetic disc (1 g over 10 cm ² ) for at least 1 h.

Major Dermal Procedures
Adults

Topical Apply 2 g of the cream per 10 cm ² of skin surface and allow to remain in contact with skin for at least 2 h.

Male Genital Skin
Adults

Topical As adjunct prior to local anesthetic infiltration, apply a thick layer of cream (1 g/10 cm ² ) to the skin surface for 15 min. Perform local anesthetic infiltration immediately after removal of the cream.

Female Genital Mucous Membranes
Adults

Topical Apply a thick layer (5 to 10 g) of cream for 5 to 10 min.

Pediatrics (Intact skin)
Children (0 to 3 mo or less than 5 kg)

Topical Apply 1 g per 10 cm ² for a max of 1 h.

Children (3 mo up to 12 mo and more than 5 kg)

Topical Apply 2 g per 20 cm ² for a max of 4 h.

Children (1 yr to 6 yr and more than 10 kg)

Topical Apply 10 g per 100 cm ² for a max of 4 h.

Children (7 yr to 12 yr and more than 20 kg)

Topical Apply 20 g per 200 cm ² for a max of 4 h.

Note

If a patient is older than 3 mo and does not meet the min weight requirement, the max total dose should be restricted to that which corresponds to the patient's weight.

General Advice

• For topical use only. Not for ophthalmic or otic use.
• Dermal analgesia can be expected to increase for up to 3 h under occlusive dressing and persist for 1 to 2 h after removal of the cream.

Storage/Stability

Store at controlled room temperature (59° to 86°F). Keep tube tightly closed.

Drug Interactions

Class I antiarrhythmic agents (eg, mexiletine, tocainide)

Toxic effects may be additive or synergistic.

Methemoglobin-inducing agents

May increase risk of methemoglobinemia.

Laboratory Test Interactions

None well documented.

Adverse Reactions

Cardiovascular

Bradycardia; hypotension, CV collapse leading to arrest.

CNS

CNS excitement or depression; lightheadedness; nervousness; apprehension; euphoria; confusion; dizziness; drowsiness; sensations of hot, cold, or numbness; twitching; tremors; convulsions, unconsciousness; respiratory depression and arrest.

Dermatologic

Paleness (37%); erythema (30%); burning sensation (17%); edema (10%); alterations in temperature sensations (7%); itching (2%); discrete purpuric or petechial reactions at the site of application; hyperpigmentation (cream); redness; blistering of foreskin in neonates about to undergo circumcision.

EENT

Tinnitus; blurred or double vision.

GI

Vomiting.

Miscellaneous

Allergic and anaphylactoid reactions (characterized by urticaria, angioedema, bronchospasm, and shock).

Precautions

Pregnancy

Category B .

Lactation

Lidocaine and probably prilocaine are excreted in human milk.

Children

Children under 7 yr have shown less overall benefit than older children or adults. Do not use in neonates with a gestational age of 37 wk or less.

Application

Application to larger areas or for longer than recommended could result in sufficient absorption causing serious adverse reactions.

Methemoglobinemia

Do not use in patients with congenital or idiopathic methemoglobinemia or in infants under 12 mo of age who are receiving treatment with methemoglobin-inducing agents (eg, acetaminophen, nitrates, phenytoin, sulfonamides).

Overdosage

Symptoms

Confusion, drowsiness, unconsciousness, tremors, convulsions, hypotension, bradycardia, CV collapse, cardiac arrest, tinnitus, diplopia.

Patient Information

• Review the patient information leaflet, including instructions for administration, with patient, parent, or guardian.
• Review prescribed dosing schedule with patient, parent, or guardian.
• Caution parent or guardian to not exceed prescribed dose, area of application, nor duration of application when using in infants and young children.
• Caution patient, parent, or guardian that medication may block all skin sensations and to avoid trauma to the treated area by scratching, rubbing, or exposure to extreme hot or cold temperatures until complete sensation has returned.
• Caution patient, parent, or guardian not to apply near eyes or on open wounds.
• Advise patient, parent, or guardian to remove cream and contact health care provider immediately if any of the following occur following application of cream: dizziness; excessive sleepiness; bluish discoloration of face or lips; agitation; twitching; tremors; serious reaction at application site.

Copyright © 2009 Wolters Kluwer Health.