lidocaine/prilocaine

General

Pronunciation
LYE-doe-kane/PRI-loe-kane [Pronunciation]

Trade Name(s)

• EMLA

• Oraqix

Pregnancy Category
Category B

Ther. class.
anesthetics topical local

Indications

• Produces local anesthesia prior to minor painful procedures including:

» Insertion of cannulae or needles,

» Arterial/venous/lumbar puncture,

» Intramuscular injections,

» Subcutaneous injections,

» Dermal procedures,

» Laser treatments,

» Circumcision.

• When applied to genital mucous membranes in preparation for superficial minor surgery or as preparation for infiltration anesthesia.

• Produces localized anesthesia in periodontal pockets during scaling and/or root planing (Oraqix only).

Action

Produces local anesthesia by inhibiting transport of ions across neuronal membranes, thereby preventing initiation and conduction of normal nerve impulses. Combination of two anesthetics is applied as a system consisting of a cream under an occlusive dressing. Active drug is released into the dermal and epidermal skin layers, resulting in accumulation of local anesthetic in the regions of dermal pain receptors and nerve endings.

Therapeutic Effect(s):
Anesthetic action localized to the area of the application.

Pharmacokinetics

Absorption: Small amounts are systemically absorbed.

Distribution: Small amounts absorbed are widely distributed and cross the placenta and blood-brain barrier.

Metabolism and Excretion: Lidocaine—mostly metabolized by the liver. Prilocaine—metabolized by the liver and kidneys.

Half-life: Lidocaine—90–120 min (EMLA); 2–6 hr (Oraqix): Prilocaine—10–50 min (EMLA); 2–6 hr (Oraqix).

TIME/ACTION PROFILE (local anesthesia)

ROUTE	ONSET	PEAK	DURATION
Top	1 hr(EMLA); 30 sec (Oraqix)	3 hr (EMLA)	1–2 hr (EMLA)†; 20 min (Oraqix)

†Following removal of occlusive dressing

Contraindication/Precautions

Contraindicated in:

• Hypersensitivity to lidocaine, prilocaine, or any other amide-type local anesthetic;

• Hypersensitivity to any other product in the formulation;

• Should not be applied to middle ear, mucous membranes, or broken/inflamed skin;

• Pedi: Congenital or idiopathic methemoglobinemia;

• Infants <1 mo if gestational age is <37 weeks;

• Infants <12 mo receiving methemoglobin-inducing agents.

Use Cautiously in:

• Repeated use or use on large areas of skin (more likely to result in systemic absorption);

• Acutely ill, or debilitated patients (↑ risk of absorption and systemic effects);

• Severe liver disease;

• Any conditions associated with methemoglobinemia (including glucose-6-phosphate dehydrogenase deficiency);

• OB: Use only if clearly needed;

• Lactation: Usually compatible with breastfeeding (AAP);

• Pedi: Area/duration of treatment should be limited in neonates and children <20 kg or 37 weeks gestation (↑ susceptibility to methemoglobinemia);

• Geri: May have ↑ absorption and risk of systemic effects.

Adverse Reactions/Side Effects

Local: blanching, redness, alteration in temperature sensation, edema, itching, rash, hyperpigmentation.

Misc: ALLERGIC REACTIONS INCLUDING ANAPHYLAXIS .

*CAPITALS indicates life-threatening.
*italic indicates most frequent.

Interactions

Drug-Drug

• Concurrent use with class I antiarrhythmics including mexiletine may result in adverse cardiovascular effects.

• Concurrent use with other local anesthetics may result in ↑ toxicity.

• Concurrent use with sulfonamides , acetaminophen , chloroquine , nitroglycerin , nitroprusside , phenobarbital , phenytoin , or quinine in children ↑ the risk of methemoglobinemia (avoid concurrent use in children <12 mo).

Route/Dosage

EMLA

• Topical (Adults and Children): Minor dermal procedures including venipuncture and IV cannulation—2.5 g (½ of the 5-g tube) applied to 20–25 cm² (2 in. by 2 in.) area of skin, covered with an occlusive dressing applied for at least 1 hr. Major dermal procedures including split-thickness skin graft harvesting—2 g/10 cm² area of skin, covered with an occlusive dressing for at least 2 hr. Adult male genital skin—as an adjunct prior to local anesthetic infiltration, apply a thick layer (1 g/10 cm²) to skin surface for 15 min; local infiltration anesthesia should be performed immediately after removal of cream. Adult female genital mucous membranes—apply a thick layer (5–log) for 5–10 min..

• Topical (Children 7–12 yr and >20 kg): Dose should not exceed 20 g over more than 200 cm² for more than 4 hr..

• Topical (Children 1–6 yr and >10 kg): Dose should not exceed 10 g over more than 100 cm² for more than 4 hr..

• Topical (Children 3 mo–12 mo and >5 kg): Dose should not exceed 2 g over more than 20 cm² for more than 4 hr..

• Topical (Children 0–3 mo or <5 kg): Dose should not exceed 1 g over more than 10 cm² for more than 1 hr..

Oraqix

• Topical (Adults): Apply on gingival margin around the selected teeth using the blunt-tipped applicator included in package; wait 30 seconds, then fill the periodontal pockets with gel using the blunt-tipped applicator until the gel becomes visible at the gingival margin; wait another 30 seconds before starting treatment; maximum recommended dose at one treatment session is 5 cartridges (8.5 g)..

Availability

• Cream: 2.5% lidocaine with 2.5% prilocaine

• Periodontal gel: 2.5% lidocaine with 2.5% prilocaine; 1.7 g/dental cartridge

Assessment

• Assess application site for open wounds. Apply only to intact skin.

• Assess application site for anesthesia following removal of system and prior to procedure.

Potential Nursing Diagnoses

• Acute pain (Indications)

Implementation

Topical: EMLA: When used for minor dermal procedures (venipuncture, IV cannulation, arterial puncture, lumbar puncture), apply the 2.5-g tube of cream (½ of the 5-g tube) to each 2 in. by 2 in. area of skin in a thick layer at the site of the impending procedure. Remove the center cutout piece from an occlusive dressing (supplied with the 5-g tube) and peel the paper liner from the paper-framed dressing. Cover the lidocaine/prilocaine cream so that there is a thick layer of cream underneath the occlusive dressing. Do not spread out or rub in the cream. Smooth the dressing edges carefully and ensure it is secure to avoid leakage. Remove the paper frame and mark the time of application on the occlusive dressing. Lidocaine/prilocaine cream must be applied at least 1 hr before the start of a minor dermal procedure (venipuncture, IV cannulation). Anesthesia may be more profound with 90 min–2 hr application. Remove the occlusive dressing and wipe off the lidocaine/prilocaine cream. Clean the entire area with antiseptic solution and prepare the patient for the procedure.

» For major dermal procedures (skin graft harvesting), follow the same procedure using larger amounts of lidocaine/prilocaine cream and the appropriate-size occlusive dressing. Lidocaine/prilocaine cream must be applied at least 2 hr before major dermal procedures.

Patient/Family Teaching

• Explain the purpose of cream and occlusive dressing to patient and parents. Inform the patient that lidocaine/prilocaine cream may block all sensations in the treated skin. Caution patient to avoid trauma to the area from scratching, rubbing, or exposure to extreme heat or cold temperatures until all sensation has returned.

• Home Care Issues: Instruct patient or parent in proper application. Provide a diagram of location for application.

Evaluation/Desired Outcomes

Anesthesia in the area of application.