Dosing and uses of EMLA, Oraqix (lidocaine-prilocaine)
Adult dosage forms and strengths
lidocaine/prilocaine
cream (EMLA)
- (2.5%/2.5%)/30g
dental gel (Oraqix)
- 2.5%/2.5%
Dermal Procedures
Minor dermatological procedures
- Cream: Apply 2.5 g over 20-25 cm² of skin surface area for at least 1 hr
Painful dermatological procedures involving large areas (eg, split thickness skin graft harvesting)
- Cream: Apply 2 g/10 cm² of skin and allow to remain in contact with the skin for at least 2 hr
- Analgesia is achieved in 1 hr, reaches maximum in 2-3 hr, and persists 1-2 hr after removal
Topical Anesthetic on Genital Mucous Membranes
Superficial minor surgery on male genitalia and as pretreatment for infiltration anesthesia
- Cream: Apply 1 g/10 cm² of skin for 15 min
Minor procedures on the female external genitalia (eg, condylomata acuminata) as well as for use as pretreatment for anesthetic infiltration
- Cream: Apply 5-10 g for 5-10 min
Dental Procedures
Localized anesthesia in periodontal pockets during scaling and/or root planing
Dental gel: Apply one cartridge or less for one quadrant of dentition; do not exceed 5 cartridges per treatment session
Dosing Considerations
Cream
- Gently squeeze cream out of the tube as a narrow strip that is 1.5 inches long and 0.2 inches wide; 1 strip corresponds to 1 g
- Perform local anesthetic infiltration immediately after removal of cream
- Male genital skin: Analgesia will increase up to 3 hours under occlusive dressing and persist 1-2 hours after cream removal
- Female genital skin: Occlusive dressing is not necessary but will keep cream in place
Dental geL
- Anesthetic effect lasts approximately 20 minute; if effect wears off, reapply if needed; one cartridge or less is sufficient for one quadrant of dentition
Administration
Cream
- Apply a thick layer to intact skin and cover with occlusive dressing
- Female genital skin: Patient should be lying down during administration, especially if no occlusion is used
Dental geL
- Do not inject; only use product with blunt-tipped applicator
- Apply on gingival margin around selected teeth using the blunt‐tipped applicator included in package; wait 30 seconds, and fill the periodontal pockets with gel using the blunt‐tipped applicator until it becomes visible at the gingival margin; wait another 30 seconds before starting treatment
- If a gel has formed, place in refrigerator (do not freeze) until it becomes a liquid again; only administer when it is a liquid
Other Indications & Uses
Provides dermal analgesia through intact skin by release of local anesthetics through epidermis
Pediatric dosage forms and strengths
lidocaine/prilocaine
cream (EMLA)
- (2.5%/2.5%)/30g
dental gel (Oraqix)
- 2.5%/2.5%
Local Anesthetic Procedures
Cream
- Neonates (gestation age <37 weeks): Use not recommended
- <12 months: Do not use if receiving treatment with methemoglobinemia-inducing agents
- 0-3 months (or <5 kg): Do not exceed 1 g total dose/application area > 10 cm²/>1 hr application time
- 3-12 months (and >5 kg): Do not exceed 2 g total dose/application area > 20 cm²/>4 hr application time
- 1-6 years (and >10 kg): Do not exceed 10 g total dose/application area > 100 cm²/>4 hr application time
- 7-12 years (and >20 kg): Do not exceed 20 g total dose/application area > 200 cm²/>4 hr application time
Dosing Considerations
Cream
- If patient >3 months does not meet minimum weight requirement, total dose should correspond to patient’s weight
- Care must be taken to avoid accidental ingestion of cream; use secondary protective covering to present disruption of application site
EMLA, Oraqix (lidocaine-prilocaine) adverse (side) effects
>10%
Pallor/blanching (37%)
Application site erythema/pain (30%)
Genital mucous membrane burning sensation (17%)
Oral cavity, periodontal formulation (15%)
1-10%
Alterations in temperature sensations (7%)
Application site edema (6-10%)
Itching (2%)
<1%
Rash
Myocardial dysfunction (rare)
Methemoglobinemia (rare)
Depression/excitation (rare)
Seizure (rare)
Frequency not defined
Localized discrete purpuric or petechial reactions (rare)
Localized hyperpigmentation (rare)
Allergic reactions (eg, urticaria, angioedema, bronchospasm, shock)
Warnings
Contraindications
Hypersensitivity to components, amide-type local anesthetics
Cautions
Do not apply on open wounds
Monitor child closely after administration; if child becomes very dizzy, excessively sleepy, or develops duskiness of the face or lips, remove cream immediately
Exercise caution when applying over large areas for >2 hours due to risk of systemic absorption and adverse effects
Monitor patients treated with class III anti-arrhythmic drugs (eg, amiodarone, bretylium, sotalol, dofetilide) due to additive cardiac effects; consider ECG monitoring
Use of cream is not recommended in any clinical situation when penetration or migration beyond tympanic membrane into middle ear is possible due to ototoxic effects observed in animal studies
Avoid in patients with congenital/idiopathic methemoglobinemia, infants <12 months receiving treatment with methemoglobin-inducing agents, patients on drugs associated with drug-induced methemoglobinemia; monitor Met-Hb levels before, during and after application in patients <3 months; treatment with IV methylene blue may be effective
Monitor acutely ill, debilitated, or elderly patients closely if administering repeated doses
Do not apply near eyes as loss of protective reflexes can permit corneal irritation and potential abrasion
Patients with history of drug sensitivities (eg, allergy to paraaminobenzoic acid derivatives)
Severe hepatic disease due to increased risk of toxic plasma concentrations of lidocaine/prilocaine
Lidocaine and prilocaine have been shown to inhibit viral and bacterial growth
Instruct patient to avoid irritating or exposing treated area to extreme temperatures until complete sensation has returned
Pregnancy and lactation
Pregnancy category: B
Lactation: Excreted in breast milk; use not recommended
Pregnancy categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.
C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.
D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.
X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.
NA: Information not available.
Pharmacology of EMLA, Oraqix (lidocaine-prilocaine)
Mechanism of action
Amide-type local anesthetics stabilize neuronal membranes and prevent generation/conduction of nerve impulses by reducing sodium permeability and increasing action potential threshold
Absorption
Positively correlated to degree of systemic absorption
Peak plasma concentrations: 148-641 ng/mL (lidocaine); 40-346 ng/mL (prilocaine)
Distribution
Vd (IV administration): 1.1-2.1 L/kg (lidocaine); 0.7-4.4 L/kg (prilocaine)
Protein bound: 70% (lidocaine); 55% (prilocaine)
Metabolism
Unknown if metabolized in skin
Systemic metabolism: hepatic (lidocaine); hepatic/renal (prilocaine)
Metabolites: ester- and amide-type local anesthetics
Elimination
t1/2 (IV administration): 65-150 min (lidocaine); 10-150 min (prilocaine)
Excretion (IV administration): Urine (98%) [lidocaine]
