Lidocaine 25 MG/ML / Prilocaine 25 MG/ML Topical Cream
WARNINGS
Application of lidocaine and prilocaine cream to larger areas or for longer times than those recommended could result in sufficient absorption of lidocaine and prilocaine resulting in serious adverse effects (see Individualization of Dose).
Patients treated with class III anti-arrhythmic drugs (e.g., amiodarone, bretylium, sotalol, dofetilide) should be under close surveillance and ECG monitoring considered, because cardiac effects may be additive.
Studies in laboratory animals (guinea pigs) have shown that lidocaine and prilocaine cream has an ototoxic effect when instilled into the middle ear.
In these same studies, animals exposed to lidocaine and prilocaine cream in the external auditory canal only, showed no abnormality.
Lidocaine and prilocaine cream should not be used in any clinical situation when its penetration or migration beyond the tympanic membrane into the middle ear is possible.
Methemoglobinemia: Lidocaine and prilocaine cream should not be used in those rare patients with congenital or idiopathic methemoglobinemia and in infants under the age of twelve months who are receiving treatment with methemoglobin-inducing agents.
Very young patients or patients with glucose-6-phosphate dehydrogenase deficiencies are more susceptible to methemoglobinemia.
Patients taking drugs associated with drug-induced methemoglobinemia such as sulfonamides, acetaminophen, acetanilid, aniline dyes, benzocaine, chloroquine, dapsone, naphthalene, nitrates and nitrites, nitrofurantoin, nitroglycerin, nitroprusside, pamaquine, para-aminosalicylic acid, phenacetin, phenobarbital, phenytoin, primaquine, quinine, are also at greater risk for developing methemoglobinemia.
There have been reports of significant methemoglobinemia (20 to 30%) in infants and children following excessive applications of lidocaine and prilocaine cream.
These cases involved the use of large doses, larger than recommended areas of application, or infants under the age of 3 months who did not have fully mature enzyme systems.
In addition, a few of these cases involved the concomitant administration of methemoglobin-inducing agents.
Most patients recovered spontaneously after removal of the cream.
Treatment with IV methylene blue may be effective if required.
Physicians are cautioned to make sure that parents or other caregivers understand the need for careful application of lidocaine and prilocaine cream, to ensure that the doses and areas of application recommended in TABLE 2 are not exceeded (especially in children under the age of 3 months) and to limit the period of application to the minimum required to achieve the desired anesthesia.
Neonates and infants up to 3 months of age should be monitored for Met-Hb levels before, during, and after the application of lidocaine and prilocaine cream, provided the test results can be obtained quickly.
DRUG INTERACTIONS
Drug Interactions Lidocaine and prilocaine cream should be used with caution in patients receiving Class I antiarrhythmic drugs (such as tocainide and mexiletine) since the toxic effects are additive and potentially synergistic.
Prilocaine may contribute to the formation of methemoglobin in patients treated with other drugs known to cause this condition (see Methemoglobinemia subsection of WARNINGS).
Specific interaction studies with lidocaine/prilocaine and class III anti-arrhythmic drugs (e.g., amiodarone, bretylium, sotalol, dofetilide) have not been performed, but caution is advised (see WARNINGS).
Should lidocaine and prilocaine cream be used concomitantly with other products containing lidocaine and/or prilocaine, cumulative doses from all formulations must be considered.
OVERDOSAGE
Peak blood levels following a 60 g application to 400 cm2 of intact skin for 3 hours are 0.05 to 0.16 mcg/mL for lidocaine and 0.02 to 0.10 mcg/mL for prilocaine.
Toxic levels of lidocaine (>5 mcg/mL) and/or prilocaine (>6 mcg/mL) cause decreases in cardiac output, total peripheral resistance and mean arterial pressure.
These changes may be attributable to direct depressant effects of these local anesthetic agents on the cardiovascular system.
In the absence of massive topical overdose or oral ingestion, evaluation should include evaluation of other etiologies for the clinical effects or overdosage from other sources of lidocaine, prilocaine or other local anesthetics.
Consult the package inserts for parenteral Xylocaine (lidocaine HCl) or Citanest (prilocaine HCl) for further information for the management of overdose.
DESCRIPTION
Lidocaine and prilocaine cream USP, 2.5%/2.5% is an emulsion in which the oil phase is a eutectic mixture of lidocaine and prilocaine in a ratio of 1:1 by weight.
This eutectic mixture has a melting point below room temperature and therefore both local anesthetics exist as a liquid oil rather than as crystals.
It is packaged in 5 gram and 30 gram tubes.
Lidocaine is chemically designated as acetamide, 2-(diethylamino)-N-(2,6-dimethylphenyl), has an octanol: water partition ratio of 43 at pH 7.4, and has the following structure: C14H22N2O M.W.
234.3 Prilocaine is chemically designated as propanamide, N-(2-methylphenyl)-2-(propylamino), has an octanol: water partition ratio of 25 at pH 7.4, and has the following structure: C13H20N2O M.W.
220.3 Each gram of lidocaine and prilocaine cream contains lidocaine 25 mg, prilocaine 25 mg, purified water, PEG-60/hydrogenated castor oil, carbopol 5984 and sodium hydroxide to adjust pH to approximately 9.
Lidocaine and prilocaine cream contains no preservative, however it passes the USP antimicrobial effectiveness test due to the pH.
The specific gravity of lidocaine and prilocaine cream is 1.00.
The therapeutic class is topical anesthetic agent.
a3873b70-figure-01 a3873b70-figure-02
CLINICAL STUDIES
Lidocaine and prilocaine cream application in adults prior to IV cannulation or venipuncture was studied in 200 patients in four clinical studies in Europe.
Application for at least 1 hour provided significantly more dermal analgesia than placebo cream or ethyl chloride.
Lidocaine and prilocaine cream was comparable to subcutaneous lidocaine, but was less efficacious than intradermal lidocaine.
Most patients found lidocaine and prilocaine cream treatment preferable to lidocaine infiltration or ethyl chloride spray.
Lidocaine and prilocaine cream was compared with 0.5% lidocaine infiltration prior to skin graft harvesting in one open label study in 80 adult patients in England.
Application of lidocaine and prilocaine cream for 2 to 5 hours provided dermal analgesia comparable to lidocaine infiltration.
Lidocaine and prilocaine cream application in children was studied in seven non-US studies (320 patients) and one US study (100 patients).
In controlled studies, application of lidocaine and prilocaine cream for at least 1 hour with or without presurgical medication prior to needle insertion provided significantly more pain reduction than placebo.
In children under the age of seven years, lidocaine and prilocaine cream was less effective than in older children or adults.
Lidocaine and prilocaine cream was compared with placebo in the laser treatment of facial port-wine stains in 72 pediatric patients (ages 5-16).
Lidocaine and prilocaine cream was effective in providing pain relief during laser treatment.
Lidocaine and prilocaine cream alone was compared to lidocaine and prilocaine cream followed by lidocaine infiltration and lidocaine infiltration alone prior to cryotherapy for the removal of male genital warts.
The data from 121 patients demonstrated that lidocaine and prilocaine cream was not effective as a sole anesthetic agent in managing the pain from the surgical procedure.
The administration of lidocaine and prilocaine cream prior to lidocaine infiltration provided significant relief of discomfort associated with local anesthetic infiltration and thus was effective in the overall reduction of pain from the procedure only when used in conjunction with local anesthetic infiltration of lidocaine.
Lidocaine and prilocaine cream was studied in 105 full term neonates (gestational age: 37 weeks) for blood drawing and circumcision procedures.
When considering the use of lidocaine and prilocaine cream in neonates, the primary concerns are the systemic absorption of the active ingredients and the subsequent formation of methemoglobin.
In clinical studies performed in neonates, the plasma levels of lidocaine, prilocaine, and methemoglobin were not reported in a range expected to cause clinical symptoms.
Local dermal effects associated with lidocaine and prilocaine cream application in these studies on intact skin included paleness, redness and edema and were transient in nature (see ADVERSE REACTIONS).
The application of lidocaine and prilocaine cream on genital mucous membranes for minor, superficial surgical procedures (e.g., removal of condylomata acuminata) was studied in 80 patients in a placebo-controlled clinical trial (60 patients received lidocaine and prilocaine cream and 20 patients received placebo).
Lidocaine and prilocaine cream (5 to 10 g) applied between 1 and 75 minutes before surgery, with a median time of 15 minutes, provided effective local anesthesia for minor superficial surgical procedures.
The greatest extent of analgesia, as measured by VAS scores, was attained after 5 to 15 minutes’ application.
The application of lidocaine and prilocaine cream to genital mucous membranes as pretreatment for local anesthetic infiltration was studied in a double-blind, placebo-controlled study in 44 female patients (21 patients received lidocaine and prilocaine cream and 23 patients received placebo) scheduled for infiltration prior to a surgical procedure of the external vulva or genital mucosa.
Lidocaine and prilocaine cream applied to the genital mucous membranes for 5 to 10 minutes resulted in adequate topical anesthesia for local anesthetic injection.
Individualization of Dose: The dose of lidocaine and prilocaine cream which provides effective analgesia depends on the duration of the application over the treated area.
All pharmacokinetic and clinical studies employed a thick layer of lidocaine and prilocaine cream (1 to 2 g/10 cm2).
The duration of application prior to venipuncture was 1 hour.
The duration of application prior to taking split thickness skin grafts was 2 hours.
Although a thinner application may be efficacious, such has not been studied and may result in less complete analgesia or a shorter duration of adequate analgesia.
The systemic absorption of lidocaine and prilocaine is a side effect of the desired local effect.
The amount of drug absorbed depends on surface area and duration of application.
The systemic blood levels depend on the amount absorbed and patient size (weight) and rate of systemic drug elimination.
Long duration of application, large treatment area, small patients, or impaired elimination may result in high blood levels.
The systemic blood levels are typically a small fraction (1/20 to 1/36) of the blood levels which produce toxicity.
TABLE 2 which follows gives maximum recommended doses, application areas and application times for infants and children.
TABLE 2 Lidocaine and Prilocaine Cream Maximum Recommended Dose, Application Area, and Application Time by Age and Weight* For Infants and Children Based on Application to Intact Ski n Age and Body Weight Requirements Maximum Total Dose of Lidocaine and Prilocaine Cream Maximum Application Area** Maximum Application Time 0 up to 3 months or 5 kg 2 g 20 cm2 4 hours 1 to 6 years and > 10 kg 10 g 100 cm2 4 hours 7 to 12 years and > 20 kg 20 g 200 cm2 4 hours Please note: If a patient greater than 3 months old does not meet the minimum weight requirement, the maximum total dose of lidocaine and prilocaine cream should be restricted to that which corresponds to the patient’s weight.
*These are broad guidelines for avoiding systemic toxicity in applying lidocaine and prilocaine cream to patients with normal intact skin and with normal renal and hepatic function.
**For more individualized calculation of how much lidocaine and prilocaine may be absorbed, physicians can use the following estimates of lidocaine and prilocaine absorption for children and adults: The estimated mean (±SD) absorption of lidocaine is 0.045 (±0.016) mg/cm2/hr.
The estimated mean (±SD) absorption of prilocaine is 0.077 (±0.036) mg/cm2/hr.
An IV antiarrhythmic dose of lidocaine is 1 mg/kg (70 mg/70 kg) and gives a blood level of about 1 mcg/mL.
Toxicity would be expected at blood levels above 5 mcg/mL.
Smaller areas of treatment are recommended in a debilitated patient, a small child or a patient with impaired elimination.
Decreasing the duration of application is likely to decrease the analgesic effect.
HOW SUPPLIED
Product: 50090-2167 NDC: 50090-2167-0 30 g in a TUBE
GERIATRIC USE
Geriatric Use Of the total number of patients in clinical studies of lidocaine and prilocaine cream, 180 were age 65 to 74 and 138 were 75 and over.
No overall differences in safety or efficacy were observed between these patients and younger patients.
Other reported clinical experience has not identified differences in responses between the elderly and younger patients, but greater sensitivity of some older individuals cannot be ruled out.
Plasma levels of lidocaine and prilocaine in geriatric and non-geriatric patients following application of a thick layer of lidocaine and prilocaine cream are very low and well below potentially toxic levels.
However, there are no sufficient data to evaluate quantitative differences in systemic plasma levels of lidocaine and prilocaine between geriatric and non-geriatric patients following application of lidocaine and prilocaine cream.
Consideration should be given for those elderly patients who have enhanced sensitivity to systemic absorption.
(See PRECAUTIONS.) After intravenous dosing, the elimination half-life of lidocaine is significantly longer in elderly patients (2.5 hours) than in younger patients (1.5 hours).
(See CLINICAL PHARMACOLOGY.)
INDICATIONS AND USAGE
Lidocaine and prilocaine cream USP, 2.5%/2.5% (a eutectic mixture of lidocaine 2.5% and prilocaine 2.5%) is indicated as a topical anesthetic for use on: • normal intact skin for local analgesia.
• genital mucous membranes for superficial minor surgery and as pretreatment for infiltration anesthesia.
Lidocaine and prilocaine cream is not recommended in any clinical situation in which penetration or migration beyond the tympanic membrane into the middle ear is possible because of the ototoxic effects observed in animal studies (see WARNINGS).
PEDIATRIC USE
Pediatric Use Controlled studies of lidocaine and prilocaine cream in children under the age of seven years have shown less overall benefit than in older children or adults.
These results illustrate the importance of emotional and psychological support of younger children undergoing medical or surgical procedures.
Lidocaine and prilocaine cream should be used with care in patients with conditions or therapy associated with methemoglobinemia (see Methemoglobinemia subsection of WARNINGS).
When using lidocaine and prilocaine cream in young children, especially infants under the age of 3 months, care must be taken to insure that the caregiver understands the need to limit the dose and area of application, and to prevent accidental ingestion (see DOSAGE AND ADMINISTRATION and Methemoglobinemia).
In neonates (minimum gestation: 37 weeks) and children weighing less than 20 kg, the area and duration of application should be limited (see TABLE 2 in Individualization of Dose).
Studies have not demonstrated the efficacy of lidocaine and prilocaine cream for heel lancing in neonates.
NUSRING MOTHERS
Nursing Mothers Lidocaine, and probably prilocaine, are excreted in human milk.
Therefore, caution should be exercised when lidocaine and prilocaine cream is administered to a nursing mother since the milk: plasma ratio of lidocaine is 0.4 and is not determined for prilocaine.
INFORMATION FOR PATIENTS
Information for Patients When lidocaine and prilocaine cream is used, the patient should be aware that the production of dermal analgesia may be accompanied by the block of all sensations in the treated skin.
For this reason, the patient should avoid inadvertent trauma to the treated area by scratching, rubbing, or exposure to extreme hot or cold temperatures until complete sensation has returned.
Lidocaine and prilocaine cream should not be applied near the eyes or on open wounds.
DOSAGE AND ADMINISTRATION
Adult Patients-Intact Skin: A thick layer of lidocaine and prilocaine cream is applied to intact skin and covered with an occlusive dressing (see INSTRUCTIONS FOR APPLICATION).
Minor Dermal Procedures: For minor procedures such as intravenous cannulation and venipuncture, apply 2.5 grams of lidocaine and prilocaine cream (1/2 the 5 g tube) over 20 to 25 cm2 of skin surface for at least 1 hour.
In controlled clinical trials using lidocaine and prilocaine cream, two sites were usually prepared in case there was a technical problem with cannulation or venipuncture at the first site.
Major Dermal Procedures: For more painful dermatological procedures involving a larger skin area such as split thickness skin graft harvesting, apply 2 grams of lidocaine and prilocaine cream per 10 cm2 of skin and allow to remain in contact with the skin for at least 2 hours.
Adult Male Genital Skin: As an adjunct prior to local anesthetic infiltration, apply a thick layer of lidocaine and prilocaine cream (1 g/10 cm2) to the skin surface for 15 minutes.
Local anesthetic infiltration should be performed immediately after removal of lidocaine and prilocaine cream.
Dermal analgesia can be expected to increase for up to 3 hours under occlusive dressing and persist for 1 to 2 hours after removal of the cream.
The amount of lidocaine and prilocaine absorbed during the period of application can be estimated from the information in TABLE 2, ** footnote, in Individualization of Dose.
Adult Female Patients-Genital Mucous Membranes: For minor procedures on the female external genitalia, such as removal of condylomata acuminata, as well as for use as pretreatment for anesthetic infiltration, apply a thick layer (5 to 10 grams) of lidocaine and prilocaine cream for 5 to 10 minutes.
Occlusion is not necessary for absorption, but may be helpful to keep the cream in place.
Patients should be lying down during the lidocaine and prilocaine cream application, especially if no occlusion is used.
The procedure or the local anesthetic infiltration should be performed immediately after the removal of lidocaine and prilocaine cream.
Pediatric Patients-Intact Skin: The following are the maximum recommended doses, application areas and application times for lidocaine and prilocaine cream based on a child’s age and weight: Age and Body Weight Requirements Maximum Total Dose of Lidocaine and Prilocaine Cream Maximum Application Area Maximum Application Time 0 up to 3 months or 5 kg 2 g 20 cm2 4 hours 1 to 6 years and > 10 kg 10 g 100 cm2 4 hours 7 to 12 years and > 20 kg 20 g 200 cm2 4 hours Please note: If a patient greater than 3 months old does not meet the minimum weight requirement, the maximum total dose of lidocaine and prilocaine cream should be restricted to that which corresponds to the patient’s weight (see INSTRUCTIONS FOR APPLICATION).
Practitioners should carefully instruct caregivers to avoid application of excessive amounts of lidocaine and prilocaine cream (see PRECAUTIONS).
When applying lidocaine and prilocaine cream to the skin of young children, care must be taken to maintain careful observation of the child to prevent accidental ingestion of lidocaine and prilocaine cream, or the occlusive dressing.
A secondary protective covering to prevent inadvertent disruption of the application site may be useful.
Lidocaine and prilocaine cream should not be used in neonates with a gestational age less than 37 weeks nor in infants under the age of twelve months who are receiving treatment with methemoglobin-inducing agents (see Methemoglobinemia subsection of WARNINGS).
When lidocaine and prilocaine cream is used concomitantly with other products containing local anesthetic agents, the amount absorbed from all formulations must be considered (see Individualization of Dose).
The amount absorbed in the case of lidocaine and prilocaine cream is determined by the area over which it is applied and the duration of application under occlusion (see TABLE 2, ** footnote, in Individualization of Dose).
Although the incidence of systemic adverse reactions with lidocaine and prilocaine cream is very low, caution should be exercised, particularly when applying it over large areas and leaving it on for longer than 2 hours.
The incidence of systemic adverse reactions can be expected to be directly proportional to the area and time of exposure (see Individualization of Dose).
INSTRUCTIONS FOR APPLICATION To measure 1 gram of lidocaine and prilocaine cream, the cream should be gently squeezed out of the tube as a narrow strip that is 1.5 inches (3.8 cm) long and 0.2 inches (5 mm) wide.
The strip of lidocaine and prilocaine cream should be contained within the lines of the diagram shown below.
≈ 1 g strip 1.5 x 0.2 inches Use the number of strips that equals your dose, like the examples in the table below.
Dosing Information 1 gram = 1 strip 2 grams = 2 strips 2.5 grams = 2.5 strips For adult and pediatric patients, apply ONLY as prescribed by your physician.
If your child is below the age of 3 months or small for their age, please inform your doctor before applying lidocaine and prilocaine cream, which can be harmful, if applied over too much skin at one time in young children.
When applying lidocaine and prilocaine cream to the intact skin of young children, it is important that they be carefully observed by an adult in order to prevent the accidental ingestion of or eye contact with lidocaine and prilocaine cream.
Lidocaine and prilocaine cream must be applied to intact skin at least 1 hour before the start of a routine procedure and for 2 hours before the start of a painful procedure.
A protective covering of the cream is not necessary for absorption but may be helpful to keep the cream in place.
If using a protective covering, your doctor will remove it, wipe off the lidocaine and prilocaine cream, and clean the entire area with an antiseptic solution before the procedure.
The duration of effective skin anesthesia will be at least 1 hour after removal of the protective covering.
PRECAUTIONS: 1.
Do not apply near eyes or on open wounds.
2.
Keep out of reach of children.
3.
If your child becomes very dizzy, excessively sleepy, or develops duskiness of the face or lips after applying lidocaine and prilocaine cream, remove the cream and contact your physician at once.
Call your doctor for medical advice about side effects.
You may report side effects to FDA at 1-800-FDA-1088.