lidocaine/prilocaine (Rx)

>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)

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

Monitor acutely ill, debilitated, or elderly patients closely if administering repeated doses

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

Allergic and anaphylactic reactions associated with lidocaine or prilocaine can occur; these reactions may be characterized by urticaria, angioedema, bronchospasm, and shock; if reactions occur, they should be managed by conventional means

Not to be used with standard dental syringes; only use with blunt‐tipped applicator and dispenser which is available from DENTSPLY Pharmaceutical

Drug coming in contact with the eye should be avoided; animal studies have demonstrated severe eye irritation; a loss of protective reflexes may allow corneal irritation and potential abrasion; if eye contact occurs, immediately rinse eye with water or saline and protect it until normal sensation returns. In addition, the patient should be evaluated by an ophthalmologist, as indicated

Patients with severe hepatic disease, because of their inability to metabolize local anesthetics normally, are at greater risk of developing toxic plasma concentrations of lidocaine and prilocaine

Methemoglobinemia

• Cases of methemoglobinemia reported in association with local anesthetic use; although all patients are at risk for methemoglobinemia, patients with glucose‐6‐phosphate dehydrogenase deficiency, congenital or idiopathic methemoglobinemia, cardiac or pulmonary compromise, infants under 6 months of age, and concurrent exposure to oxidizing agents or their metabolites are more susceptible to developing clinical manifestations of the condition
• If local anesthetics must be used in these patients, close monitoring for symptoms and signs of methemoglobinemia is recommended; signs of methemoglobinemia may occur immediately or may be delayed some hours after exposure, and are characterized by a cyanotic skin discoloration and/or abnormal coloration of the blood
• Methemoglobin levels may continue to rise; therefore, immediate treatment required to avert more serious central nervous system and cardiovascular adverse effects, including seizures, coma, arrhythmias, and death
• Discontinue therapy and any other oxidizing agents; depending on severity of signs and symptoms, patients may respond to supportive care, ie, oxygen therapy, hydration; a more severe clinical presentation may require treatment with methylene blue, exchange transfusion, or hyperbaric oxygen.

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.

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]