Lidocaine + Prilocaine topical

Indications

Lidocaine + Prilocaine topical is used for: Local anaesthesia

Adult Dose

Topical Dermal Procedures Minor dermatological procedures (e.g. IV cannulation or venipuncture): 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

Child Dose

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

Renal Dose

Administration

Apply a thick layer to intact skin and cover with occlusive dressing. 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

Contra Indications

Neonates with gestational age <37 wk. Infants <12 mth of age who are receiving treatment with methaemoglobin-inducing agents or children who are receiving medications associated with drug-induced methaemoglobinemia. Children with congenital or idiopathic methaemoglobinemia. Application on mucous membranes, broken or inflamed skin.

Precautions

Caution when used over large areas and leaving on for >2 hr. Severe hepatic impairment. Caution when used in patients who are receiving class I and III antiarrhythmics. Dose reduction may be necessary in acutely ill, debilitated patients and elderly. Avoid using on open wounds or near the eyes. Pregnancy and lactation. Lactation: Excreted in breast milk; use not recommended

Pregnancy-Lactation

Pregnancy Category: B Lactation: Excreted in breast milk; use not recommended

Interactions

Increased risk of toxicity when used with drugs that are known to cause methaemoglobinaemia. Concurrent use with class III antiarrhythmics may lead to additive cardiac effects. Toxic effects may be additive when used with class I antiarrhythmics.

Adverse Effects

Side effects of Lidocaine + Prilocaine topical : >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)

Mechanism of Action

Lidocaine and prilocaine are local anaesthetic agents of the amide type. Both work by stabilising the neuronal membranes and inhibiting the ionic fluxes required for the initiation and conduction of impulses, thereby giving rise to the anaesthetic action.