Emla

Emla is a topical anesthetic cream that is used to numb the skin before certain medical procedures, such as injections, venipuncture, and minor skin surgery. The cream is a combination of two active ingredients, lidocaine and prilocaine, which work by temporarily blocking the pathway of pain signals along nerves. Emla is applied directly to the skin and is often used in both adults and children to reduce the pain associated with needle procedures.

Composition

Emla cream contains two local anesthetics, lidocaine (2.5%) and prilocaine (2.5%). These active ingredients are both amide type local anesthetics, which provide a numbing effect by inhibiting sodium channels on the nerve cells' membranes, preventing the initiation and conduction of nerve impulses.

Indications

Emla is indicated for use on intact skin in adults, adolescents, and children to provide topical anesthesia for:

• Preparing for needle insertion (e.g., blood sampling, vaccination)
• Superficial surgical procedures
• Laser treatment of port-wine stains
• Split skin grafting (preparation and harvesting sites)

It is also used to numb the genital skin before minor surgical procedures or before the injection of local anesthetics.

Application

The cream should be applied to the skin in a thick layer without rubbing, covered with an occlusive dressing, and left in place for at least one hour before the medical procedure. The duration of effective skin anesthesia will vary depending on the application site and the procedure involved.

Side Effects

Common side effects of Emla include temporary redness, swelling, or a pale appearance of the skin at the application site. Less commonly, patients may experience itching or a mild burning sensation. Serious side effects are rare but can include allergic reactions to the active ingredients.

Precautions

Emla should not be used on open wounds or on mucous membranes. Caution is advised when using Emla on individuals with a history of methemoglobinemia, a condition related to the use of local anesthetics. It is also important to use the correct dose according to the patient's age and weight, especially in children, to avoid systemic toxicity.

Pharmacology

Lidocaine and prilocaine, the active components of Emla, are both absorbed through the skin to provide local anesthesia. The combination of these two anesthetics allows for a synergistic effect, enhancing the depth and duration of anesthesia with minimal systemic absorption.

History

Emla was developed as a means to reduce the pain associated with needle procedures and minor surgeries without the need for injectable anesthetics. It was one of the first topical anesthetic creams to combine lidocaine and prilocaine, offering a non-invasive alternative for pain management in various medical settings.