Lidocaine/Prilocaine Aguettant (Lidocaine, Prilocaine)

Lidocaine/Prilocaine is a local anesthetic used on the skin and mucous membranes to achieve temporary loss of sensation.

• Minor skin procedures: provides rapid surface anesthesia for biopsies, suturing or laser treatment.
• Mucous membrane anesthesia: numbs oral, nasal or genital mucosa during diagnostic or therapeutic procedures.
• Superficial wound or burn pain relief: reduces pain and discomfort from shallow injuries or first‑degree burns.

• Lidocaine and prilocaine reversibly block voltage‑gated sodium channels in peripheral nerve membranes, preventing the initiation and propagation of action potentials. This inhibition stops the transmission of pain signals from the site of application, resulting in localized loss of sensation without affecting central nervous system function when used as directed.

Adverse reactions are generally limited to the application site, but systemic absorption can produce rare serious events.

Common Side Effects

• Mild skin irritation or erythema
• Itching or burning sensation at the site
• Localized edema or swelling
• Allergic contact dermatitis
• Transient numbness lasting longer than expected
• Dryness or peeling of the treated skin

Serious or Rare Side Effects

• Systemic toxicity (e.g., dizziness, seizures, CNS depression)
• Methemoglobinemia leading to cyanosis
• Severe allergic reaction or anaphylaxis
• Cardiac arrhythmias or conduction disturbances
• Persistent numbness or paresthesia
• Tissue necrosis with prolonged occlusive use

Before applying Lidocaine/Prilocaine, consider patient history and proper usage to minimise risk.

• Allergy assessment: confirm no known hypersensitivity to amide‑type local anesthetics.
• Application area: avoid use on broken, infected or inflamed skin unless directed.
• Surface area limit: restrict total treated area to the amount recommended by the prescriber.
• Patient monitoring: observe for signs of systemic toxicity, especially in children or the elderly.
• Special populations: use with caution in infants, pregnant or lactating women when benefits outweigh risks.
• Store at room temperature: keep in the original container, protect from moisture and direct sunlight.

Lidocaine/Prilocaine may interact with other agents that affect sodium channels or metabolic pathways.

Major Interactions (Avoid)

• Concurrent use of other amide‑type local anesthetics (risk of cumulative toxicity).
• Class I antiarrhythmic drugs such as quinidine or procainamide (enhanced cardiac effects).
• High‑dose epinephrine formulations (increased systemic absorption).

Moderate Interactions (Monitor Closely)

• Strong CYP3A4 inhibitors (e.g., erythromycin, ketoconazole) that may raise plasma levels.
• Methemoglobin‑inducing agents such as dapsone or nitrites (additive risk of methemoglobinemia).
• Other medications that lower seizure threshold (e.g., tramadol, bupropion).