Lidocaine and tetracaine is a local (topical) anesthetic drug combination. It is applied topically to numb the area before a local procedure is performed.

Lidocaine and tetracaine Uses:

• Topical Anesthesia:

  • Cream:

    • When applied to adult skin that is still intact, this medication gives adults topical local analgesia for superficial dermatological operations such dermal filler injection, pulsed dye laser therapy, facial laser resurfacing, and laser-assisted tattoo removal.

  • Patch:

    • When applied to intact skin, it provides local analgesia for superficial dermatological treatments such as the excision, electrodesiccation, and shave biopsy of skin lesions in patients under the age of three.

Lidocaine and tetracaine Dose in Adults:

Lidocaine and tetracaine Dose as a topical anesthetic:

• Cream:

  • Superficial dermatological procedures:

    • Prior to the operation, should be applied to healthy skin for 20 to 60 minutes.
      The surface area that needs to be treated determines how much cream is needed; for further information, see the manufacturer's labelling.

• Patch:

  • Venipuncture or intravenous cannulation:

    • Prior to the operation, it should be applied to healthy skin for 20 to 30 minutes.

Note: After removing the previous patch, another patch at a new location may be used to facilitate venous access after a failed attempt.

• • Superficial dermatological procedures:

    • Should be administered for 30 minutes before the treatment to healthy skin.

Lidocaine and tetracaine Dose in Children:

Lidocaine and tetracaine Dose as a topical anesthetic:

• Children ≥3 years and Adolescents: Patch:

  • Venipuncture or IV cannulation:

    • Prior to the operation, it should be applied to healthy skin for 20 to 30 minutes.
    • Note: After removing the previous patch, another patch at a new location may be used to facilitate venous access after a failed attempt. Otherwise, it is not recommended to apply multiple patches in a simultaneous or sequential way.

  • Superficial dermatologic procedures:

    • Should be administered for 30 minutes before the treatment to healthy skin.

Pregnancy Risk Category: B

• Topical application has a lower rate of systemic absorption than parenteral administration. This is determined by the time of application and the surface area.
• After systemic absorption, tetracaine and licoaine cross the placenta to reach the fetus.
• Lidocaine Systemic, Topical and Tetracaine Systemic monographs.

Use of tetracaine and lidocaine during lactation

• Breast milk contains lidocaine, which is secreted in breastmilk. However, it is unknown if breast milk contains tetracaine.
• The amount of lidocaine found in breast milk after topical application is not known.
• Topical application has a lower rate of systemic absorption than parenteral administration. This is determined by the time of application and the surface area.
• To avoid direct exposure to the infant breastfeeding, do not apply to the nipple and surrounding breast area.
• According to the manufacturer, breastfeeding should be considered during therapy. This decision should take into account the risks of infant exposure as well as the benefits to the mother.
• Lidocaine Systemic, Topical and Tetracaine Systemic monographs.

Dose in Kidney Disease:

• No dosage adjustments provided in the manufacturer's labeling.
• Lidocaine is primarily metabolized in the liver and its pharmacokinetics are not expected to be significantly affected after topical administration of recommended doses in patients with renal impairment.

Dose in Liver disease:

No dosage adjustments provided in the manufacturer's labeling (has not been studied). Use cautiously in severe hepatic dysfunction.

Common Side Effects of Lidocaine and tetracaine:

• Cardiovascular:

  • Localized blanching

• Dermatologic:

  • Erythema

• Local:

  • Skin edema

Less Common Side Effects of Lidocaine and tetracaine:

• Central Nervous System:

  • Dizziness
  • Drowsiness
  • Headache
  • Paresthesia

• Dermatologic:

  • Acne Vulgaris
  • Contact Dermatitis
  • Ecchymosis
  • Maculopapular Rash
  • Skin Blister
  • Urticaria
  • Vesicobullous Dermatitis
  • Xeroderma

• Gastrointestinal:

  • Nausea
  • Vomiting

• Hematologic & Oncologic:

  • Petechial Rash

• Hypersensitivity:

  • Hypersensitivity Reaction

• Infection:

  • Infection

• Local:

  • Application-Site Dermatitis
  • Application Site Rash
  • Local Discoloration
  • Application Site Pain
  • Application-Site Pruritus

Contraindications to Lidocaine and tetracaine:

• Hypersensitivity to lidocaine or tetracaine, amide, ester-type or amide anesthetic agents or paraaminobenzoic acids (PABA) or any other component in the formulation

Canadian labeling: Additional contraindications not in US labeling Cream

• Congenital and idiopathic methemoglobinemia
• Procedures that require large amounts of blood over large areas (>400 cm2).

Warnings and precautions

• Methemoglobinemia:

  • Methemoglobinemia can be caused by local anesthetics. It can happen immediately after exposure or later.
  • Strict monitoring is necessary since the risk is higher in patients under the age of six months, those with glucose-6-phosphate dehydrogenase deficiencies, congenital or idiopathic methemoglobinemia, cardiac or pulmonary impairment, or exposure to oxidising agents or their metabolites.
  • If there are clinical signs or symptoms, it is important to stop therapy immediately and get the necessary treatment.

• Hepatic impairment

  • In severe hepatic impairment, use caution

Lidocaine and tetracaine: Drug Interaction

Monitoring parameters:

• Effectiveness of anesthesia

How to administer Lidocaine and tetracaine?

Topical cream

• It should only be used on intact, healthy skin. Avoid contact with eyes or lips.
• Spread self-occluding crème thinly and evenly (approximately 1%) on the treatment area. Use a flat-surfaced instrument (e.g., metal spatula or tongue depressor) to do this. 
• When the moment is right, apply the cream, and when it's time to take it off, grab the free edge with your fingers and pull it away from the skin.
• You can also remove the cream using gauze. After the procedure is complete, the cream should not be applied to the area. 
• If the cream causes irritation to the skin or a burning sensation, you should immediately stop using it. 
• After handling cream, it is important to wash your hands. You should dispose of any cream that has been used.

Transdermal patch

• The patch should be applied to healthy, intact skin and used immediately after opening its pouch. 
• Once the pouch was removed, the patch began to heat up. You can raise the skin temperature by 5 degrees Celsius, but not more than 40 degrees Celsius.
• If the patch causes irritation or a burning sensation, it should be removed. After applying the patch, it is important to wash your hands. The top cover and patch should not ever be removed.
• You should not cover the holes at the top of the patch. The used patches should not be covered with lidocaine or tetracaine. After use, fold adhesive together.

Mechanism of action of Lidocaine and tetracaine:

Stabilizes neuronal membranes and inhibits the sodium ion fluxes necessary for impulse initiation and conduction to produce a local anaesthetic effect.

Also, see individual agents.

Onset:

• Within 20 to 30 minutes

Duration:

• Cream: 11 hours

Absorption:

• Determined by the duration of application and area where applied

Distribution:

• Lidocaine can cross the blood-brain barrier V : Lidocaine: Neonates: 2.75 L/kg; Adults: 1.1 L/kg

Protein binding:

• Lidocaine: 70%

Metabolism:

• Lidocaine: Undergoes hepatic metabolism by cytochrome P450 CYP1A2 and partially by CYP3A4 to inactive and active metabolites monoethylglycinexylidide (MEGX) and glycinexylidide (GX)
• Tetracaine: Plasma esterases cause hydrolysis to primary metabolites para-aminobenzoic acid and diethylaminoethanol

Half-life elimination:

• Lidocaine: Adults: 1.8 hours

Excretion:

• Lidocaine: Undergoes urine excretion as metabolites and parent drug

International Brand Names of Lidocaine and tetracaine:

• Pliaglis
• Synera
• Anestic Cream
• Pliaglis
• Pliapel
• Ralydan
• Rapydan
• Rapyden
• Telica

Lidocaine and Tetracaine Brand Names in Pakistan:

Numcaine