lidocaine/prilocaine topical (EMLA)

Introduction

lidocaine 2.5% & prilocaine 2.5%

Indications

• topical anesthetic for use on intact skin for use with IV cannulation or venipuncture
• topical anesthetic for painful procedures such as lumbar puncture & skin graft harvesting

Contraindications

• NOT for ophthalmic use

Caution:

• severe hepatic disease
• G6PD deficiency
• concurrent use of drugs associated with methemoglobinemia

pregnancy-category ?

safety in lactation ?

Dosage

(topical anesthesia)

• apply cream to region at least 1 hour prior to procedure
• apply 2.5 g/site
• for painful procedure apply 2 g/10 cm2 & leave on for 2 hours prior to procedure
• maximum area of application for infants & children
  • < 10 kg, < 100 cm2
  • 10-20 kg, < 600 cm2
  • > 20 kg, < 2000 cm2

Cream: 1:1 eutectic mixture containing lidocaine 2.5% & prilocaine 2.5% (5 g, 30 g)

Pharmacokinetics

• onset of action: 1 hour for sufficient dermal analgesia
• peak effect: 2-3 hours
• duration of action: 1-2 hours after removal of cream
• absorption is related to duration of applicaton & area applied
  • 3 hour application:
    • 3.6% of lidocaine & 6.1% of prilocaine absorbed
  • 24 hour application:
    • 16% of lidocaine & 34% of prilocaine absorbed
• both agents cross blood brain barrier
• 1/2life
  • lidocaine: 65-150 minutes, prolonged with hepatic or cardiac dysfunction
  • prilocaine: 10-150 minutes, prolonged with hepatic or renal dysfunction

Adverse effects

• not common (1-10%)
  • contact dermatitis, burning, stinging, angioedema
• uncommon (< 1%)
  • methemoglobinemia in infants, tenderness, urticaria, edema, urethritis

More general terms

• lidocaine/prilocaine
• topical anesthetic

More specific terms

• topical agent ELA Max

Components

• Lidocaine Topical
• lidocaine (Xylocaine)
• prilocaine; o-Methyl-2-propylaminopropionanilide (Propitocaine, Citanest)