What is the normal amount of topical lidocaine (lidocaine) available and what are the common tube sizes in grams?

Topical Lidocaine: Available Formulations and Tube Sizes

Topical lidocaine is commonly available in 4% concentration in various tube sizes, with typical over-the-counter preparations ranging from 30g to 77g tubes. 1

Available Formulations

• Topical lidocaine is available in multiple formulations including:
  • 4% lidocaine cream (commonly available over-the-counter) 1
  • 5% lidocaine gel (prescription strength) 2
  • 4% lidocaine with 1% menthol combinations 1
  • EMLA cream (2.5% lidocaine/2.5% prilocaine) 3
  • Specialized compounded preparations (BLT: 20% benzocaine, 6% lidocaine, 4% tetracaine; LET: 4% lidocaine, 1:2000 epinephrine, 0.5% tetracaine) 3

Common Tube Sizes

• Over-the-counter preparations:
  • 30g tubes (common for facial applications) 4
  • 77g tubes (2.7 oz) for larger area applications 1
  • 5g single-use packets (for procedures like IUD insertion) 5

Safety Considerations

• Maximum safe dose for topical lidocaine should not exceed 9 mg/kg lean body weight 5
• Application with occlusive dressings can triple serum lidocaine levels compared to non-occlusive application 4
• Significant interindividual variability exists in absorption and metabolism of topical lidocaine 3
• Plasma concentrations typically remain below 0.6 μg/mL with standard applications, which is below toxic levels 4, 2

Application Guidelines

• For facial application:

  • 2.5g to 5g of 4% lidocaine is typically sufficient 4
  • Optimal anesthetic effect occurs between 35-40 minutes after application 6
  • Significant anesthesia begins at approximately 25-30 minutes 6

• For procedural use:

  • 4-5g of EMLA cream can be applied to the cervix for procedures like IUD insertion 5
  • For burn treatment, application at 1 mg/cm² concentration has shown efficacy 7

Cautions

• Avoid concurrent use with other local anesthetics to prevent toxicity 8, 9
• Monitor for signs of local anesthetic systemic toxicity, including circumoral numbness, facial tingling, slurred speech, and metallic taste 8
• Higher concentrations of lidocaine may be associated with more rapid onset but carry increased risk of systemic absorption 5
• OTC preparations should ideally be used under healthcare professional supervision due to unpredictable absorption in some individuals 3