How to Prepare 1.5% Lidocaine Solution from 2% Solution
To prepare a 1.5% lidocaine solution from a 2% solution, mix 3 parts of 2% lidocaine with 1 part of sterile diluent (such as normal saline or sterile water). This dilution method follows standard pharmaceutical compounding principles for local anesthetics.
Detailed Preparation Method
Calculate the required volumes using the formula: C₁V₁ = C₂V₂, where C₁ is the initial concentration (2%), V₁ is the initial volume, C₂ is the target concentration (1.5%), and V₂ is the final volume 1
For a practical example, to prepare 10 ml of 1.5% lidocaine solution:
Ensure sterile technique is maintained throughout the preparation process to prevent contamination 1
Important Considerations
Use appropriate sterile syringes for measuring and mixing the solution 1
Prepare the solution immediately before use for optimal efficacy 1
Label the prepared solution clearly with:
- Medication name and concentration (1.5% lidocaine)
- Date and time of preparation
- Expiration time 1
Refrigerate the prepared solution if not used immediately and discard after 24 hours 1
Shake well before use to ensure proper mixing 1
Clinical Applications
The 1.5% concentration is commonly used for:
The diluted 1.5% solution may be preferred when a lower concentration is needed to reduce toxicity risk while maintaining adequate anesthetic effect 3, 4
Safety Precautions
Always verify calculations before preparing the solution to prevent medication errors 1
Remember that the maximum safe dose of lidocaine is 4.5 mg/kg without epinephrine and 7 mg/kg with epinephrine 1
Monitor for signs of lidocaine toxicity including perioral tingling, tinnitus, light-headedness, and restlessness 1
Have lipid emulsion 20% readily available in case of lidocaine toxicity 1