James L Rothschiller MD PA

Pediatric Anesthesiologist

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Local Anesthetic (LA) Admixtures

Revised 20201111 – Rothschiller, MD

Drug Dilutions for Local Anesthetic Injection

To make 40 mL of Lidocaine 0.25% with 5 mcg/mL of epinephrine:

  • Add 10 mL of Lidocaine HCl 1%, Preservative Free, 10 mg/mL
  • Add 30 mL of Sterile Sodium Chloride 0.9%, Preservative Free
  • Add 0.2 mL of Epinephrine 1mg/mL (1:1000) Solution

Maximum lidocaine single dose with epinephrine vasoconstrictor is 6-7 mg/kg (infiltration) – not to exceed a 500 mg total dose.

  • For example, Lidocaine 0.25% contains 2.5 mg of lidocaine per 1 mL. Therefore the maximum volume of 0.25% lidocaine with epinephrine that can be administered to a 10 kg patient  = 70 mg / 2.5 mg/mL = 28 mL

To convert 1:200,000 to mcg/mL: Divide 1,000,000 by the second number = 1,000,000/200,000 = 5 mcg/mL

10 mL Vial Local Anesthetic 

  • 1:50,000 Epinephrine Admixture: Add 0.2 mL epinephrine (1:1,000) to 10 mL of LA
  • 1:100,000 Epinephrine Admixture: Add 0.1 mL epinephrine (1:1,000) to 10 mL of LA
  • 1:200,000 Epinephrine Admixture: Add 0.05 mL epinephrine (1:1,000) to 10 mL of LA

20 mL Vial Local Anesthetic

  • 1:50,000 Epinephrine Admixture: Add 0.4 mL epinephrine (1:1,000) to 20 mL of LA
  • 1:100,000 Epinephrine Admixture: Add 0.2 mL epinephrine (1:1,000) to 20 mL of LA
  • 1:200,000 Epinephrine Admixture: Add 0.1 mL epinephrine (1:1,000) to 20 mL of LA

Local Anesthetic Drug Nomenclature:

  • Lidocaine Hydrochloride Injection (Xylocaine®, lignocaine) 
  • Ropivacaine Hydrochloride Injection (Naropin®)
  • Bupivacaine Hydrochloride Injection (Marcaine®, Sensorcaine®)

Epinephrine is the generic name (recommended international non-proprietary name) which is the same as adrenaline (British approved name). The proprietary (brand or trade) name is the name given by a pharmaceutical manufacturer. It is capitalized and the ® is added.

Concentration of Diluted Drugs

  • 1:100 is the same as 1% Solution or a 10 mg/mL or 10,000 mcg/mL
  • 1:1,000 is the same as 0.1% Solution or 1 mg/mL or 1,000 mcg/mL
  • 1:10,000 is the same a 0.01% Solution = 0.1 mg/mL or 100mcg/mL
  • 1:100,000 is the same as 0.001 % solution = 0.01 mg/mL or 10 mcg/mL
  • 1:200,000 is the same as  0.0005% solution = 0.005 mg/mL or 5 mcg/mL

Convert 1:200,000 to mcg/mL: Divide 1,000,000 by the second number = 1,000,000/200,000 = 5 mcg/mL

Regular normal saline NS (0.9 % sodium chloride) and bNS [0.9 % sodium chloride with benzyl alcohol, United States Pharmacopeia (USP)]. Bacteriostatic Sodium Chloride Injection, USP is a sterile, non-pyrogenic, isotonic solution of sodium chloride (0.9 %) in water for injection.