Comparative Pharmacology
Head-to-head clinical analysis: EMLA versus LIDOCAINE HYDROCHLORIDE 5 AND DEXTROSE 7 5.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EMLA versus LIDOCAINE HYDROCHLORIDE 5 AND DEXTROSE 7 5.
EMLA vs LIDOCAINE HYDROCHLORIDE 5% AND DEXTROSE 7.5%
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
EMLA is a eutectic mixture of lidocaine 2.5% and prilocaine 2.5%. Lidocaine and prilocaine are amide-type local anesthetics that block sodium ion channels in neuronal membranes, inhibiting the initiation and conduction of nerve impulses, thereby producing local analgesia.
Lidocaine stabilizes the neuronal membrane by inhibiting sodium ion influx, thereby blocking the initiation and conduction of nerve impulses. Dextrose provides caloric support.
Apply a thick layer of cream (approximately 2.5 g per 20 cm²) to intact skin under an occlusive dressing for at least 1 hour for minor procedures; for dermal procedures on larger areas, apply up to 60 minutes before procedure, maximum single application area of 600 cm² in adults.
For IV administration, typical adult dose is 5-7 mg/kg intravenously as a single bolus, followed by 0.5-1 mg/kg every 5-10 minutes as needed, up to a maximum total dose of 200-300 mg. For epidural or caudal anesthesia, 15-20 mL of the 5% solution provides adequate block. For peripheral nerve block, 10-30 mL. Do not exceed 5 mg/kg per dose intravenously or 300 mg per dose by infiltration.
None Documented
None Documented
After topical application, the terminal elimination half-life of lidocaine is approximately 1.5-2 hours; prilocaine half-life is approximately 1.5 hours. In neonates, half-life may be prolonged due to immature hepatic function. Clinical context: Steady state is achieved within 12-24 hours with repeated application.
Terminal elimination half-life is approximately 1.5 to 2 hours in healthy adults after intravenous administration. In patients with heart failure or hepatic impairment, half-life may be prolonged to 4-6 hours or more. After epidural administration, half-life may be slightly longer due to ongoing absorption.
Lidocaine and prilocaine are metabolized in the liver; lidocaine metabolites (primarily 4-hydroxyxylidine) and prilocaine metabolites (primarily o-toluidine) are excreted renally. Less than 5% of unchanged lidocaine and prilocaine are excreted unchanged in urine. Fecal excretion is negligible.
Renal excretion of unchanged lidocaine and metabolites; less than 10% excreted unchanged in urine. Hepatic metabolism produces active metabolites (MEGX, GX) which are renally excreted. Biliary/fecal excretion negligible.
Category C
Category A/B
Local Anesthetic
Local Anesthetic / Antiarrhythmic (Class Ib)