Comparative Pharmacology
Head-to-head clinical analysis: EMLA versus MARCAINE HYDROCHLORIDE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EMLA versus MARCAINE HYDROCHLORIDE.
EMLA vs MARCAINE HYDROCHLORIDE
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.
Bupivacaine is an amide-type local anesthetic that blocks voltage-gated sodium channels in nerve cell membranes, reversibly inhibiting nerve impulse propagation, particularly in sensory fibers.
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.
Adults: 0.5% solution infiltrated up to 175 mg (35 mL) for minor procedures; for major procedures, up to 225 mg (45 mL) with epinephrine. Repeat doses at 3-hour intervals. Maximum dose 400 mg with epinephrine.
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 2.5 to 3.5 hours in adults; may be prolonged in neonates (8-12 hours) or patients with hepatic impairment.
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.
Primarily hepatic metabolism; less than 5% excreted unchanged in urine. Metabolites are excreted renally, with a small amount in feces via biliary elimination.
Category C
Category C
Local Anesthetic
Local Anesthetic