Comparative Pharmacology
Head-to-head clinical analysis: EMLA versus XYLOCAINE VISCOUS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EMLA versus XYLOCAINE VISCOUS.
EMLA vs XYLOCAINE VISCOUS
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 is an amide-type local anesthetic that blocks voltage-gated sodium channels, inhibiting nerve impulse propagation and reducing pain sensation.
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: 5-15 mL orally (or swish and spit) 4-6 times daily, not to exceed 4 doses in 12 hours or 30 mL in 12 hours.
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: 1.5-2 hours in adults; prolonged in hepatic impairment or heart failure (up to 6-8 hours). In neonates, half-life may be 3-6 hours due to immature metabolism.
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 metabolites: ~90%. Unchanged drug: <10%. Biliary/fecal: minor.
Category C
Category C
Local Anesthetic
Local Anesthetic