Comparative Pharmacology
Head-to-head clinical analysis: EMLA versus LIDOCAINE HYDROCHLORIDE VISCOUS.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EMLA versus LIDOCAINE HYDROCHLORIDE VISCOUS.
EMLA vs LIDOCAINE HYDROCHLORIDE 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 a local anesthetic that stabilizes neuronal membranes by blocking voltage-gated sodium channels, thereby inhibiting the initiation and propagation of action potentials. It also has antiarrhythmic properties (Class Ib) by accelerating repolarization and reducing automaticity in cardiac tissues.
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.
Adult: 15 mL (300 mg) orally every 3 hours, not to exceed 8 doses in 24 hours. Viscous formulation swished and swallowed.
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 (adults); prolonged in heart failure (2.5–4 hours) or hepatic disease (up to 5–7 hours). Context: short t1/2 limits toxic accumulation with topical use.
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: ~90% as metabolites (mainly 4-hydroxy-2,6-xylidine and glucuronides), <10% unchanged. Biliary/fecal: minor (<5%).
Category C
Category A/B
Local Anesthetic
Local Anesthetic / Antiarrhythmic (Class Ib)