Comparative Pharmacology
Head-to-head clinical analysis: EMLA versus XYLOCAINE DENTAL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EMLA versus XYLOCAINE DENTAL.
EMLA vs XYLOCAINE DENTAL
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 stabilizes the neuronal membrane by inhibiting sodium ion influx, thereby blocking the initiation and conduction of nerve impulses.
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.
Xylocaine Dental (lidocaine HCl 2% with epinephrine 1:100,000 or 1:50,000): For infiltration/inferior alveolar nerve block, maximum dose 3.4 mg/kg (4.5 mg/kg with epinephrine 1:100,000) not to exceed 300 mg; usual adult dose: 1–5 mL (20–100 mg) administered via oral submucosal injection.
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.
1.5–2 hours in adults with normal hepatic function. Prolonged to 2–3 hours in patients with hepatic impairment or congestive heart failure; may exceed 5 hours in severe hepatic disease.
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 drug and metabolites accounts for >95% of the dose. Approximately 70% is excreted as the metabolite 4-hydroxy-2,6-xylidine; less than 10% is unchanged lidocaine. Biliary/fecal excretion is minimal (<5%).
Category C
Category C
Local Anesthetic
Local Anesthetic