Comparative Pharmacology
Head-to-head clinical analysis: EMLA versus LIDOCAINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EMLA versus LIDOCAINE.
EMLA vs LIDOCAINE
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 sodium channel blocker that inhibits the influx of sodium ions into cardiac Purkinje fibers and myocytes, thereby stabilizing the neuronal membrane and decreasing automaticity. It also exhibits local anesthetic effects by reversibly binding to voltage-gated sodium channels in nerve cell membranes, blocking impulse conduction.
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 ventricular arrhythmias: IV bolus 1-1.5 mg/kg, then continuous infusion 1-4 mg/min. For local anesthesia: 0.5-2% solution, max 4.5 mg/kg (300 mg) without epinephrine, 7 mg/kg (500 mg) with epinephrine.
None Documented
Clinical Note
moderateLidocaine + Fluticasone propionate
"The risk or severity of adverse effects can be increased when Lidocaine is combined with Fluticasone propionate."
Clinical Note
moderateLidocaine + Tenofovir disoproxil
"The metabolism of Tenofovir disoproxil can be decreased when combined with Lidocaine."
Clinical Note
moderateLidocaine + Sulfisoxazole
"The metabolism of Sulfisoxazole can be decreased when combined with Lidocaine."
Clinical Note
moderateLidocaine + Erythromycin
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 (normal hepatic function). In CHF or hepatic impairment, prolonged to 6-8 hours; in neonates, 3-6 hours. Context: rapid redistribution after IV bolus (alpha half-life ~8 min) accounts for brief clinical effect, while terminal half-life determines accumulation with infusion.
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: 4-hydroxyxylidine (70-80% renal, 10-20% biliary/fecal), unchanged lidocaine <10% renal. Total renal elimination ~90% (as metabolites), biliary/fecal ~10%.
Category C
Category A/B
Local Anesthetic
Local Anesthetic / Antiarrhythmic (Class Ib)
"The metabolism of Erythromycin can be decreased when combined with Lidocaine."