Comparative Pharmacology
Head-to-head clinical analysis: EMLA versus POLOCAINE MPF.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EMLA versus POLOCAINE MPF.
EMLA vs POLOCAINE-MPF
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.
Polocaine-MPF (mepivacaine hydrochloride) is an amide-type local anesthetic that blocks sodium ion channels in nerve cell membranes, thereby preventing the initiation and propagation of nerve impulses. This results in reversible loss of sensation in the area of administration.
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: 1-2 cartridges (1.8 mL each) of 2% lidocaine with 1:100,000 epinephrine administered via local infiltration or nerve block, not to exceed 7 mg/kg (maximum 500 mg) for lidocaine.
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: 1.5-2.0 hours in adults; prolonged in hepatic impairment (up to 4-6 hours) and severe renal impairment. Clinical context: short half-life supports continuous infusion for sustained effect.
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, primarily 4-hydroxy-2',6'-dimethylacetanilide and pipecoloxylidide; unchanged drug <5%. Biliary/fecal: <5%.
Category C
Category C
Local Anesthetic
Local Anesthetic