Comparative Pharmacology
Head-to-head clinical analysis: LIDOCAINE HYDROCHLORIDE AND EPINEPHRINE versus XYLOCAINE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LIDOCAINE HYDROCHLORIDE AND EPINEPHRINE versus XYLOCAINE.
LIDOCAINE HYDROCHLORIDE AND EPINEPHRINE vs XYLOCAINE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Lidocaine is a sodium channel blocker that stabilizes neuronal membranes and inhibits action potentials, providing local anesthesia. Epinephrine is an alpha- and beta-adrenergic agonist that causes vasoconstriction, prolonging lidocaine's effect and reducing systemic absorption.
Lidocaine binds to and inhibits voltage-gated sodium channels in the neuronal membrane, stabilizing the membrane and preventing the initiation and conduction of nerve impulses, thereby producing local anesthesia.
Local anesthesia: 1% or 2% solution with epinephrine 1:100,000 or 1:200,000; maximum dose 7 mg/kg lidocaine (500 mg) in adults; administer by infiltration or nerve block, not to exceed 1 hour between doses.
1-5 mg/kg (max 300 mg) local infiltration; epidural: 1-2% solution, 5-20 mL.
None Documented
None Documented
Lidocaine: terminal elimination half-life is approximately 1.5–2.0 hours. With continuous infusion or hepatic impairment, half-life may be prolonged (up to 4–6 hours). Epinephrine: plasma half-life is about 2–3 minutes due to rapid uptake and metabolism.
Terminal elimination half-life is approximately 1.5 to 2 hours in adults, prolonged to 2-3 hours in patients with hepatic impairment, and may exceed 5 hours in neonates or patients with heart failure.
Lidocaine is primarily metabolized in the liver; approximately 90% of a dose is excreted in the urine as metabolites (including monoethylglycinexylidide and glycinexylidide), with less than 10% excreted unchanged. Epinephrine is metabolized by catechol-O-methyltransferase and monoamine oxidase, with metabolites excreted in urine.
Hepatic metabolism (primarily by CYP1A2 and CYP3A4) to metabolites, mainly monoethylglycinexylidide (MEGX) and glycinexylidide (GX); less than 10% excreted unchanged in urine. Renal excretion of metabolites: MEGX (70-80%) and GX (10-20%). Biliary/fecal elimination is minimal.
Category A/B
Category C
Local Anesthetic / Antiarrhythmic (Class Ib)
Local Anesthetic