Comparative Pharmacology
Head-to-head clinical analysis: LIDOCAINE HYDROCHLORIDE W EPINEPHRINE versus POSIMIR.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LIDOCAINE HYDROCHLORIDE W EPINEPHRINE versus POSIMIR.
LIDOCAINE HYDROCHLORIDE W/ EPINEPHRINE vs POSIMIR
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Lidocaine is a sodium channel blocker that inhibits voltage-gated sodium channels, preventing depolarization and conduction of nerve impulses. Epinephrine is an alpha- and beta-adrenergic agonist that causes vasoconstriction, reducing systemic absorption of lidocaine and prolonging local anesthetic effect.
Bupivacaine, the active ingredient in POSIMIR, is an amide-type local anesthetic that blocks voltage-gated sodium channels in nerve cell membranes, inhibiting the generation and conduction of nerve impulses. POSIMIR is a bupivacaine extended-release liposomal formulation designed for sustained release at the surgical site.
Local anesthesia: 1-5 mL of 1% or 2% solution with epinephrine 1:100,000 or 1:200,000; maximum dose 7 mg/kg lidocaine (500 mg without epinephrine, 7 mg/kg with epinephrine) per procedure. Intravenous: 1-1.5 mg/kg bolus for ventricular arrhythmias, followed by continuous infusion 1-4 mg/min.
Posimir (bupivacaine) is administered as a single intra-articular injection into the subacromial space following arthroscopic shoulder surgery. The recommended adult dose is 5 mL (66 mg) of the 1.32% solution.
None Documented
None Documented
Terminal half-life 1.5-2 hours (single dose), prolonged to 2-3 hours with continuous infusion; in heart failure or hepatic cirrhosis, half-life may exceed 5 hours.
Terminal elimination half-life is approximately 27 hours (range 16-38 hours), supporting once-daily dosing in clinical use.
Renal: unchanged drug <10%, major metabolites (MEGX and GX) ~70% renal; biliary: <10% fecal; total clearance ~10-20 mL/min/kg. Renal impairment prolongs elimination of metabolites.
Primarily hepatic metabolism via CYP3A4 and CYP1A2 to inactive metabolites; <5% excreted unchanged in urine. Biliary/fecal excretion accounts for >90% of total clearance.
Category A/B
Category C
Local Anesthetic / Antiarrhythmic (Class Ib)
Local Anesthetic