Comparative Pharmacology
Head-to-head clinical analysis: EXPAREL versus POSIMIR.
Peer-Reviewed Evidence
Head-to-head clinical analysis: EXPAREL versus POSIMIR.
EXPAREL vs POSIMIR
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Liposomal bupivacaine is a local anesthetic that blocks sodium channels in nerve cell membranes, inhibiting nerve impulse conduction and providing prolonged analgesia.
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 infiltration: up to 266 mg (20 mL) as a single dose; interscalene brachial plexus block: up to 133 mg (10 mL); femoral nerve block: up to 133 mg (10 mL). Maximum dose 266 mg. Administer via slow injection with frequent aspiration.
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 elimination half-life is 12-48 hours (mean ~24 hours), reflecting prolonged release from the multivesicular liposome depot.
Terminal elimination half-life is approximately 27 hours (range 16-38 hours), supporting once-daily dosing in clinical use.
Renal (approximately 96% as metabolites, <10% unchanged). Biliary/fecal excretion is negligible.
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 C
Category C
Local Anesthetic
Local Anesthetic