Comparative Pharmacology
Head-to-head clinical analysis: ALPHACAINE versus POSIMIR.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ALPHACAINE versus POSIMIR.
ALPHACAINE vs POSIMIR
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
ALPHACAINE is a local anesthetic that binds to the intracellular portion of voltage-gated sodium channels, blocking sodium influx and preventing depolarization and conduction of nerve impulses.
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.
10-20 mg IM or IV every 4-6 hours as needed; maximum 80 mg/day.
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: 3.5-5.0 hours (prolonged in hepatic impairment; requires dose adjustment in Child-Pugh B or C).
Terminal elimination half-life is approximately 27 hours (range 16-38 hours), supporting once-daily dosing in clinical use.
Renal: ~60-70% unchanged; Hepatic metabolism: ~20-30% via CYP3A4 and CYP2C9; Fecal: <10%.
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