What are the advantages of liposomal bupivacaine over regular bupivacaine?
The duration of action of bupivacaine is approximately 4 to 6 hours. Pain from surgery lasts well beyond the duration of bupivacaine, making it ineffective for most postoperative pain patients. The solution for this deficiency is to provide continuous infusion via a catheter; however, peripheral catheters are difficult to place, require high nursing maintenance, and the patients often cannot go home with them in place. Formulating bupivacaine so that it has an extended duration without increasing peak plasma levels is an attractive option over continuous infusions in selected patients. The liposomal delivery of bupivacaine extends the local residence time at the effector site, resulting in a 7-fold increase in T max and a 10-fold extension of the terminal half-life without increasing peak plasma concentrations. Clinical studies comparing liposomal-bupivacaine with standard bupivacaine has had mixed results, likely due to underpowering.