Data on Phase III trials of Sustained Release Bupivacaine (Exparel) were presented at the American Society of Regional Anesthesia and Pain Medicine meeting in April. While not initially FDA approved for nerve blocks, this data suggests that it is quite effective in preventing pain after total knee replacement. Pain was reduced, more patients were pain-free, and more patients were "extremely satisfied" with their pain relief. Pacira pharmaceuticals, maker of Exparel, has said they intend to submit a supplemental New Drug Application to the FDA yet this year seeking approval for use of Exparel in nerve blocks. Sustained release (liposomal suspension) local anesthetics are of interest in preventing post-operative pain because a one time injection may significantly reduce pain for three days. Injecting another local anesthetic can result in the immediate release of a large dose of the liposomal encapsulated local anesthetic resulting in systemic toxicity and it remains to be seen whether or not this becomes a significant safety risk. Click here for more information.