A single injection of bupivacaine – currently the longest-duration local anesthetic approved for clinical use in peripheral nerve blocks (bupivacaine or levobupivacaine) – rarely lasts as long as postoperative pain. Therefore, patients often must endure multiple days with insufficient analgesia. Multiple adjuvants may be used to prolong the local anesthetic effects, such as clonidine or epinephrine. However, there is currently no U.S. Food and Drug Administration (FDA)-approved medication that reliably extends the duration of single-injection epidural or peripheral nerve blocks for over 24 hours. And while continuous peripheral nerve blocks can provide analgesia for multiple days, this modality is frequently not provided by health care providers due to time, financial, hospital and practice structure limitations (e.g., lack of an available provider at night/weekends). A single-injection medication providing multiple days of postoperative analgesia would be a powerful tool for those involved with acute pain medicine.
Liposomes: First proposed as a medication...
