Analgesia 1. Title: Sex Specific, Estrogen-dependent Modulation of Spinal Nociception via Selective Activation of Kappa-opioid Receptors in the Rat

Methods: Pregabalin utilization and its impact on concomitant medication use were assessed via a retrospective evaluation of 387 patients treated at Lahey Clinic Interventional Pain Management Center. Using an e-prescribing database, records were reviewed to assess utilization of pregabalin and concomitant medications for 3 months prior to and after the initiation of therapy. We assumed patients were adherent to all medications. For medications that were prescribed as needed (PRN), we assumed patients took medications at the maximum prescribed quantity and frequency. Daily narcotic utilization was standardized to morphine equivalent units. The use of other concomitant medications was counted as a dichotomous variable, based on the presence of a prescription. Results: The starting daily dose of pregabalin was 150 mg in a majority of patients (63.5%). This was also the last recorded dose for 50% of patients. We observed a significant decline in narcotic use, from 28.7% to 22.0% (p=0.031), and a significant increase in the use of topical lidocaine, from 3.4% to 6.7% (p=0.032). The use of antidepressants, other anticonvulsants, NSAIDs, muscle relaxants, and anxiolytics did not change significantly after the initiation of pregabalin. Of the 111 patients receiving narcotic analgesics prior to initiation of pregabalin, 61.3% experienced a reduction in narcotic use, 23.4% experienced no change and 15.3% experienced an increase in narcotic use. 47 of the 111 patients (42.3%) utilizing narcotics prior to the initiation of pregabalin discontinued use completely after the initiation of pregabalin. 22 of the 276 patients (8%) who were not utilizing narcotics in the 3-month period prior to pregabalin initiation had narcotics added to therapy after or at the same time pregabalin was initiated. Conclusions: Based on the results of this uncontrolled observational analysis, further investigation of concomitant medication use in pregabalin users in a randomized controlled trial is warranted. Disclosure: This study was supported by Pfizer, Inc. 4. Title: Treatment of post-bunionectomy acute pain with HC/APAP CR Presenter: Michael H. Golf, DPM, PA Biography: Dr. Golf is a podiatrist in private practice in Austin, Texas, with research facilities in conjunction with Scirex for bunionectomy studies in Austin and Houston. Co-presenters: Mark McDonnell, DPM, FACFAS, podiatrist at Hill Country Sports Medicine of Podiatric Surgery and at Texas State University, San Marcos; Stanton M. Smith, DPM, private-practice podiatrist in Murray, UT, SCIREX, Foot and Ankle Institute/Arlington Park Surgery Center in Salt Lake City; James W. Thomas, MS, Manager of Statistics at Abbott; Earle Lockhart, MD, Senior Medical Director of Pain Care at Abbott; Andrea Erickson Best, DO, MPH, Global Project Head of Pain Research and Development at Abbott; Rita I. Jain, MD, Divisional Vice President of Pain, Respiratory, and Metabolic Development at Abbott