 This prospective, randomized, controlled trial will investigate whether perioperative memantine has a postoperative analgesic effect following radical retropubic prostatectomy RRP. 100-110 patients scheduled to undergo RRP at Duke will be assessed preoperatively for allodynia using Von Frey filaments, then stratified into two groups based on the presence or absence of allodynia. Patients in each group will then be randomized to receive either memantine 20 mg or placebo 30-60 minutes preoperatively, followed on postoperative day 1 with either memantine 10 mg in the morning and 10 mg in the evening for memantine patients, or placebo at the same intervals for placebo patients. Data such as morphine consumption, patient satisfaction and pain scores, opioid-related side effects, and the area of hyperalgesia around the surgical incision will be recorded for the initial 48 hours postoperatively, and patient satisfaction with their postoperative analgesia will be assessed after 1 week. At 1, 3, and 6 months postoperatively, patients will be asked about the presence and intensity of any persistent pain related to surgery. 