Study to Evaluate Analgesic Effect of IV Administration of Kappa Agonist CR845 For Hysterectomy Surgery

Inclusion Criteria: * Able to provide written informed consent prior to any study procedures; * Able to communicate clearly with the Investigator and staff; * Female between 21 and 65 years of age, inclusive; * Scheduled for elective laparoscopic hysterectomy under general anesthesia; * Negative result on serum pregnancy test at screening and negative urine pregnancy test at Baseline (for women of child-bearing potential only) and not currently breast feeding, or planning to do so within 30 days of dosing; * Negative urine drug screen for drugs of abuse at Screening and at Baseline; * American Society of Anesthesiologists (ASA) risk class of I to III; * Body mass index (BMI) between 17 and 40 inclusive. Exclusion Criteria: * Has known allergies to opioids, or hypersensitivity to other materials (such as infusion line) or medications to be used in the study; * Has a known or suspected history of Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV)-diagnosed alcohol, opiate or other drug abuse or dependence within 12 months prior to screening; * Is unable to refrain from alcohol consumption for a period beginning 24 hours prior to surgery through the end of the Treatment Period; * Is scheduled to undergo a hysterectomy that will utilize any type of robotic technology and/or a concomitant surgical procedure that would produce a significantly greater degree of surgical trauma than the laparoscopic hysterectomy or laparoscopic assisted vaginal hysterectomy alone; * Has taken non-opioid analgesics (including cyclooxygenase-2 \[COX-2\] inhibitors) or nonsteroidal anti-inflammatory drugs (NSAIDs) within 12 hours of the Baseline assessments; * Has taken any opioid analgesics or used systemic steroids within 4 days of surgery OR has previously used opiates chronically for a period of ≥3 months; * Has used antipsychotics, antiepileptics, sedatives, hypnotics, or antianxiety agents, selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants for \< 30 days prior to surgery or had a dose change within the previous 30 days; * Has taken any prescription or over-the-counter medication within 3 days prior to surgery that, in the opinion of the Investigator, is expected to confound the analgesic response; * Has taken herbal agents or nutraceuticals (i.e., chaparral, comfrey, germander, gin bu huan, kava, pennyroyal, skullcap, St. John's wort, or valerian) 7 days prior to surgery; * In the opinion of Investigator shows clinical signs of hypovolemia; * Has an oxygen saturation \< 92% on room air at Screening or prior to receiving the first infusion of study drug; * Has any history of clinically significant cardiovascular disease, * Has a clinically significant abnormal electrocardiogram (ECG) or a history of additional risk factors for torsades de pointes (e.g., heart failure, hypokalemia, family history of Long QT Syndrome); * Has a history of any serious medical conditions that in the opinion of the Investigator would preclude study participation; * Has serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase, or gamma glutamyl transferase (GGT) \>2.5 x the upper limit of normal (ULN) at screening; * Has bilirubin, blood urea nitrogen (BUN), or creatinine \>1.5 x the reference ULN at Screening; * Has abnormally low hemoglobin \< 10 mg/dl at Screening; * Has serum sodium levels \> 146 mmol/L at Screening; * Has impaired renal function (creatinine clearance \[CrCl\] \< 50 ml/min) at Screening; * Has a positive test for human immunodeficiency virus (HIV) or known history of HIV infection; * Has received another investigational drug within 30 days of scheduled surgery; * Has a significant chronic pain condition in areas unrelated to the operative site at the time of Screening that in the Investigator's opinion could confound the interpretation of study results