Oxymorphone Extended Release (ER) in Opioid-Naive Patients With Chronic Pain

Inclusion Criteria: * Currently receive a stable non-opioid analgesic regimen * Have an initial pain intensity score of greater than or equal to 40 mm on a 100-mm Visual Analogue Scale (VAS) and a categorical pain rating of moderate or severe on a categorical scale of none, mild, moderate, or severe * If female, must be practicing abstinence or using a medically acceptable form of contraception * Understand written and spoken English * Have been informed of the nature of the study and provided written informed consent. Exclusion Criteria: * Positive pregnancy test (females only) * History of or active asthma or emphysema * Clinically significant hepatic impairment * Received any of the following medications within 48 hours prior to dosing: * Dextromethorphan-containing medications (over-the-counter \[OTC\] cough and cold preparations, such as Vicks Formula 44) * St. John's Wort \>1000 mg/day * Received monoamine oxidase inhibitor (MAOI) drugs within 2 weeks prior to dosing * Are not stabilized on the following medications for at least 4 weeks prior to dosing: * Tricyclic antidepressant drugs * Serotonin reuptake inhibitors * Amphetamines used for attention-deficit/hyperactivity disorder (ADHD) * History of alcohol or substance abuse within the last 3 years * History of opioid abuse within 6 months prior to study entry * Have a known oxymorphone sensitivity or allergy * Have scheduled an elective surgery or procedure during the study that would not permit continuation of study medication, and/ or require another analgesic not currently taken by the patient * Have received an investigational drug or product or participated in an investigational drug study within a period of 30 days prior to receiving study medication * Have a known allergy or significant reaction to opioids * Have been a participant in a previous oxymorphone clinical trial * Have a history of seizure (Patients with a history of juvenile febrile seizures may be included if there has been no seizure history within the past 10 years).