A Repeated Dose Study of the Metabolism and Action Evaluation of OROS Hydromorphone HCI (Slow Release) Tablets in Patients With Chronic Pain

Inclusion Criteria: * Patients who had chronic nonmalignant or chronic cancer pain and were currently receiving strong oral or transdermal opioid analgesics (drug that relieves pain) on a daily basis or patients suitable for advancement of therapy to step 3 on the WHO (World Health Organization) analgesic (drug that relieves pain) ladder * Patients who required the opioid equivalent of at least 32 mg but no more than 300 mg of oral morphine sulfate or opioid equivalent (exclusive of breakthrough pain medication) every 24 hours for the management of chronic nonmalignant or cancer pain * Patients who were expected to have reasonably stable opioid requirements for the duration of the study Exclusion Criteria: * Patients intolerant of or hypersensitive to hydromorphone (or other opioid drugs) * Patients who were pregnant or breast-feeding.Patients with any dysphagia or unable to swallow tablets, acute abdominal conditions that may be obscured by opioids or gastrointestinal disorders, including pre-existing severe GI narrowing, that may affect the absorption or transit of orally administered drugs * Patients with any significant CNS disorder, including but not limited to head injury, intracranial lesion, increased intracranial pressure, seizure disorder, stroke within the past 6 months, and disorders of cognition, and clinically significant impaired hematological function * Patients that may be at risk for serious decreases in blood pressure following administration of an opioid analgesic (pain relief)