Evaluation of Effectiveness and Tolerability of Tapentadol Hydrochloride in Subjects With Severe Chronic Low Back Pain Taking Either WHO Step I or Step II Analgesics or no Regular Analgesics

Inclusion Criteria

• Participants must have signed an Informed Consent Form.
• Participants were men or non-pregnant, non-lactating women. Female participants must be postmenopausal, surgically sterile, or practicing an effective method of birth control. Women of childbearing potential must have a negative pregnancy test at screening.
• Participants must be appropriately communicative to verbalize and to differentiate with regard to location and intensity of the pain.
• Participants must be at least 18 years of age.
• Participants must have a diagnosis of chronic low back pain; chronic pain defined as pain lasting for at least 3 months.
• If the participant has radicular pain, this must have been present for at least 3 months and stable for the 4 weeks before enrollment.
• Participants's pain must require a strong analgesic (defined as WHO Step III) as judged by the Investigator.
• Participants must report a rate of satisfaction with their previous analgesic regimen not exceeding "fair" on a subject satisfaction with treatment scale (5-point VRS).
• If under regular, daily pretreatment:
• Participants must be taking a WHO Step I or Step II analgesic medication on a daily basis for at least 2 weeks prior to the Screening Visit.
• The Investigator considers dose increase of WHO Step I analgesics (as mono- or combination therapy) and/or continuation with or dose increase of WHO Step II analgesics inadequate for the individual participant, whatever applicable.
• Participants must have an average pain intensity score (NRS 3) greater than 5 points during the last 3 days prior to the Screening Visit. or
• If no regular analgesic pretreatment is reported:
• Participants must have an average pain intensity score (NRS-3) greater than 6 points in the last 3 days prior to the Screening Visit and related to low back pain.

Exclusion Criteria

• Presence of a clinically significant disease or laboratory findings that in the Investigator's opinion may affect efficacy or safety assessments.
• Presence of active systemic or local infection that may, in the opinion of the Investigator, affect the efficacy, quality of life/function or safety assessments.
• History of alcohol or drug abuse, or suspicion of in Investigator's judgement.
• Presence of concomitant autoimmune inflammatory conditions.
• Known history of or laboratory values reflecting severe renal impairment.
• Known history of moderately or severely impaired hepatic function.
• History of or active hepatitis B or C within the past 3 months or history of HIV infection
• History of seizure disorder or epilepsy.
• Any of the following within 1 year: mild/moderate traumatic brain injury, stroke, transient ischemic attack, or brain neoplasm. Severe traumatic brain injury within 15 years (consisting of 1 or more of the following: brain contusion, intracranial hematoma, either unconsciousness or post-traumatic amnesia lasting more than 24 h) or residual sequelae suggesting transient changes in consciousness.
• Pregnant or breast-feeding.
• History of allergy to, or hypersensitivity to tapentadol hydrochloride or its excipients, or contraindications related to tapentadol hydrochloride including:
• Participants with acute or severe bronchial asthma or hypercapnia.
• Participants who have or are suspected of having paralytic ileus.
• Employees of the Investigator or trial site, with direct involvement in this trial or other trials under the direction of the Investigator or trial site, as well as family members of employees of the Investigator.
• Participation in another trial concurrently or within 4 weeks prior to the Screening Visit.
• Known to or suspected of not being able to comply with the protocol and the use of the investigational medicinal product.
• Use of monoamine oxidase inhibitors within 14 days before the Screening Visit.
• Non-stable dosing of selective serotonin reuptake inhibitors within 30 days before the Screening Visit (the doses must remain stable during the trial).

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