A Long-term Efficacy and Safety Study of Tramadol Hydrochloride Plus Acetaminophen (JNS013) in Japanese Participants With Chronic Pain

The purpose of this study is to evaluate the efficacy and safety of tramadol hydrochloride plus acetaminophen (JNS013) with long term administration in participants with chronic pain.

This is an open-label (both physician and participant know the name of the study drug), non-randomized, multicenter (when more than one hospital or medical school team work on a medical research study) and long-term efficacy and safety study of JNS013 (combination of tramadol hydrochloride (TRAM) with acetaminophen \[APAP\]) in participants with chronic pain (aching sensation that persists for more than a few months. It may or may not be associated with trauma or disease, and may persist after the initial injury has healed. Its localization, character, and timing are more vague than with acute pain). This study consists of 4 periods; screening period: 1 week, treatment period I: 4 weeks, treatment period II: 48 weeks and follow-up period: 1 week. During Treatment Period I, restrictions on concomitant treatments will be established and the participants will be treated with one or two tablets of JNS013, four times daily for four weeks. During Treatment Period II, the participants will be treated for 48 weeks using the same dosing method and dose level for JNS013 as was used during Treatment Period I, permitting modifications to the concomitant drugs/therapies as during normal medical care. Throughout both Treatment Period I and Treatment Period II, the decision will be made to permit the participants to select to use either one or two tablets of JNS013 per dose according to the extent of the participant's pain and tolerability. The total duration of treatment period will be of 52 weeks. Efficacy will be assessed using change from baseline in Visual Analogue Scale for pain (VAS24) score at the pre-defined time point until Week 52. Participants safety will be monitored throughout the study.

Eligibility Criteria:
Inclusion Criteria:

* Participants whose pain cannot be controlled sufficiently with at least 14-day continuous treatment with identical oral non steroid anti inflammatory drugs (NSAIDs) at a usual maximum dose during 3 months prior to this study
* Ambulatory participants without need for any supportive device or assistance during daily life
* Outpatients
* Participants who do not plan to change the therapeutic policy and content of the medications for underlying disease during screening period to the end of Treatment Period I
* Sustention of chronic pain due to Osteo Arthritis (OA), Low Back Pain (LBP), Rheumatoid Arthritis (RA), Neck Shoulder Arm Syndrome (NSAS), Diabetic Neuropathy (DN), Post herpetic Neuralgia (PHN) or other for at least 3 months

Exclusion Criteria:

* Participants with conditions for which opioids are contraindicated
* Participants with conditions for which APAP are contraindicated
* Participants with history of convulsion or the possibility of convulsive seizure
* Participants with concurrent, previous, or possible alcohol dependence, drug dependence, or narcotic addiction
* Pregnant Participants or those who may be pregnant, lactating mothers, and Participants who wish pregnancy during the study period.