Long-term Safety of Once-daily Hydrocodone Bitartrate (HYD) Tablets For Moderate to Severe Chronic Nonmalignant and Nonneuropathic Pain. Includes a 24-week Extension Period.

Inclusion Criteria include: * Male and female subjects ≥ 18 years of age with moderate to severe, chronic nonmalignant and nonneuropathic pain (lasting several hours daily) as their predominant pain condition for at least 3 months prior to the screening visit; * Subjects deemed by the investigator/medically qualified designee (must be MD or DO) to be appropriate candidates for the protocol specified, around the clock HYD therapeutic regimen; * Female subjects who are premenopausal or postmenopausal less than 1 year and who have not had surgical sterilization (ie, tubal ligation, partial or complete hysterectomy) must have a negative serum pregnancy test, be nonlactating, and willing to use adequate and reliable contraception throughout the study (eg, barrier with additional spermicidal foam or jelly, intra-uterine device, hormonal contraception); * Subjects who are willing and able to be compliant with the protocol, are capable of subjective evaluation (ie pain scores), are able to read and understand questionnaires, are willing and able to use an electronic diary, and are able to read, understand, and sign the written informed consent form in English. Exclusion Criteria include: * Subjects taking opioid analgesic(s) equivalent to \> 120 mg/day of oxycodone during the 14 days prior to the screening visit; * Subjects who previously participated in an investigational hydrocodone study within 90 days prior to the first dose of study medication ; * Subjects who have used any i…