Tapentadol Prolonged Release (PR) Versus Oxycodone/Naloxone Prolonged Release in Severe Chronic Low Back Pain With a Neuropathic Component.

All participants started with 50 mg tapentadol hydrochloride prolonged release (twice daily). The dose of tapentadol hydrochloride prolonged release will be adjusted in increments of 50 mg to a level that provided adequate analgesia. Titration will be after a minimum of 3 days on a dose. Participants are permitted a maximum dose of 250 mg twice a day (500 mg total daily dose). After titration participants will remain on the stable dose for 9 weeks.

All participants start with 10 mg/5 mg oxycodone/naloxone (twice daily). The dose of oxycodone/naloxone may be adjusted in increments of 10mg/ 5 mg oxycodone/naloxone to a level that provide adequate analgesia. Titration will be after a minimum of 3 days on a dose. Participants will be permitted a maximum dose of 50 mg/ 20 mg oxycodone/naloxone twice daily a day (100 mg/40 mg total daily dose). After titration participants will remain on the stable dose for 9 weeks.