An Efficacy and Safety Study of Transdermal Therapeutic System (TTS)-Fentanyl in Severe Chronic Low Back Pain

Inclusion Criteria: -Chronic low back pain with moderate to severe pain at least 3 months -Participants needed to be treated with strong opioid and haven't been treated with strong opioid in the past -Participants who still had moderate to severe pain (Visual Analog Scale \[VAS\] \>= 4), which was not adequately controlled by weak opioids such as tramadol or codeine at optimal doses (at least 120 milligram \[mg\] per day for tramadol or 200 mg per day for codeine) for at least 7 consecutive days -Participants who failed from other treatments such as operation or lack of efficacy of current treatment -Participant who has signed the informed consent form Exclusion Criteria: -Skin disease that prevent the use of the transdermal system or which could affect the absorption of fentanyl or local tolerability -History or suspicion of alcohol or drug abuse within the past 5 years -History of cardiac, nervous system or respiratory disease which in the investigator's judgment precludes participation in the study because of the potential for respiratory depression -Concomitant use of Non Steroidal Anti-Inflammatory Drugs (NSAIDs), Cyclooxygenase - 2 (COX-2), muscle relaxant, topical analgesic during the previous week (unless on stable drug dose for at least 1 month before study entry) -Pregnancy or breast-feeding female; female participants of childbearing potential without adequate contraception