The combination of tramadol HCI/acetaminophen provides a more rapid onset of action compared to tramadol HCI alone and a longer duration of action than acetaminophen alone. Therefore, the combination of tramadol and acetaminophen may be effective for the treatment of cancer pain as well as to allow lower cumulative daily dosages of each medication to be used.This is an open-label study. Patients will receive one-dose treatment of 37.5mg Tramadol/325mg Acetaminophen tablets.This study has been designed to investigate the following hypothesis:Tramadol hydrochloride/acetaminophen is effective in the treatment of breakthrough pain in cancer patients.The patients will complete basic questions on side effect at visits on entry, 10, 30 mins, and 1h.~The patients will receive only one dose treatment of Tramadol hydrochloride/Acetaminophen oral tablets throughout the study. The number of oral tablets be given will be depend on the total daily dose of around-clock medications. If around-clock medication is Tramadol <=400mg or codeine <=300mg or morphine <60mg, the breakthrough pain medication will be 1 tablet. If around-clock medication is morphine 60-120mg or Fentanyl >=25 ug/hr, the breakthrough pain medication will be 2 tablets.
The purpose of this study is to evaluate the analgesic effectiveness and safety of 37.5mg Tramadol hydrochloride/325mg Acetaminophen in the treatment of breakthrough pain in cancer patients.