In the present patient population, leg pain was reportedly much more serious than LBP (Fig. ​11). Tramadol/acetaminophen relieved leg pain within 7 days, while LBP was unchanged until many weeks later. In this study, radiculopathy could possibly be related to spinal lesions for instance a herniated disc. By contrast, nonspecific LBP is hard to diagnose and treat even using tramadol/acetaminophen. When tramadol/aceta-minophen was continually administered for one month, LBP was alleviated (Fig. ​11), indicating that LBP can be a more technical condition than radicular pain.

Tramadol is known as substantially excreted by the kidney, along with the chance of negative effects to this drug may be greater in patients with impaired renal function. Because elderly patients may have decreased renal function, care should be drawn in dose selection, also it may be beneficial to monitor renal function.