Abstract
OVERVIEW OF LITERATURE: There are no established treatments for low back pain. Conventional treatments include physiotherapy and pharmacological treatments, such as non-steroidal anti-inflammatory drugs (NSAIDs). Recently, analgesics with mechanisms of action different from those of NSAIDs have emerged. Tramadol formulations have especially attracted attention for being effective among patients in whom NSAIDs are not entirely effective. However, they are associated with side effects that can disrupt treatment. Tramadol hydrochloride immediate-release and extended-release tablets have been recently launched. Herein, we report our experience with these formulations in chronic low back pain patients. PURPOSE: To investigate the incidence of side effects and the analgesic effect of tramadol hydrochloride immediate-release and extended-release tablets in patients with chronic low back pain. METHODS: This was a multicenter retrospective observational study. The study included patients prescribed tramadol hydrochloride immediate-release and extended-release tablets for chronic low back pain at 13 facilities in Japan between January 2021 and December 2023. The primary outcome was the incidence of side effects observed during the study period. The secondary outcomes were changes in the visual analog scale (VAS) score. RESULTS: The incidence of side effects was 37.7% (40/106 cases), which included constipation, nausea, drowsiness, and dizziness in 23 (21.7%), 13 (12.3%), 4 (3.8%), and 2 (1.9%) cases, respectively. The rate of treatment discontinuation owing to side effects was relatively low (16/106 cases, 15.1%). Furthermore, after four weeks of treatment, we found a significant reduction in the VAS scores for low back pain from baseline. CONCLUSION: This study shows the incidence of side effects following the administration of tramadol hydrochloride immediate-release and extended-release tablets. Regarding the breakdown of side effects, constipation, nausea, drowsiness, and dizziness were noted. Regarding pain evaluation, we found a significant reduction in the VAS scores for low back pain from baseline after four weeks of treatment, suggesting that tramadol hydrochloride immediate-release and extended-release tablets may provide excellent analgesic effects owing to their pharmacokinetic properties that ensure stable tramadol concentrations in the bloodstream.