Analgesic efficacy of tapentadol, alone or in combination, in patients with neuropathic pain (DN): experience in 80 cases

Abstract

Introduction: The objective of this work focuses on assessing the analgesic efficacy of tapentadol and its influence on quality of life in patients with neuropathic pain (NP), as well as elucidating whether there is analgesic synergism between tapentadol and pregabalin, gabapentin or duloxetine. In addition, an attempt was made to find a correlation between the DN4 and Pain Detect diagnostic tests. Material and methods: A prospective, randomized, placebo-controlled study was conducted in 80 patients with DN who were evaluated at a baseline visit. Subsequently, they were randomized into four groups: group 1: tapentadol + placebo; group 2: tapentadol + pregabalin; group 3: tapentadol + gabapentin; and group 4: tapentadol + duloxetine. At the 1.st and 3.rd month visits, VAS, DN4, Pain Detect, BPI, side effects and drug doses were evaluated and, at the 3.rd month visit, the patient's impression of global improvement was also evaluated with the PGI. -YO. Statistical analysis (per protocol) was performed using SPSS 14.0 for Windows. Tests were used such as the t-Student for the comparison of means, the Mann-Whitney for the statistical significance of the % improvement between groups, the non-parametric Wilcoxon signed rank test for the evolution of the indicators and Pearson and Spearman to establish correlations (p < 0.05). Results: The mean dose of tapentadol at one month and three months of treatment was lower in the group that received gabapentin in addition to tapentadol, followed by the group that also received pregabalin. In the tapentadol + gabapentin group, significant differences were observed between the groups in the reduction of DN4 after 1 and 3 months, and in the reduction of BPI after 1 month of treatment administration. This group also obtained a lower PGI-I than the rest of the groups, which was not statistically significant. Furthermore, significant differences appeared between the groups in activity and mood in favor of the group that, in addition to tapentadol, only received placebo. The side effect most frequently revealed by the study patients was dizziness and 9 patients abandoned the study because of it, but without significant differences between the four groups. Conclusion: A reduction in DN and an improvement in quality of life was observed after treatment with tapentadol alone or in association, with a certain synergism existing for the tapentadol+gabapentin association, also demonstrating a positive correlation DN4/Pain Detect used for the diagnosis of DN.