Gabapentin has Longer-Term Efficacy for the Treatment of Chronic Pelvic Pain in Women: A Systematic Review and Pilot Meta-analysis

Abstract

Introduction: Gabapentin has potential analgesic benefits in patients with neuropathic pain, such as post-herpetic neuralgia and diabetic peripheral neuropathy neuropathic pain. However, its efficacy in women with chronic pelvic pain (CPP) remains contradictory. In the present study, we performed a systematic review and meta-analysis of randomized controlled trials (RCTs) to ascertain the efficacy of this treatment. Methods: We systematically reviewed RCTs published in PubMed, Embase, the Cochrane Library, Web of Science, and Google Scholar databases, up to July 2021. These articles compared gabapentin with placebo or any other active treatment for CPP in women, with 'the change in pain scores from the baseline during the first 3 and 6 months of treatment' taken as the primary outcome. We considered reductions equivalent to 1.0 cm for primary outcomes to be clinically important. Results: Four studies, comprising 469 participants, were included in our meta-analysis. Results revealed that the gabapentin group had significantly higher change in pain intensity scores from baseline to 3 months [weighted mean difference (WMD) -0.61 cm; 95% confidence interval (CI) -0.97 to -0.25; I 2 = 0%; p = 0.0009] and 6 months (WMD -1.38 cm; 95% CI -1.89 to -0.88; I 2 = 0%; p \ 0.00001), relative to the control group. The difference of 6-month pooled result was more clinically important. Results from analysis of secondary outcomes showed that gabapentin had no beneficial efficacy during the first 3 months of treatment. Although gabapentin treatment was associated with a higher risk of dizziness and somnolence, no statistically significant differences were observed with regards to the total incidence of adverse events. Conclusions: Overall, gabapentin could be a potential treatment option for CPP in women. However, as a pilot study, further studies are needed to explore the longer-term benefits and definite safety of this therapy in the future.Xiu-Mei Fan and Yi-Feng Ren contributed equally as co-first authors.

A Response to: Letter to the Editor Regarding “Gabapentin has Longer-Term Efficacy for the Treatment of Chronic Pelvic Pain in Women: A Systematic Review and Pilot Meta-analysis”

“…The results showed that neither including nor excluding the trial of Horne et al had a significant alteration for the primary outcomes (see Table 1 ). Besides, it is noteworthy that our results [ 1 ] are consistent with those from Lewis et al, 2016, which conducted by their team [ 3 ]. Similarly, Putzke and colleagues also found that gabapentin had a longer-term analgesic effect (3 years) for pain after traumatic spinal cord injury [ 4 ].…”

“…Thank you for informing us about the letter discussing the results of “Gabapentin has Longer-Term Efficacy for the Treatment of Chronic Pelvic Pain in Women: A Systematic Review and Pilot Meta-analysis” [ 1 ]. Meanwhile, we also appreciate the comments by Vincent et al about our research.…”

“…Third, we agree with Vincent et al that there is a risk of gabapentin-related adverse events in the treatment of CPP in women. As such, we also suggested that ‘patients with major neurologic conditions are advised to avoid gabapentin-based treatment’ in the discussion section of the paper [ 1 ]. Additionally, Horowitz et al also showed that further studies were needed to assess the long-term efficacy and safety of gabapentin for patients with anxiety and other mental health conditions [ 10 ].…”

Current Challenges in the Management of Chronic Pelvic Pain in Women: From Bench to Bedside

“…A systematic review that included four randomized controlled trials and 469 participants showed that the anticonvulsant gabapentin reduced CPP in women after six months of use, with the principal side effects being dizziness and somnolence. 145 In a Cochrane review that included 45 studies and 11,906 participants, pregabalin reduced pain by at least 30% in patients with diabetic and post-herpetic neuropathy at a dose of 300 mg/day and in patients with post-traumatic neuropathic pain, whether classified as mixed or not, at a dose of 600 mg/day, with similar side effects to those found with gabapentin. 146 Extrapolating these data, pregabalin could be recommended for the treatment of CPP.…”

Letter to the Editor Regarding “Gabapentin has Longer-Term Efficacy for the Treatment of Chronic Pelvic Pain in Women: A Systematic Review and Pilot Meta-analysis”

“…We were concerned to read the article entitled “Gabapentin has Longer-Term Efficacy for the Treatment of Chronic Pelvic Pain in Women: A Systematic Review and Pilot Meta-analysis”, published recently by Fan and colleagues [ 1 ], which concluded that gabapentin could be a potential treatment option for chronic pelvic pain in women. We believe that the methodology used in this systematic review is inappropriate, and thus draws erroneous conclusions with the potential to expose women with chronic pelvic pain to unnecessary risk.…”