Is gabapentin effective for women with unexplained chronic pelvic pain?

Horne, Andrew; Vincent, Katy; Cregg, Roman; Daniels, Jane

doi:10.1136/bmj.j3520

Cited by 9 publications

(11 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3 Management of chronic pelvic pain within gynaecological practice is difficult as no established treatments are available, but careful exploration of symptoms and history can point to non-gynaecological causes of chronic pelvic pain, for which some effective treatments exist. 4 The off-label use of gabapentin for chronic pelvic pain has increased because of its proven efficacy in other chronic pain conditions. 5,6 Gabapentin primarily affects modulation of pain by the CNS, and neuroimaging studies have shown gabapentinoids affect brain function in models of central sensitisation and in patients with chronic pain.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Gabapentin for chronic pelvic pain in women (GaPP2): a multicentre, randomised, double-blind, placebo-controlled trial

et al. 2020

Self Cite

View full text Add to dashboard Cite

Background Chronic pelvic pain affects 2-24% of women worldwide and evidence for medical treatments is scarce. Gabapentin is effective in treating some chronic pain conditions. We aimed to measure the efficacy and safety of gabapentin in women with chronic pelvic pain and no obvious pelvic pathology. Methods We performed a multicentre, randomised, double-blind, placebo-controlled randomised trial in 39 UK hospital centres. Eligible participants were women with chronic pelvic pain (with or without dysmenorrhoea or dyspareunia) of at least 3 months duration. Inclusion criteria were 18-50 years of age, use or willingness to use contraception to avoid pregnancy, and no obvious pelvic pathology at laparoscopy, which must have taken place at least 2 weeks before consent but less than 36 months previously. Participants were randomly assigned in a 1:1 ratio to receive gabapentin (titrated to a maximum dose of 2700 mg daily) or matching placebo for 16 weeks. The online randomisation system minimised allocations by presence or absence of dysmenorrhoea, psychological distress, current use of hormonal contraceptives, and hospital centre. The appearance, route, and administration of the assigned intervention were identical in both groups. Patients, clinicians, and research staff were unaware of the trial group assignments throughout the trial. Participants were unmasked once they had provided all outcome data at week 16-17, or sooner if a serious adverse event requiring knowledge of the study drug occurred. The dual primary outcome measures were worst and average pain scores assessed separately on a numerical rating scale in weeks 13-16 after randomisation, in the intention-to-treat population. Self-reported adverse events were assessed according to intention-to-treat principles. This trial is registered with the ISRCTN registry, ISCRTN77451762. Findings Participants were screened between Nov 30, 2015, and March 6, 2019, and 306 were randomly assigned (153 to gabapentin and 153 to placebo). There were no significant between-group differences in both worst and average numerical rating scale (NRS) pain scores at 13-16 weeks after randomisation. The mean worst NRS pain score was 7•1 (standard deviation [SD] 2•6) in the gabapentin group and 7•4 (SD 2•2) in the placebo group. Mean change from baseline was-1•4 (SD 2•3) in the gabapentin group and-1•2 (SD 2•1) in the placebo group (adjusted mean difference-0•20 [97•5% CI-0•81 to 0•42]; p=0•47). The mean average NRS pain score was 4•3 (SD 2•3) in the gabapentin group and 4•5 (SD 2•2) in the placebo group. Mean change from baseline was-1•1 (SD 2•0) in the gabapentin group and-0•9 (SD 1•8) in the placebo group (adjusted mean difference-0•18 [97•5% CI-0•71 to 0•35]; p=0•45). More women had a serious adverse event in the gabapentin group than in the placebo group (10 [7%] of 153 in the gabapentin group compared with 3 [2%] of 153 in the placebo group; p=0•04). Dizziness, drowsiness, and visual disturbances were more common in the gabapentin group. Interpretation This study was adequately...

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Gabapentin for chronic pelvic pain in women (GaPP2): a multicentre, randomised, double-blind, placebo-controlled trial

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…The multicentre placebo-controlled RCT described here aims to contribute to the evidence base by assessing the efficacy of gabapentin in women with CPP with no underlying pathology. 9 This trial is designed in line with the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials (IMMPACT) recommendations for the design of trials in chronic pain conditions 21 27 28 and builds on a successful pilot study. 11 12 Women with CPP were surveyed to identify whether reduction in average or worst pain was most important to them.…”

Section: Discussionmentioning

confidence: 99%

“… 8 However, there is no good quality evidence in CPP specifically on which to base this practice. 9 To our knowledge, there is only one study evaluating the use of gabapentin for CPP, which did not have a placebo arm. 10 This small study in 56 women, compared gabapentin with amitriptyline and showed gabapentin to have greater efficacy at improving pain scores at 12 months.…”

Section: Introductionmentioning

confidence: 99%

GaPP2, a multicentre randomised controlled trial of the efficacy of gabapentin for the management of chronic pelvic pain in women: study protocol

et al. 2018

View full text Add to dashboard Cite

IntroductionChronic pelvic pain (CPP) affects more than 1 million UK women with associated healthcare costs of £158 million annually. Current evidence supporting interventions when no underlying pathology is identified is very limited and treatment is frequently inadequate. Gabapentin (a GABA analogue) is efficacious and often well tolerated in other chronic pain conditions. We have completed a successful pilot randomised controlled trial Gabapentin for Pelvic Pain 1 (GaPP1) and here describe the protocol for our definitive multicentre trial to assess the efficacy of gabapentin in the management of CPP in women Gabapentin for Pelvic Pain 2 (GaPP2).Methods and analysisWe plan to perform a double-blind placebo-controlled randomised multicentre clinical trial, recruiting 300 women with CPP from up to 40 National Health Service hospitals within the UK. After randomisation, women will titrate their medication (gabapentin or placebo) over a 4-week period to a maximum of 2700 mg or placebo equivalent and will then maintain a stable dose for a 12-week period. Response to treatment will be monitored with validated questionnaires and coprimary outcome measures of average and worst pain scores will be employed. The primary objective is to test the hypothesis that treatment with gabapentin has the potential to provide an effective oral treatment to alleviate pain in women with CPP in the absence of any obvious pelvic pathology.Ethics and disseminationEthical approval has been obtained from the Coventry and Warwick Research Ethics Committee (REC 15/WM/0036). Data will be presented at international conferences and published in peer-reviewed journals. We will make the information obtained from the study available to the public through national bodies and charities.Trial registration numberISRCTN77451762; Pre-results.

show abstract

“…Second, with the support of the Royal College of Obstetricians and Gynaecologists, we surveyed a random group of gynaecologists and 50% said that they currently prescribe gabapentin for CPP, and > 90% said that they would consider gabapentin as a treatment option for this condition. Since then, awareness and use of gabapentinoids has continued to increase in gynaecology, with the publication of reviews in this area 17 and reference within the National Institute for Health and Care Excellence (NICE) guideline for endometriosis 18 to the NICE guideline on neuropathic pain for treatment of CPP with neuromodulators. 19 This was despite the fact that there was no good-quality evidence of efficacy in CPP specifically on which to base this practice, and the fact that these drugs were not licensed for CPP.…”

Section: Drugs Targeting Central Pain Mechanismsmentioning

confidence: 99%

Gabapentin to reduce pain in women aged between 18 and 50 years with chronic pelvic pain: the GaPP2 RCT

et al. 2020

Self Cite

View full text Add to dashboard Cite

Background Chronic pelvic pain affects 2–24% of women worldwide, and evidence for medical treatments is limited. Gabapentin is effective in treating some chronic pain conditions, but its effect on central pain processing is unknown. Objectives To test the hypothesis that gabapentin can reduce pain and improve physical and emotional functioning in women with chronic pelvic pain. We investigated the mechanism of action of gabapentin in a subset of women. Design A randomised, double-blind, placebo-controlled, multicentre trial with a brain imaging substudy. Setting This trial took place in 39 UK hospitals. Participants A target of 300 women with a history of chronic pelvic pain in whom a laparoscopy revealed no obvious pelvic pathology. Intervention Women were randomised to receive 300 mg of gabapentin (which was escalated to a maximum of 2700 mg daily) or a matched placebo over a 4-week dose-escalation period, followed by 12 weeks on optimal dose. A mechanistic substudy was also undertaken, in which a subset of participants had a functional magnetic resonance imaging scan of their brain before and following 16 weeks of treatment. Main outcome measures The dual primary measure of the worst and average pelvic pain scores was assessed weekly by a numerical rating scale (0–10) in weeks 13–16 post randomisation. The secondary outcomes were patient-reported questionnaires, assessed physical functioning, fatigue, psychological health, sexual activity, work and productivity, and pain catastrophising. Health-care resource use, analgesic use and adverse events were also collected. The main outcome measure for the mechanistic study was brain activity at rest and in response to noxious stimuli. Results In the main trial, 306 participants were randomised. The mean worst pain score was 7.1 (standard deviation 2.6) in the gabapentin group and 7.4 (standard deviation 2.2) in the placebo group (adjusted mean difference –0.20, 97.5% confidence interval –0.81 to 0.42; p = 0.47). The mean average pain score was 4.3 (standard deviation 2.3) in the gabapentin group and 4.5 (standard deviation 2.2) in the placebo group (adjusted mean difference –0.18, 97.5% confidence interval –0.71 to 0.35; p = 0.45). No significant between-group differences were observed for any secondary outcome. A higher proportion of women experienced a serious adverse event in the gabapentin group than in the placebo group (10/153 vs. 3/153; p = 0.04). Dizziness, drowsiness and visual disturbances were more common in the gabapentin group than in the placebo group. In the mechanistic study, 45 participants had a baseline functional magnetic resonance imaging scan of their brain, with 25 participants returning for a scan at the end of treatment. Gabapentin significantly decreased evoked activity in the anterior cingulate cortex and cuneus. Change in anterior cingulate cortex activity after treatment related to improvement on the pain interference scale, and baseline activation of this region predicted response to treatment. Conclusions Gabapentin did not reduce pain and did not improve other outcomes compared with placebo over 16 weeks. Serious adverse effects were significantly higher in the gabapentin group than in the placebo group. Gabapentin reduces evoked activity in the anterior cingulate cortex, with changes of activity in this region tracking reported pain, and baseline activity predicting response to treatment. Limitations Primary outcome data were unavailable in 62 and 60 women for the average and worst numerical rating scale pain scores, respectively. A sensitivity analysis using imputation methods did not change the result. Future work Clinical trials to investigate other pharmacological interventions (monotherapy vs. combination therapy), physiotherapy and cognitive–behavioural therapy to treat women with chronic pelvic pain are needed. Trial registration Current Controlled Trials ISRCTN77451762 and EudraCT 2014-005035-13. Funding This project was funded by the Efficacy and Mechanism Evaluation (EME) programme, a Medical Research Council and National Institute for Health Research (NIHR) partnership. This will be published in full in Efficacy and Mechanism Evaluation; Vol. 7, No. 7. See the NIHR Journals Library website for further project information.

show abstract

Is gabapentin effective for women with unexplained chronic pelvic pain?

Cited by 9 publications

References 3 publications

Gabapentin for chronic pelvic pain in women (GaPP2): a multicentre, randomised, double-blind, placebo-controlled trial

Gabapentin for chronic pelvic pain in women (GaPP2): a multicentre, randomised, double-blind, placebo-controlled trial

GaPP2, a multicentre randomised controlled trial of the efficacy of gabapentin for the management of chronic pelvic pain in women: study protocol

Gabapentin to reduce pain in women aged between 18 and 50 years with chronic pelvic pain: the GaPP2 RCT

Contact Info

Product

Resources

About