Gabapentin ineffective for chronic pelvic pain in women

  • Horne AW & al.
  • Lancet
  • 26 Sep 2020

  • curated by Sarfaroj Khan
  • UK Clinical Digest
Access to the full content of this site is available only to registered healthcare professionals. Access to the full content of this site is available only to registered healthcare professionals.

Takeaway

  • Treatment with gabapentin did not result in significantly lower pain scores in women with chronic pelvic pain and no obvious pelvic pathology.
  • Gabapentin was associated with higher rates of side effects than placebo.

Why this matters

  • Given the rising reports of abuse and evidence of potential harms associated with gabapentin, physicians should consider alternative treatment options to off-label gabapentin for the management of chronic pelvic pain and no obvious pelvic pathology.

Study design

  • In this multicentre double-blind, placebo-controlled randomised trial (GaPP2) conducted across 39 UK hospital centres, 306 women with chronic pelvic pain and no obvious pelvic pathology were randomly assigned in a ratio 1:1 to receive gabapentin or matching placebo for 16 weeks.
  • Dual primary outcome measures of worst and average pain scores were recorded on a numerical rating scale (NRS) at 13-16 weeks after randomisation.
  • Funding: National Institute for Health Research.

Key results

  • No significant between-group differences were seen in both worst and average NRS pain scores at 13-16 weeks.
  • The mean worst NRS pain score was 7.1 (standard deviation [SD], 2.6) and 7.4 (SD, 2.2) in the gabapentin and placebo groups, respectively.
  • Mean change from baseline was –1.4 (SD, 2.3) and –1.2 (SD, 2.1) in the gabapentin and placebo groups, respectively (adjusted mean difference, –0.20; 97.5% CI, –0.81 to 0.42; P=.47).
  • The mean average NRS pain score was 4.3 (SD, 2.3) in the gabapentin group vs 4.5 (SD, 2.2) in the placebo group.
  • Mean change from baseline was –1.1 (SD, 2.0) and –0.9 (SD, 1.8) in the gabapentin and placebo group, respectively (adjusted mean difference, –0.18; 97.5% CI, –0.71 to 0.35; P=.45).
  • Serious adverse events were higher in the gabapentin vs placebo group (7% vs 2%).
  • Dizziness, drowsiness, and visual disturbances were more common with gabapentin vs placebo.

Limitations

  • Relatively small sample size.