- 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.
- 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.
- 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.
- Relatively small sample size.