RESUMO
BACKGROUND: Chronic pelvic pain (CPP) is a frequent presenting symptom in gynaecology outpatient clinics. Neuromodulator pharmacological agents could be an option for treatment based on its efficacy in treating chronic pain in other conditions. PURPOSE: This study aimed at evaluating the efficacy of oral Gabapentin to alleviate pain in women with CPP. METHODS: In a randomized double-blinded placebo-controlled trial, 60 women suffering from chronic pelvic pain were randomly divided into two equal arms. The study group received Gabapentin 300 mg three times daily initially (900 mg), with 300 mg weekly incremental dose till pain was controlled, severe side effects occurred or maximum daily dose of 2700 mg was reached. The Primary outcome was the pain score improvement of CPP, defined as a 30% reduction in the pain score assessed by the 10-cm Visual Analogue Scale compared to baseline score. RESULTS: In Gabapentin group, pain was significantly reduced at 12 and 24 weeks (mean = 5.12 ± 0.67 and 3.72 ± 0.69, respectively) than in placebo group (mean = 5.9 ± 0.92 and 5.5 ± 1.13, respectively); this difference was significant. At 24 weeks, there was significantly higher proportion of patients reporting 30% or more reduction in pain scores; 19 out of 20 patients (95%) in Gabapentin group compared to 8 out of 14 patients (57.1%) in placebo group. The relative risk for pain after gabapentin treatment was 0.5 with 95% confidence interval = 0.34 to 0.75 and number needed to treat = 3 (p = 0.007). Regarding adverse effects there was significantly higher incidence of dizziness with Gabapentin (26.1%) compared to placebo (3.3%). CONCLUSION: Chronic pelvic pain in women may be treated sufficiently with Gabapentin. TRIAL REGISTRATION: The trial was registered in ClinicalTrials.gov registry with clinical trial registration number: NCT02918760.