BALTIMORE — The anticonvulsant lamotrigine shows promise for reducing pain and improving mood symptoms associated with chronic pelvic pain, particularly in women with the vulvovaginal subtype.
In a study of 43 women with chronic pelvic pain, researchers at the University of North Carolina found that treatment with lamotrigine resulted in significant reductions in total pain, overall pain intensity, and depressive symptoms at 8 weeks, compared with baseline.
There were slightly greater reductions in those measures at 12 weeks that achieved significance. The study, which was presented as a poster at the annual meeting of the American Psychosomatic Society, was funded by GlaxoSmithKline Inc., maker of Lamictal (lamotrigine).
Dr. Samantha Meltzer-Brody of the department of psychiatry at the University of North Carolina, Chapel Hill, and her colleagues recruited women from a tertiary care clinic. Participants had to have pelvic pain for at least 6 months. Women were excluded if they had active systemic disease or substance abuse, pelvic surgery in the previous 6 months, or initiation/change in psychiatric medications in the previous month.
After baseline assessments, the women were titrated up to a therapeutic dosage of 400 mg/day lamotrigine over 8 weeks. This dosage was continued for weeks 8–12. Patients then were slowly discontinued from the drug over a 2-week period. A total of 31 women completed the 8-week titration phase and 21 completed all 12 weeks of treatment. Patients completed the McGill Pain Scale at each visit. Patients were also administered the Hamilton Depression Rating Scale.
The women completing 8 weeks of treatment were aged 41 years on average and were predominantly white (95%). The average dosage in that period was 340 mg/day. Most of the women had the vulvodynia/vulvar vestibulitis syndrome subtype (17). The remaining women were evenly split between diffuse abdominal pain (7) and neuropathic pain (7).
The researchers also analyzed the data by chronic pelvic pain subtype. Those with the vulvovaginal pain subtype (VVS) had significant reductions in McGill total pain and visual analog scale overall pain intensity scores at weeks 8 and 12. They also had a significant reduction in Hamilton Depression Rating Scale scores at 12 weeks. However, the investigators noted in the poster that “VVS patients have better mental health and decreased rates of sexual and/or physical abuse history compared to women with other chronic pelvic pain subtypes.”