Vulvar vestibulitis trial: Desipramine-Lidocaine

点击翻译按钮获取中文摘要

DESCRIPTION (provided by applicant): Studies are proposed for the subtype of vulvodynia known as vulvar vestibulitis. The first major aim of this application is to conduct a randomized, placebo-controlled, double-blinded clinical trial to study the clinical efficacy of four medical regimens: topical lidocaine, oral desipramine, topical lidocaine combined with oral desipramine and placebo. The efficacy of standard treatments for vulvar vestibulitis proven by randomized, placebo-controlled, blinded clinical trials has not been assessed. The tricyclic class of antidepressants, represented by desipramine, have gained empiric acceptance for the treatment of vulvar vestibulitis, although favorable therapeutic results have been reported by only a few retrospective studies or uncontrolled clinical trials. Although the precise mechanism of action remains undefined for tricyclic antidepressants, a "central" action through the dorsal horn and brain stem has been suggested. In contrast to oral desipramine, the long-term, topical application of lidocaine may act through a "local" mechanism. This randomized, placebo-controlled, double-blinded clinical trial is designed to determine whether "local" or "centrally-acting" treatments alone, or in combination are efficacious in treating vulvar vestibulitis. Outcome measures of success will include reduced overall pain, reduced pain to touch, reduced pain to standardized mechanical stimuli, increased pain-free intercourse, improved sexual function, improved quality-of-life as measured by psychometric tests, and adherence to active drug regimens. The second major aim of this application is to study the relationship among genetic polymorphisms of the IL-1 Receptor Antagonist locus, tissue levels of pro-inflammatory cytokines, and response to treatment of vulvar vestibulitis. Pro-inflammatory cytokines, such as interleukin-I beta (IL-1 beta) and tumor necrosis factor alpha (TNF-alpha), are secreted from a local cellular source and accumulate above normal levels in the region of the hymeneal ring. Recent genetic analysis finds a 53% homozygosity for allele 2 IL-1 Receptor Antagonist (IL-1 RA*2) in cases of vulvar vestibulitis, in contrast to 8.5% homozygosity in asymptomatic women. Furthermore, the IL-1 RA*2 allele has been linked to increased production of IL-1 beta in vitro. In our second aim, we will determine whether these in vitro results can be extrapolated to clinical cases of vulvar vestibulitis. Using samples from our clinical trial, we will assess the relationship between homozygosity for IL-1 RA*2, tissue levels of IL-1 beta, and TNF-alpha, and response to treatment. In summary, this project will allow us to answer several important questions about vulvar vestibulitis. Is medical treatment effective? Is centrally-acting or locally-acting treatment equally effective or is one superior to the other? Is there any benefit from combined local and systemic treatments? And finally, do genetic characteristics and tissue cytokine concentrations influence treatment response?