Neurotropin Treatment of Fibromyalgia

Fibromyalgia is a relatively common disorder, which occurs predominantly in women, that is characterized by widespread aching and stiffness in muscles. Although there have been numerous studies of fibromyalgia, its etiology has remained unclear, but it is generally believed that central pain processing abnormalities are involved. Neurotropin, a non-protein extract of inflamed cutaneous tissue from rabbits inoculated with vaccinia virus, has been used extensively in Japan for many years to treat a variety of chronic painful conditions, including fibromyalgia. This present protocol is a double blind, placebo-controlled, crossover study designed to examine the clinical efficacy of Neurotropin in treating women (neither pregnant nor lactating) suffering from fibromyalgia without evidence of any other cause of their complaint of pain. Patients must meet the American College of Rheumatology (ACR) diagnostic criteria for fibromyalgia and must agree to maintain a stable therapeutic regimen throughout the 25-week study.

Inclusion criteria

Subjects will be drawn from a cohort of well-characterized female fibromyalgia patients who were under the care of Dr. Daniel. J. Clauw when he was at Georgetown University. All patients must continue to meet the criteria established by the ACR for diagnosis of fibromyalgia, and must have been treated unsuccessfully with a current standard therapeutic regimen. The criteria are (A) a history of widespread pain (in all quadrants and back) for more than half of the days in each of the prior three months and (B) the required number,11, of tender points of 18 test sites (indicated in Figure 1), which will be determined during the initial physical examination (see below). They must give informed consent to participate in this study. It is anticipated that almost all patients will be residents of Washington, D.C. area and that they will be able to travel to NIH for necessary preliminary studies and subsequent required evaluations. To be admitted to this study, patients must be willing to continue using only their present medications (including antidepressants) or other forms of care related to the control of fibromyalgia symptoms during the course of the study. The average score on the FIQ for patients seen in tertiary care settings is about 50 (with 100 being the maximum, a higher score indicating a greater impairment of health) and we will include only those patients in whom the FIQ score is greater than 30 at the initial evaluation.

Exclusion criteria

Pregnant and lactating women are excluded because of the bodily changes that would occur during the study. As indicated above, a pregnancy test will be performed in women of childbearing age (up to age 55). The combination of widespread musculoskeletal pain, high tender point count, and non-restorative sleep are usually sufficient criteria for the diagnosis of fibromyalgia and the patients referred for this study will have been well characterized in the Fibromyalgia Clinic at Georgetown University or by the referring physician. We will, however, by history, physical examination, screening laboratory studies and examination of the patient s medical records confirm the absence of any evidence for peripheral neuropathies, entrapment syndromes, neurologic disorders or metabolic/endocrine disorders, such as untreated hypothyroidism, as well as the rheumatoid disorders that might be confused with fibromyalgia and confound the study. Patients who have abnormal screening test results or who have traumatic or non-traumatic disorders to which pain may be attributed. Also, patients who have a positive HIV result will be excluded. Subjects with obviously impaired mental capacity that precludes informed consent and ability to provide adequate self-ratings are to be excluded.