Fibromyalgia in Post Menopausal Women

A medication to help prevent osteoporosis and invasive breast cancer in post-menopausal women may also help those who have Fibromyalgia Syndrome (Fibro), according to a recently published study. [1]

The article, from a group of Iranian researchers, was published in the July edition of the European journal of internal medicine (e-published last November), and discusses a study looking at Raloxifene (Evista) in the treatment of Fibro.

Raloxifene is a type of medication called a selective oestrogen receptor modulator. It is licensed in the USA and UK for the treatment of osteoporosis in post-menopausal women and also for the prevention of invasive cancer in post-menopausal women who either have osteoporosis or are at high risk of invasive breast cancer. Raloxifene is not a form of Hormone Replacement Therapy (HRT), but is rather an oestrogen agonist/antagonist, which means that it works like oestrogen in some tissues in the body, and has the opposite effect in other tissues.

The double-blind randomized study was carried out from Feb 2005 until Oct 2006 and enrolled one hundred menopausal women with Fibro. Fifty study participants were given Raloxifen 60mg every other day over 16 weeks, with the other 50 being given a placebo. [1]

The primary outcome measure used was a mean score from: the Stanford Health Assessment Questionnaire (HAQ); the Iranian version of Hospital Anxiety and Depression questionnaire (IHAD); sleep disturbance; number of tender points; and the reduction of pain and fatigue based on Visual Analogue Score (VAS).

Forty-nine (98%) of the participants receiving Raloxifen and 47 (94%) of the participants receiving placebo completed the study. [1]

The study group taking the Raloxifen had a significantly higher response rate than the placebo group, with reduced pain and fatigue, reduced tender point count, reduced sleep disturbance and recovery of usual activities as measured by the Stanford Health Assessment Questionnaire (HAQ). No significant effect on the Hospital Anxiety and Depression questionnaire score was seen. [1]

The researchers concluded that:

"Raloxifen was superior to placebo in the treatment of menopausal patients with fibromyalgia." [1]

Anecdotal reports and some studies suggests that, although abnormalities in reproductive hormone levels are not associated with Fibro [2], the reproductive hormones may have an effect on Fibro symptoms, with the menopause worsening symptoms in some patients [3][4]. However, some studies have also suggested that the use of HRT, and specifically oestrogen HRT, may increase the risk of suffering from Fibro and other chronic pain conditions. [5][6][7] The selective modulation of oestrogen by Raloxifene, as opposed to the replacement of oestrogen by HRT, may be an important factor and could be a novel way of managing both some of the health risks associated with the menopause and also Fibro, in post-menopausal women with Fibromyalgia Syndrome.

References:

1. Sadreddini S, Molaeefard M, Noshad H, Ardalan M, Asadi A. Efficacy of Raloxifen in treatment of fibromyalgia in menopausal women. Eur J Intern Med. 2008 Jul;19(5):350-5. Epub 2007 Nov 28.
2. Samborski W, Sobieska M, Pieta P, Drews K, Brzosko M. Normal profile of sex hormones in women with primary fibromyalgia. Ann Acad Med Stetin. 2005;51(2):23-6.
3. Pamuk ON, Cakir N. The variation in chronic widespread pain and other symptoms in fibromyalgia patients. The effects of menses and menopause. Clin Exp Rheumatol. 2005 Nov-Dec;23(6):778-82.
4. Okifuji A, Turk DC. Sex hormones and pain in regularly menstruating women with fibromyalgia syndrome. J Pain. 2006 Nov;7(11):851-9.
5. Macfarlane TV, Blinkhorn A, Worthington HV, Davies RM, Macfarlane GJ. Sex hormonal factors and chronic widespread pain: a population study among women. Rheumatology (Oxford). 2002 Apr;41(4):454-7.
6. Benediktsdóttir B, Tómasson K, Gíslason T. [Climateric symptoms and hormone replacement treatment among 50 years old Icelandic women.] Laeknabladid. 2000 July/August;86(7/8):501-507.
7. Meisler JG. Chronic pain conditions in women. J Womens Health. 1999 Apr;8(3):313-20.