Evidence-based Traditional Chinese Medicine therapies for Dysmenorrhea (Sun Ten Journal NO. 8, Mar 2007, Page56-59)

Evidence-based Traditional Chinese Medicine Therapies for Dysmenorrhea

Dysmenorrhea, painful menstruation, is a common women's disorder. This is also one of the common causes of teenage girls or young women's absence from school or work. According to a survey conducted in Sweden, 72% of 19-year-old girls had dysmenorrhea, which resulted in limitation of daily activities. Dysmenorrhea also causes financial losses. From an early report, dysmenorrhea was associated with annual productivity loss of 600 million work hours, and financial losses of up to $2 billion dollars. Mostly, those who suffered from dysmenorrhea choose non-steroidal anti-inflammatory drugs (NSAIDs) as their first option of treatment. Besides, oral contraceptives are also commonly used for dysmenorrhea as a conventional therapy. However, the patients who do not have response to the conventional treatment or who have side effects from the conventional therapy may seek alternative therapy. Traditional Chinese medicine (TCM) therapies, which have been practiced for more than two thousand years in China, are becoming more popular in the west in recent years. How is the effectiveness of traditional Chinese medicine (TCM) therapies for dysmenorrhea? How does it work? Lately, some clinical studies were conducted to investigate the efficacy and the mechanism of TCM treatment for dysmenorrhea.

Dysmenorrhea can be classified into primary and secondary dysmenorrhea. Primary dysmenorrhea is defined as painful menstruation associated with normal pelvic anatomy. Whereas, secondary dysmenorrhea is defined as painful menses associated with pelvic pathology, for example, endometriosis (the presence of endometrial tissues outside uterine cavity). Most patients are categorized into primary dysmenorrhea. The typical clinical presentation is characterized by cyclic pelvic pain before or at the onset of periods, frequently associated with blood clots, in a woman in her 2nd to 4th decades.

According to the traditional Chinese medicine, the pathogenesis of dysmenorrhea may be caused by negative emotions (such as anger, or emotional stress), cold and dampness invasion, over-exertion or chronic illness.

Based on patients' clinical manifestations including menstrual history, symptoms, and tongue and pulse findings, the patterns of dysmenorrheal patients are identified as excess or deficiency, heat or cold, or combined. Most patients are categorized into the one the following patterns or combinations: qi stagnation and blood stasis, excess cold congealment, dampness-heat accumulation, qi and blood deficiency, yang deficiency with cold, kidney and liver deficiency. Different formulas will be subscribed for different patterns. The commonly used formulas include “Rambling Powder” (xiao yao san), “Four substance Decoction with Safflower and Peach Pit” (tao hong si wu tang), “Drive Out Blood Stasis Below the Diaphragm Decoction“(ge xia zhu yu tang), “Drive Out Blood Stasis in the Lower Abdomen Decoction” (shao fu zhu yu tang), “Warm the Menses Decoction” (wen jing tang), and “Regulate Liver Decoction” (tiao gan tang).

In TCM theory, the penetrating vessel (chong mai) and directing vessel (ren mai) are essential to the regular and smooth menstruation because both vessels originate from the kidneys and the kidneys are closely related to the uterus. Disharmony between chong mai and ren mai is thought to be one of the causes of dysmenorrhea. A study in 2004 reported lower electrical conduction volume on LU7 (lieque), the confluent point of ren mai, and higher electrical conduction volume on SP4 (gongsun), the confluent point of chong mai, was found among dysmenorrheal patients than the non-dysmenorrheal group on their first day of menstruation.

How does the acupuncture work in the treatment of dysmenorrhea? Is it due to the local effect or through a central mechanism? To investigate the mechanism of acupuncture, one study showed that acupuncture at right-sided SP6 (saninjiao) activated the pain-related brain areas on the same side, opposite side, or both sides of six dysmenorrheal patients. These changes were detected by positron emission tomography (PET).

How does the herbal formula work? In western medicine, dysmnoerrhea is thought to be caused by an increased release of prostaglandin F2 £, which is secreted from the uterine endocmetrium. A variety of formulas have been used for treatment of dysmenorrhea. “ Warm menses decoction” (wen jing tang), one of the most commonly used herbal formula for dysmenorrhea, has been reported to suppress the PGF 2£ –induced uterine contractions of rats in vitro. Interestingly, this formula had no effect on spontaneous contractions of rats' uterine myomtrium.

Regarding the evidence-based acupuncture studies, a clinical research report of 30 dysmenorrheal patients in 2003 showed acupuncture treatment on Du20 (baihui), LI4 (hegu), Ren3 (zhongji), Ren4 (guanyuan), Ren6 (qihai), GB34 (yanglingquan), UB23 (shenshu), SP6 (sanyinjiao), and Shenmen was more effective than the placebo (pseudo-acupuncture) group (by superficial intracutaneous acupuncture without “de qi”). One earlier clinical study in 1987 also reported patients receiving real acupuncture on SP4 (gongsun), K3 (taixi), ST36 (zusanli), ST30 (qichong), Ren2 (qugu), Ren4 (guanyuan), and Ren6 (qihai) had better improvement rate than the non-acupoint acupuncture group in a one-year follow-up period. Acupressure is a non-invasive technique, which is commonly used in self-care. A clinical study in 2002 reported, among 216 high school adolescents with dysmenorrhea, acupressure was as effective as the ibuprofen (a non-steroidal anti-inflammatory drug) in pain reduction.

Another question regarding acupuncture may be raised: “Is there any difference in clinical efficacy between different acupuncture prescriptions?” A clinical study involving 60 patients divided primary dysmenrorheal patients into three groups: 1.back-Shu & front –Mu acupuncture group with acupoints of UB 18 (ganshu), UB20 (pishu), UB23 (shenshu), Ren3 (zhonji), Ren4 (guanyuan), ST25 (tianshu) and Du20 (baihui) , 2.conventional acupuncture group with acupoints of Ren4 (guanyuan), Ren6 (qihai), SP6 (sanyinjiao), SP8 (Diji), ST36 (zusanli), LV3 (taichong), LI4 (hegu), and 3. Western medicine group with an analgesics. It was found that the “back-Shu & front-Mu” group was superior to the conventional acupuncture group and western medicine group.

Recently, a variety of herbal formulas have been used to evaluate the clinical efficacy in the treatment of dysmenorrhea. In a clinical trial,primary dysmenorrheal patients with the patterns of “cold, deficiency, yin and blood stasis”
were treated with either “Toki-shakuyaku-san” (dang gui shao yao san) or placebo pills. During the 2-menstrual-cycle treatment period, improvement of the dysmenorrheal pain was observed in both groups, but it was better in the herbal group. The herbal group even had a significant reduction in the consumption of analgesics in the 2-menstrual-cycle follow-up period. Additionally, a single herb, rose, is thought to have the anxiolytic effect by “regulating the liver qi”. One study of 130 female adolescents with primary dysmenorrhea showed that the patients who drank rose tea had less menstrual pain and anxiety as compared with control group. Besides, some other clinical trials were conducted to compare the clinical efficacy of Chinese herbal medicine to western medicine. In two studies, the herbal group was given with the basic herbal formula with modifications according to the patient's patterns. In the other two, the treatment group was treated with a fixed herbal formula. In all these studies, the improvement rate is higher than 90% and superior to western medicine (analgesics) group.

Other therapies including moxibustion, auricular point pressing and tui-na massage were also studied. Moxibustion is a special TCM therapy that applies heat by burning specific herbs on certain acupuncture points to warm up meridians, and expel the cold. In a trial involving 40 dysmenorrheal patients with deficiency pattern, moxibustion was randomly given on either LU7 (lieque) or Ren 4 (guanyuan). The pain improved in both groups, but there was no difference in the improvement rate in both groups. In auricular point pressing, a clinical trial reported that improvement was observed in both auricular pint pressing group and acupuncture group. No difference in improvement rate was found between both groups. For Tui-na massage, in a clinical study, tui-na massage was applied to 62 patients with primary dysmenorrhea on back- shu points, lower back, “Penetrating vessel” (ren mai), lower abdominal points and ST 36 (zusanli), SP 6 (sanyinjiao), and SP 10 (xuehai). The controlled group was treated with “qu tong pian” (an analgesics). The result showed that the tui-na massage group experienced more pain relief and was superior to the western medicine group.

Combined treatment with two or three different modalities is common in the clinical setting of traditional Chinese medicine clinic. In four studies identified, the combined treatment group had a better response than the single modality. The improvement rates of the groups with combined therapies ranged from 95.38% to 98.5%. The studies included the herbal medicine combined with acupuncture versus indomethacin, herbal formula plus acupuncture versus herbal formula only, acupuncture plus moxibustion versus herbal medicine, and acupuncture with moxibustion versus herbal medicine.

Conclusively, most clinical studies of TCM therapies for dysmenorrhea showed promising results. These studies showed that acupuncture, herbal therapy or other modality is more effective than or as effective as the control or placebo group. Combined therapies showed better result than single modality. Hence, TCM is a valuable alternative treatment for dysmenorrhea. However, many studies were not well-designed. Hence, comprehensive and well-designed clinical trials in TCM

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