Medi

cinaENDOMETRIOSIS Low-dose oral contraceptive pill for dysmenorrhea associated with endometriosis: a placebo-controlled, double-blind, randomized trial
Tasuku Harada, M.D.,a Mikio Momoeda, M.D.,b Yuji Taketani, MD.,b Hiroshi Hoshiai, M.D.,c and Naoki Terakawa, M.D.a
Department of Obstetrics and Gynecology, Tottori University School of Medicine, Yonago, Japan; b Department of Obstetrics andGynecology, Tokyo University, Tokyo, Japan; and c Department of Obstetrics and Gynecology, Kinki University, Osaka, Japan
a

Objective: To evaluate the efficacy of a low-dose oral contraceptive pill (OCP) for patients with dysmenorrhea associated with endometriosis. Design: A double-blind, randomized, placebo-controlled trial. Settings: Clinical trial sites in Japan. Patient(s): One hundredpatients with dysmenorrhea associated with endometriosis. Most enrolled patients had radiologic evidence of endometriosis rather than surgical diagnosis. Intervention(s): Patients were randomly assigned to receive either monophasic OCP (ethinylestradiol plus norethisterone) or placebo. Participants used their usual pain medications as needed during the trial. Main Outcome Measure(s): After four cyclictreatments, we used a zero- to three-point verbal rating scale and a visual analogue scale to measure the severity of disability because of dysmenorrhea in daily life, and the patients’ use of analgesics. Result(s): Total dysmenorrhea scores assessed by the verbal rating scale were significantly decreased at the end of treatment in both groups. From the first cycle through the end of treatment,dysmenorrhea in the OCP group was significantly milder than in the placebo group. Nonmenstrual pelvic pain was present at baseline in 24.5% (12 of 49) of the OCP group and 34.0% (16 of 47) of the placebo group. The volume of endometrioma (larger than 3 cm in diameter) was significantly decreased in the OCP group, but not in the placebo group. No serious adverse events related to using OCPs occurred.Conclusion(s): The present study clearly demonstrated for the first time that OCPs could be used to effectively and safely treat pain associated with endometriosis. (Fertil SterilÒ 2008;90:1583–8. Ó2008 by American Society for Reproductive Medicine.) Key Words: Oral contraceptive (OC), ethinylestradiol, norethisterone, randomized clinical trial

Endometriosis, a chronic gynecologic disease, ischaracterized by the presence and growth of endometrial-like glands and stromas outside the uterine cavity. Endometriosis causes dysmenorrhea, dyspareunia, pelvic pain, and infertility in reproductive-age women. Dysmenorrhea is the most common symptom in patients with endometriosis. Ovulation inhibition is known to relieve dysmenorrhea, and oral contraceptive pills (OCPs) that contain syntheticestrogen and progestin can be used for this purpose (1). Oral contraceptive pills suppress ovulation and reduce the growth of endometrial tissue, thus reducing both menstrual flow and prostaglandins production (2). Recently, OCPs were also shown to down-regulate cell
Received May 16, 2007; revised and accepted August 21, 2007. All authors have received consulting fee from Nobelpharma Co., Ltd.Tokyo, Japan. Reprint requests to: Tasuku Harada, M.D., Department of Obstetrics and Gynecology, Tottori University School of Medicine, Yonago 683-8504, Japan (FAX: 81 859 38 6649; E-mail: tasuku@grape.med.tottori-u.ac.jp).

proliferation and increase apoptosis in the eutopic endometrium of women with endometriosis (3). Oral contraceptive pills, which have been used empirically to alleviatedysmenorrhea for many years, are generally well tolerated, with fewer metabolic and hormonal side effects than danazol or gonadotropin-releasing hormone agonist (GnRHa). Open clinical trials have shown that OCPs relieve dysmenorrhea. The Cochrane Database describes a few randomized clinical trials conducted from 1960 to 1970. Proctor et al. (4) revealed that OCPs with medium-dose estrogen and first- and...