Low-dose oral contraceptive pill for dysmenorrhea associated with endometriosis: a placebo-controlled, double-blind, randomized trial.
OBJECTIVE
To evaluate the efficacy of a low-dose oral contraceptive pill (OCP) for patients with dysmenorrhea associated with endometriosis.


METHODS
A double-blind, randomized, placebo-controlled trial.


METHODS
Clinical trial sites in Japan.


METHODS
One hundred patients with dysmenorrhea associated with endometriosis. Most enrolled patients had radiologic evidence of endometriosis rather than surgical diagnosis.


METHODS
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.


METHODS
After four cyclic treatments, 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.


RESULTS
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.


CONCLUSIONS
The present study clearly demonstrated for the first time that OCPs could be used to effectively and safely treat pain associated with endometriosis.
Harada
Tasuku
T
Department of Obstetrics and Gynecology, Tottori University School of Medicine, Yonago, Japan. tasuku@grape.med.tottori-u.ac.jp
Momoeda
Mikio
M
Taketani
Yuji
Y
Hoshiai
Hiroshi
H
Terakawa
Naoki
N
D000328:Adult; D000700:Analgesics / Q000627:therapeutic use; D003276:Contraceptives, Oral / Q000009:adverse effects / Q000627:therapeutic use*; D003277:Contraceptives, Oral, Combined / Q000009:adverse effects / Q000627:therapeutic use*; D003280:Contraceptives, Oral, Synthetic / Q000009:adverse effects / Q000627:therapeutic use*; D004311:Double-Blind Method; D004412:Dysmenorrhea / Q000188:drug therapy* / Q000209:etiology / Q000473:pathology; D004715:Endometriosis / Q000150:complications / Q000188:drug therapy* / Q000473:pathology; D004997:Ethinyl Estradiol / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D007564:Japan; D009640:Norethindrone / Q000009:adverse effects / Q000627:therapeutic use*; D010147:Pain Measurement; D017699:Pelvic Pain / Q000209:etiology / Q000517:prevention & control; D011788:Quality of Life; D013997:Time Factors; D016896:Treatment Outcome
D000700:Analgesics; D003276:Contraceptives, Oral; D003277:Contraceptives, Oral, Combined; D003280:Contraceptives, Oral, Synthetic; D004997:Ethinyl Estradiol; D009640:Norethindrone