Treatment of Unscheduled Bleeding in Continuous Oral... : Obstetrics & Gynecology (original) (raw)
Original Research
Treatment of Unscheduled Bleeding in Continuous Oral Contraceptive Users With Doxycycline
A Randomized Controlled Trial
Kaneshiro, Bliss MD, MPH; Edelman, Alison MD, MPH; Carlson, Nichole PhD; Morgan, Kristin; Nichols, Mark MD; Jensen, Jeffrey MD, MPH
From the Department of Obstetrics and Gynecology, University of Hawaii, Honolulu, Hawaii; the Departments of Obstetrics and Gynecology and Public Health and Preventive Medicine, Oregon Health & Science University, Portland, Oregon; and the Department of Biostatistics and Informatics, University of Colorado Denver, Colorado.
Supported by the unrestricted research grants from Family Planning Fellowship and Wyeth Pharmaceuticals.
Corresponding author: Bliss Kaneshiro, MD, MPH, Department of Obstetrics and Gynecology, 1319 Punahou Street #824, Honolulu, HI 96826; e-mail [email protected].
Financial Disclosure Dr. Edelman has been a consultant for Bayer Healthcare and Schering Plough. Dr. Jensen received a consulting fee or honorarium from Wyeth Pharmaceuticals for serving on the advisory board for Lybrel. He has also received compensation from Wyeth for serving as a speaker. He has served as a consultant to Bayer Healthcare and Schering Plough. He has received grants or has grants pending from Bayer Healthcare and Warner Chilcott. He has also received the following from Bayer Healthcare: Payment for development of educational presentations including service on speakers' bureaus and travel/accommodations expenses covered or reimbursed in conjunction with speaker activities as part of CME programs. The other authors did not report any potential conflicts of interest.
OBJECTIVE:
To estimate whether doxycycline, a matrix metalloproteinase inhibitor, would decrease unscheduled bleeding associated with initiation of a continuous oral contraceptive pill.
METHODS:
Participants initiating a continuous oral contraceptive pill (20 micrograms of ethinyl estradiol/90 micrograms of levonorgestrel) were randomly assigned to receive either doxycycline (100 mg orally twice daily) or placebo taken for 5 days at the onset of each bleeding or spotting episode during the first 84 days of the study period. For the final 28 days of the study, participants were observed on the oral contraceptive pill alone. The primary outcome was the number of bleeding and spotting days. A sample size of 66 (33 in each arm) was calculated to detect a 50% reduction in bleeding (β=0.80, α=0.05) and accounted for a 30% dropout rate.
RESULTS:
Sixty-six women were randomly assinged (33 in each study group). There were no significant differences during the 84-day treatment in bleeding or spotting days (doxycycline [mean {standard error}, placebo, _P_=.32) or the length of the longest bleeding or spotting episode (doxycycline, placebo, _P_=.70) between study groups. Similarly, no significant differences in bleeding patterns existed between groups during the final 28 days.
CONCLUSION:
Doxycycline, administered once bleeding has started, does not decrease unscheduled bleeding or shorten episodes of unscheduled bleeding in continuous oral contraceptive pill users.
CLINICAL TRIAL REGISTRATION:
ClinicalTrials.gov, www.clinicaltrials.gov, NCT00480532.
LEVEL OF EVIDENCE:
I
© 2010 by The American College of Obstetricians and Gynecologists. Published by Wolters Kluwer Health, Inc. All rights reserved.