Barbara Boughton

May 21, 2012

May 21, 2012 (San Diego, California) — A postmarket study with 395 women shows that combined contraceptives with a shortened pill-free interval of 2 days reduces the severity of hormone withdrawal symptoms of headache and pelvic pain, according to researchers here at the American Congress of Obstetricians and Gynecologists (ACOG) 60th Annual Clinical Meeting.

In the double-blind, randomized study, which was conducted at 59 centers in the United States and Canada, women aged 18 to 50 years who had previously experienced headache or pelvic pain with birth control pills were switched and randomly assigned to receive either estradiol valerate plus dienogest (Qlaira or Natazia, Bayer), which has 2 hormone-free days per cycle, or norgestimate/ethinyl estradiol (Ortho Tri-Cyclen Lo, Janssen Pharmaceuticals), which is a 21/7-day contraceptive. About 250 women completed the study, which lasted for 13 cycles.

Results of the study indicated that those on contraceptives with a 2-day pill-free period experienced less severe pelvic pain and headache, were more likely to report that their hormone withdrawal symptoms were "much improved," and also used less rescue pain medication.

"A lot of patients get headaches and pelvic pain from birth control pills, and this medication [Qlaira] could be a good choice for women under 35 that experience these symptoms," said R. Garn Mabey Jr, MD, chief investigator for the study, who is also a gynecologist in private practice in Las Vegas, Nevada.

During the study, women were asked to fill out a diary showing their pill intake and symptoms. They were asked to rate the severity of their pelvic pain and headache on a 100-mm visual analog scale (VAS) at baseline and during cycles 3, 6, and 13. They were also asked to rate the severity of their symptoms of headache, bloating, breast tenderness, nausea, and vomiting on a 4-point scale with 1 being "no pain" and 4 being "severe pain" at baseline and after cycles 3, 6, and 13.

Patients also completed the Clinical Global Impression of Improvement Scale to rate their overall clinical experience with their contraceptive at cycles 3, 6, and 13.

The investigators found that when their pain was rated according to the VAS scale, women taking the contraceptive with 2 pill-free days per cycle recorded a 43.1-mm reduction in pain vs a 35-mm reduction in pain for women taking the contraceptive with 7 pill-free days per cycle (P < .05).

Fifty-six percent of women taking the contraceptive with the 2-day pill-free period had at least a 50% reduction in pain according to the VAS scale, with no increase in ibuprofen intake, compared with 42.2% in the group that took contraceptives with a 7-day pill-free period, the investigators said. Those who took pills with 2 hormone-free days also had a greater mean reduction in use of rescue pain medication from baseline to cycle 6 taken in days 21 to 28 of each cycle (number of 200-mg ibuprofen pills: 5.8 vs 4.6; 95% confidence interval [CI], -3 to +6).

Besides headache and pelvic pain, the investigators also assessed adverse events that affected more than 10% of participants (n = 191). Other than headache and pelvic pain, most other symptoms occurred at a similar rate in the 2 groups. Yet the group taking the 2-day hormone-free pills experienced more instances of vomiting (9.9 vs 4.4%) and urinary tract infections (12% vs 4.9%).

"A lot of data now suggest that there are estrogen withdrawal symptoms that occur in the hormone-free week in women taking pills with a pill-free week each cycle," commented Susan Richman, MD, MPH, associate clinical professor in the Department of Obstetrics and Gynecology at the Yale School of Medicine in New Haven, Connecticut.

"But this kind of study is also another way for companies to get the name of their pill out there. They're not doing anything radically different. All birth control pills do the same things — they stop you from ovulating and thicken your cervical mucus so you won't get pregnant. There are really only very small differences between pills these days in the types of estrogen and progesterone they use," she added.

Dr. Mabey has received payments from Affiliated Clinical Research for his participation in the study. Dr. Richman has disclosed no relevant financial relationships.

American Congress of Obstetricians and Gynecologists (ACOG) 60th Annual Clinical Meeting. Abstract #8. Presented May 7, 2012.


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