A prospective, randomized, pharmacodynamic study of quick-starting a desogestrel progestin-only pill following ulipristal acetate for emergency contraception.

STUDY QUESTION: Is there a pharmacodynamic interaction between ulipristal acetate (UPA) 30 mg for emergency contraception and a daily progestin-only contraceptive pill, desogestrel (DSG) 0.75 mg, when initiated the next day? SUMMARY ANSWER: In this study, DSG impaired the ability of UPA to delay ovulation, but UPA had little impact on the onset of contraceptive effects due to DSG. WHAT IS KNOWN ALREADY: UPA is a progesterone receptor modulator used for emergency contraceptive (EC) at the dose of 30 mg. UPA delays ovulation by at least 5 days when administered in the mid to late follicular phase. In theory, potent progestins could reactivate progesterone signaling that leads to follicle rupture, thereby impacting the effectiveness of UPA as EC. In addition, UPA could alter the onset of the contraceptive effect of progestin-containing contraceptives started immediately after UPA. STUDY DESIGN, SIZE, DURATION: A single-blind (for observer), placebo-controlled, partial crossover study was conducted in two sites [Dominican Republic (DR) and the Netherlands (NDL)] over 11 months from October 2012 to September 2013. Healthy female volunteers participated in two of the three treatment cycles separated by a washout cycle. Treatment combinations studied were as follows: (i) a single 30 mg dose of UPA followed by 75 µg per day DSG for 20 days, (ii) a single 30 mg dose of UPA followed by 20 days of placebo matching that of DSG (PLB2) or (iii) one tablet of placebo-matching UPA (PLB1) followed by 75 µg per day DSG for 20 days. Participants were randomized to one of the three treatment sequences (UPA + DSG/UPA + PLB2, PLB1 + DSG/UPA + DSG and UPA + PLB2/PLB1 + DSG) when a lead follicle was ≥ 14 to <16 mm diameter on transvaginal ultrasound imaging (TVU). PARTICIPANTS/MATERIAL, SETTING, METHODS: A total of 71 women were included, and 49 were randomized to a first treatment combination of the three period sequences (20 in the DR and 29 in the NDL); 41 of the 49 continued and completed two treatment combinations (20 in the DR and 21 in the NDL). MAIN RESULTS AND THE ROLE OF CHANCE: Initiating DSG treatment the day after UPA significantly reduced the ovulation delaying effect of UPA (P = 0.0054). While ovulation occurred in only one of the 29 UPA-only cycles (3%) in the first 5 days, it occurred in 13 of the 29 (45%) UPA + DSG cycles. LIMITATIONS, REASONS FOR CAUTION: This was a small, descriptive, pharmacodynamic study in which some findings differed by study site. Distinguishing between a cystic corpus luteum and a luteinized unruptured follicle (LUF) by TVU was difficult in some cases; however, the investigators reached consensus, when the study was still blinded, regarding ovulation based on hormone levels and careful review of daily TVU images. WIDER IMPLICATIONS OF THE FINDINGS: Initiating the use of a DSG progestin-only pill (POP) immediately after UPA reduces the ability of UPA to delay ovulation and thus may decrease its efficacy as EC. If starting a DSG POP after using UPA for EC, and possibly any progestin-only method, consideration should be given to delaying for at least 5 days after UPA intake in order to preserve the ovulation delaying effects of UPA.

The combined contraceptive vaginal ring and bone mineral density in healthy pre-menopausal women.

BACKGROUND: Hormonal contraceptives have been associated with various effects on the bone mineral density (BMD) of pre-menopausal women. The aim of this study was to assess the effects of a vaginal contraceptive ring on BMD in pre-menopausal women and compare them with those of non-hormonal contraceptive use. METHODS: This open-label, multicentre study used dual-energy X-ray absorptiometry to measure BMD in the lumbar spine (L(2)-L(4)) and femoral neck regions. Subjects were assigned 3:1 to receive a contraceptive ring (n = 105) or a non-hormonal contraceptive control (n = 39) and were assessed after 13 and 26 cycles of contraceptive ring treatment or 12 and 24 months of control treatment. RESULTS: No change from baseline in BMD (Z-scores) was seen in contraceptive ring users (n = 73) at either time-point. In the control group (n = 30), BMD increased slightly from baseline resulting in significant differences (P < 0.0001) between the two groups at cycle 26/month 24. These differences are not clinically relevant, although some degree of acquisition of peak bone mass might have been prevented in the contraceptive ring group. The contraceptive ring was generally well tolerated; a higher incidence of treatment-related adverse events was observed in the contraceptive ring group compared with the non-hormonal contraceptive control group. CONCLUSIONS: In healthy pre-menopausal women, 2 years of contraceptive ring use produced no changes in BMD.