A new combination of drugs has emerged as a “promising candidate” for an on-demand contraceptive pill, suggests preliminary research published online in the journal BMJ Sexual & Reproductive Health.
The combination of ulipristal acetate, currently used as an emergency contraceptive medication, plus the COX-2 inhibitor meloxicam, a type of nonsteroidal anti-inflammatory drug, appears to be highly effective in disrupting ovulation at the point in the cycle when the risk of pregnancy is the greatest, known as peak fertility.
The days just before ovulation, known as the luteal surge, are when it is most difficult to disrupt ovulation and when fertilization of the egg is most likely to occur.
Ulipristal acetate disrupts ovulation, but only if taken before the luteal surge begins. Drugs like COX-2 inhibitors, on the other hand, can still disrupt ovulation even after the luteal surge has started.
So the researchers wanted to find out if the combination of both drugs might work at peak fertility, with the goal of identifying a prime candidate for a potentially highly effective on-demand contraceptive pill for use before or after sex as needed, or as an emergency. Contraceptive pill.
Ten healthy women between the ages of 18 and 35 were included in the study, all of whom had regular periods.
Each woman was monitored through two menstrual cycles: a baseline cycle, to identify normal ovulatory patterns, and a treatment cycle, when participants were given a combined dose of ulipristal acetate 30 mg and meloxicam 30 mg around the time of the luteal surge.
Ultrasound scans and key hormones were measured to identify the luteal surge and whether ovulation had occurred or was disrupted. Nine women completed both baseline and treatment cycles and were included in the final analysis.
Ovulation was disrupted in 6 women in the treatment cycle. Most (89%, 8) met certain criteria for incomplete ovulation. Treatment cycles were about 3 days longer: this cycle length disruption is particularly important for those who may also be using fertility awareness methods, the researchers explain.
This is exploratory research, involving only 9 women, so further studies on safety and efficacy in larger numbers of women are needed, they emphasize.
But the results are promising, they suggest, because they show that the combination of ulipristal acetate plus meloxicam can disrupt ovulation when conception risk is highest, making it a “promising candidate for evaluation as a pericoital oral contraceptive.”
They add: “When we compare ovulation disruption rates in our study with the previous studies on which our protocol is based, the combination of [ulipristal acetate] and meloxicam disrupted ovulation at every phase of the fertile window more than any other medication previously studied.”
The findings also suggest that adding meloxicam to ulipristal acetate may increase the latter’s effectiveness as emergency contraception, they say.
BMJ Sexual & Reproductive Health
Method of research
Topic of Research
Potential candidate for oral pericoital contraception: evaluating ulipristal acetate plus cyclooxygenase-2 inhibitor for ovulation disruption
Article Publication Date
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