Medicine 4: Progestin

Medicine 4: Progestin

What is it?

Progestins, synthetic compounds emulating the action of progesterone, serve a pivotal role in various medical applications, spanning from contraception to postmenopausal hormone replacement therapy. These medications interact with progesterone receptors, exhibiting distinct effects based on their generational classification or structural composition.¹

How does it work?

In women with primary dysmenorrhea, OCPs thin the endometrium, thereby reducing the amount of bleeding and inhibiting the metabolism of arachidonic acid to prostaglandin, effectively relieving cramping and pain.²

What is the efficacy?

Method: A phase II, randomized, double-blind, multicenter, placebo-controlled study. A total of 235 patients with primary dysmenorrhea. Patients were randomized to receive orally a placebo, DNG (0.5 mg/d, 1 mg/d, or 2 mg/d) or ethinylestradiol 0.02 mg/drospirenone 3 mg (an open-label reference drug) for 12 weeks.

Results: All DNG arms were superior to the placebo arm in terms of the change from baseline in the dysmenorrhea score. The results suggest an equal or greater effect of DNG 1 and 2 mg/d in relieving pain, when compared to the reference drug. In the safety profile of DNG, including irregular uterine bleeding, there was no obvious difference among the doses of DNG. A significant decrease in the serum estradiol concentration compared to that in the placebo arm was not observed in the DNG 1 mg/d arm but was observed in the DNG 2 mg/d arm.

Conclusion: The results suggest that DNG at a dose of 1 mg/d is an effective and well-tolerated treatment for primary dysmenorrhea.³

Side-effects:

Short-term effects: Unscheduled bleeding and changes in menses

Long-term effects: Hirsutism, and an increased prevalence of follicular ovarian cysts.¹

References

1. Edwards M, Can AS. Progestins. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan [cited 2025 May 16]. Available from: https://www.ncbi.nlm.nih.gov/books/NBK563211/

2. Casper RF. Progestin-only pills may be a better first-line treatment for endometriosis than combined estrogen-progestin contraceptive pills. Fertility and sterility. 2017 Mar 1;107(3):533-6.

1. Lessey BA, Young SL. Evaluation of the efficacy, safety, and clinically recommended dose of dienogest in the treatment of primary dysmenorrhea: a randomized, double-blind, multicenter, placebo-controlled study. Fertil Steril. 2019 Dec;112(6):1093-1101. doi: 10.1016/j.fertnstert.2019.08.013.