Ulipristal acetate

Introduction:

Ulipristal acetate is a new oral emergency contraceptive. It can not only be used within 120 hours after unprotected sexual intercourse, but also the efficacy of emergency contraception will not decline with the delay of medication time. At the same time, it has good safety and tolerance. Compared with levonorgestrel, the most commonly used emergency contraceptive, ulinastatin acetate has wider clinical applicability and has the potential to prevent more accidental pregnancies.

CAS：126784-99-4

Molecular formula: C30H37NO4

Molecular weight: 475.62

Structural type:

Pharmacological action:

Ulipristal acetate is a progesterone agonist / antagonist, and its mechanism is to inhibit or delay ovulation; However, endometrial changes may also be one of the reasons for the efficacy.Ulipristal acetate is a selective progesterone receptor modulator, which has antagonistic and partial agonistic effects on progesterone receptor. It binds to the progesterone receptor in the human body, thereby preventing progesterone from binding to the progesterone receptor. The efficacy of ulipristal acetate depends on the time of administration in the menstrual cycle. Administration in the middle stage of follicular hyperplasia can inhibit follicular formation and reduce the concentration of estradiol. Administration at the peak of luteinizing hormone can delay the rupture of follicles for 5 ~ 9 days. Early administration of corpus luteum could not significantly delay endometrial maturation, but could reduce endometrial thickness by 0.6 ± 2.2mm (mean ± SD).