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Med Rx.

Desogestrel + Ulipristal Acetate [For uterine fibroids]

Moderate 6 published sources

This interaction is documented in this data source.

Desogestrel
Checked as Desogestrel
Ulipristal Acetate [For uterine fibroids]
Checked as Ulipristal

2 documented mechanisms

This source documents more than one distinct mechanism for this pair. Each is shown with its own effect, advice and sources rather than merged into one.

  1. Mechanism 1: Antagonism

    Moderate

    via Desogestrel and Ulipristal

    What happens

    RECOMMENDED: Coadministration of ulipristal with combination hormonal contraceptives may reduce the efficacy of both treatments for the prevention of pregnancy. Ulipristal and the progestin component of hormonal contraceptives both bind to the progesterone receptor. Theoretically, competitive inhibition of the receptor may occur, which may diminish the effects of each on ovulation.

    What to do

    Concomitant use of ulipristal with combination hormonal contraceptives should be avoided. After emergency contraception with ulipristal, routine contraception should be continued or initiated as soon as possible to ensure ongoing prevention of pregnancy. Patients who wish to use progestogen-containing contraceptives should do so no sooner than 5 days after taking ulipristal, and they should use a reliable barrier method of contraception until their next menstrual period.

    4 sources

    1. "Product Information. ella (ulipristal)." Afaxys Inc., Charleston, SC.
    2. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
    3. Schubert W, Eriksson U, Edgar B, Cullberg G, Hedner T "Flavonoids in grapefruit juice inhibit the in vitro hepatic metabolism of 17B-estradiol." Eur J Drug Metab Pharmacokinet 20 (1995): 219-24
    4. Weber A, Jager R, Borner A, et al. "Can grapefruit juice influence ethinyl estradiol bioavailability?" Contraception 53 (1996): 41-7

  2. Mechanism 2: Antagonism

    Moderate

    via Desogestrel and Ulipristal

    What happens

    Coadministration of ulipristal with combination hormonal contraceptives may reduce the efficacy of both treatments for the prevention of pregnancy. Ulipristal and the progestin component of hormonal contraceptives both bind to the progesterone receptor. Theoretically, competitive inhibition of the receptor may occur, which may diminish the effects of each on ovulation.

    What to do

    Concomitant use of ulipristal with combination hormonal contraceptives should be avoided. After emergency contraception with ulipristal, routine contraception should be continued or initiated as soon as possible to ensure ongoing prevention of pregnancy. Patients who wish to use progestogen-containing contraceptives should do so no sooner than 5 days after taking ulipristal, and they should use a reliable barrier method of contraception until their next menstrual period.

    2 sources

    1. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0
    2. "Product Information. Ella (ulipristal)." Afaxys Inc. (2022):

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