Ulipristal Acetate/Ulipristal is a selective progesterone receptor modulator with anti-progesterone activity. Ulipristal binds to the progesterone receptor (PR), thereby inhibiting PR-mediated gene expression, and interfering with progesterone activity in the reproductive system. As a result, this agent may suppress the growth of uterine leiomyomatosis. Furthermore, by inhibiting or delaying ovulation and effecting endometrial tissue, ulipristal can be used as emergency contraception.
Ulipristal Acetate is an orally bioavailable, acetate salt of ulipristal, a selective progesterone receptor modulator with anti-progesterone activity. Ulipristal binds to the progesterone receptor (PR), thereby inhibiting PR-mediated gene expression, and interfering with progesterone activity in the reproductive system. As a result, this agent may suppress the growth of uterine leiomyomatosis. Furthermore, by inhibiting or delaying ovulation and effecting endometrial tissue, ulipristal can be used as an emergency contraception
Ulipristal is a selective progesterone receptor modulator used for the purposes of emergency contraception (Ella) and for the treatment of uterine fibroids (Fibristal). It is a derivative of 19-norprogesterone and has both antagonistic and partial agonist activity at the progesterone receptor. It also binds to the glucocorticoid receptor, however, compared to mifepristone (a progesterone receptor antagonist), ulipristal is more tolerable and has lower glucocorticoid activity and better binding affinity. Ulipristal is currently recommended as first-line therapy for emergency contraception, due to improved efficacy and similar side effect profile as compared to the traditional use of levonorgestrel or the Yuzpe regimen. The exact mechanism of action for ulipristal is still currently debated, though there is evidence that it functions by inhibiting ovulation. A recent systematic review proclaimed that the majority of available evidence demonstrates an inhibitory effect on ovulation rather than a postfertilization effect on the endometrium, which has been heavily debated due to ethical concerns related to abortion. Nevertheless, current and ongoing research into the agent’s mechanism of action as an emergency contraceptive continues to provide potentially plausible evidence that ulipristal may, in fact, elicit activity on the endometrium that prevents embryo implantation.
Mechanism of Action of Ulipristal
The exact mechanism of action of ulipristal has been heavily debated. On one hand, the majority of official prescribing information labels, monographs, and prior research studies for ulipristal indicated as an emergency contraceptive suggest that its primary mechanism of the action revolves around inhibiting or delaying ovulation by suppressing surges in LH that result in the postponement of follicular rupture. Conversely, some of the latest investigations pertaining to ulipristal’s mechanism of action as an emergency contraceptive propose that it principally elicits its action by preventing embryo implantation, as opposed to preventing ovulation. Although previous investigations have shown that ulipristal essentially has the ability to prevent ovulation equivalent to placebo (ie. null effect or ability) when administered during LH peaks one to two days before ovulation, the agent still demonstrates a stable and consistently high contraceptive effect of approximately >=80% when used at this time. Subsequently, current studies attempt to investigate how ulipristal could elicit emergency contraception via ovulation prevention under circumstances where ovulation had already clearly been observed. Endometrial biopsy samples studied from such circumstances in such investigations subsequently show that the administered ulipristal causes endometrial tissue to become inhospitable and unsuitable for embryo implantation where a variety of genes characteristic of receptive, pro-gestational endometrium are downregulated. Nevertheless, most if not all proposed mechanisms commonly agree that ulipristal ultimately demonstrates its pharmacological effects by binding to human progesterone receptors and prevents natural, endogenous progesterone from occupying such receptors. Regardless, however, considering current and on-going research into ulipristal’s ability to prevent embryo implantation, the notion that the medication can elicit post-fertilization effects potentially raises alerts and or ethical debates over the use of ulipristal owing to the potential abortifacient activity which is considered to be on par or equipotent to that of mifepristone. Attention should be drawn to the fact that some prescribing information, however, such as the US FDA label for ulipristal indicated for emergency contraception, has included new supplementary commentary since 2018 that directly warns about ulipristal not being indicated for termination of existing pregnancies and suggesting that ulipristal use may confer alterations to the endometrium that may affect implantation and contribute to efficacy. In the treatment of fibroids, ulipristal has been shown to exert direct actions on fibroids reducing their size through inhibition of cell proliferation and induction of apoptosis.
Ulipristal Indications
- As the product Ella (available in Canada and the US), ulipristal is indicated for use as emergency contraception after unprotected intercourse or possible contraceptive failure when administered within 120 hours (5 days) after unprotected intercourse or a known or suspected contraceptive failure. As the product Fibristal (available in Canada), ulipristal is indicated for the treatment of the signs and symptoms of uterine fibroids in adult women.
- Ulipristal acetate is indicated for one treatment course of pre-operative treatment of moderate to severe symptoms of uterine fibroids in adult women of reproductive age. Ulipristal acetate is indicated for intermittent treatment of moderate to severe symptoms of uterine fibroids in adult women of reproductive age who are not eligible for surgery.
- Emergency contraception within 120 hours (five days) of unprotected sexual intercourse or contraceptive failure.
- Ulipristal acetate is indicated for the pre-operative treatment of moderate to severe symptoms of uterine fibroids in adult women of reproductive age. Ulipristal acetate is indicated for intermittent treatment of moderate to severe symptoms of uterine fibroids in adult women of reproductive age.
- Emergency contraception within 120 hours (5 days) of unprotected sexual intercourse or contraceptive failure.
- Leiomyoma of uterus
- Moderate Uterine Fibroids
- Severe Uterine Fibroids
- Birth Control
- Prevention of pregnancy following unprotected intercourse or a known or suspected contraceptive failure
Contraindications of Ulipristal
- are allergic to ulipristal or any ingredients of the medication
- are, or maybe pregnant
- chronic heart failure
- kidney disease with a reduction in kidney function
- are bald due to non-hereditary factors (e.g., caused by illnesses such as iron deficiency, thyroid disorders, or medications such as cancer chemotherapy)
- are or may be pregnant or are nursing
- have shaved, broken, inflamed, irritated, infected, or severely sunburned skin on the scalp
- have untreated high blood pressure
- have recently discontinued certain medications such as birth control or cancer chemotherapy
- have certain grooming habits (e.g., cornrowing, tight ponytails)
Dosage of Ulipristal
Strengths: 30 mg
Contraception
- 30 mg orally as soon as possible within 120 hours (5 days) after unprotected intercourse or a known or suspected contraceptive failure
Ulipristal Side Effects
More common
- Abdominal or stomach pain
- headache
- nausea
- Fast or irregular heartbeat
- weight gain (rapid) of more than 5 pounds (2 pounds in children)
- backache
- changes in hair colour or texture
- cold- or flu-like symptoms (e.g., runny or stuffy nose, cough, sore throat)
- continuous itching or skin rash
- dental problems
- eye irritation
- irritation, redness, dryness in the area where medication was applied
- muscle strain or spasm
Common
- Chest pain
- shortness of breath
- acne where medication was applied
- burning of the scalp
- changes in blood pressure
- dizziness
- feeling faint
- headache
- infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।" data-rx-term="inflammation" data-rx-definition="Inflammation is the body’s response to injury, infection, or irritation, often causing pain, swelling, heat, or redness. সহজ বাংলা: শরীরের প্রদাহ; ব্যথা, ফোলা বা লালভাব হতে পারে।">inflammation or soreness at the hair root
- persistent local rash
- rapid heartbeat
Rare
- Bloating
- flushing or redness of skin
- swelling of feet or lower legs
- Numbness or tingling of hands, feet, or face
- Skin rash and itching
- rapid weight gain
- sudden weight gain
- swelling of the hands or feet
- temporary hair loss
- unwanted facial hair growth
Drug Interactions of Ulipristal 30 mg Tablet
may interact with following drugs, supplements, & may change the efficacy of drugs
- abiraterone acetate
- “azole” antifungals (e.g., itraconazole, ketoconazole, voriconazole)
- barbiturates (e.g., butalbital, pentobarbital, phenobarbital)
- calcium channel blockers (e.g., amlodipine, diltiazem, nifedipine, verapamil)
- carbamazepine
- conivaptan
- cyclosporine
- dexamethasone
- grapefruit juice
- haloperidol
- HIV non-nucleoside reverse transcriptase inhibitors (NNRTIs; e.g., delavirdine, efavirenz, etravirine, nevirapine)
- HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir, saquinavir)
- imatinib
- lomitapide
- macrolide antibiotics (e.g., clarithromycin, erythromycin)
- mifepristone
- metronidazole
- modafinil
- nefazodone
- norfloxacin
- oxcarbazepine
- phenytoin
- progestins (e.g., dienogest, levonorgestrel, medroxyprogesterone, norethindrone)
- St. John’s wort
- sertraline
- tetracycline
- tocilizumab
- topiramate
If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to
- stop taking one of the medications,
- change one of the medications to another,
- change how you are taking one or both of the medications, or
- leave everything as is.
Pregnancy Category of Ulipristal 30 mg Tablet
FDA Pregnancy Category – X
Pregnancy
This medication will not interrupt a pregnancy that is already established. It is not intended for use during pregnancy.
Breast-feeding
Ulipristal is a selective progesterone receptor modulator used in a single dose as an emergency postcoital contraceptive. No information is available on the clinical use of ulipristal during breastfeeding. The manufacturer recommends avoiding the use of ulipristal acetate during breastfeeding; others recommend withholding breastfeeding for 24 hours after use, based on the low levels in breastmilk. This medication is not intended to be used by girls who have not yet had their first menstrual period. The safety and effectiveness of using this medication for women less than 18 years of age have not been established.
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