- Ulipristal acetate (ellaOne)
- is a selective progesterone-receptor modulator that seems to be as effective as levonorgestrel for prevention of pregnancy. Ulipristal acetate may be used up to 120h after unprotected sexual intercourse or contraceptive failure
- it is orally active and taken as a single dose
Mechanism of Action
- ulipristal acetate (also known as CDB-2914 and VA2914) is a synthetic steroid derived from 19-norprogesterone
- is a selective progesterone receptor modulator (SPRM), a class of compounds that exert tissue-selective full agonist, antagonist or partial agonist effects at the progesterone receptor
- ulipristal has been described as a second-generation SPRM. In vivo, ulipristal has much weaker antiglucocorticoid activity than mifepristone as a result of differences in their active metabolites
- primary mechanism of action is thought to be inhibition or delay of ovulation. A single midfollicular dose has been shown to suppress growth of lead follicles
- administration just before, or in some cases just after, the luteinising hormone surge can inhibit follicular rupture
- endometrial changes may also play a role. Early luteal administration of ulipristal results in delayed endometrial maturation and alterations in progesterone-dependent markers of implantation
- a mid-luteal dose has been shown to induce early endometrial bleeding in a dose-dependent manner
- postulated that alterations to the endometrium may inhibit implantation by rendering the uterus less receptive to the trophoblast. However, it is not known if ulipristal has a direct endometrial effect or if the observed changes are a result of an ovarian effect
Dose and frequency of administration (4)
- One tablet (30mg) as a single dose taken as soon as possible up to 120 hours after UPSI.
Duration of Treatment (4)
- A single dose is permitted
- If vomiting occurs within 3 hours of ulipristal being taken a repeat dose can be supplied
- Repeated doses can be given within the same cycle. Please note:
- If within 7 days of previous levonorgestrel offer levonorgestrel again (not ulipristal)
- If within 5 days of ulipristal then offer ulipristal again (not levonorgestrel)
Criteria for exclusion (4)
- Informed consent not given.
- Individuals under 16 years old and assessed as lacking capacity to consent using the Fraser Guidelines.
- Individuals 16 years of age and over and assessed as lacking capacity to consent.
- This episode of UPSI occurred more than 120 hours ago. N.B. A dose may be given if there have been previous untreated or treated episodes of UPSI within the current cycle if the most recent episode of UPSI is within 120 hours.
- Known or suspected pregnancy (N.B. a previous episode of UPSI in this cycle is not an exclusion. Consider pregnancy test if more than three weeks after UPSI and no normal menstrual period).
- Less than 21 days after childbirth.
- Less than 5 days after miscarriage, abortion, ectopic pregnancy or uterine evacuation for gestational trophoblastic disease (GTD).
- Known hypersensitivity to the active ingredient or to any component of the product - see Summary of Product Characteristics
- Use of levonorgestrel or any other progestogen in the previous 7 days (i.e. hormonal contraception, hormone replacement therapy or use for other gynaecological indications).
- Concurrent use of antacids, proton-pump inhibitors or H2-receptor antagonists.
- Severe asthma controlled by oral glucocorticoids.
- Individuals using enzyme-inducing drugs/herbal products or within 4 weeks of stopping.
- Acute porphyria
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Cautions including any actions to be taken (4):
- All individuals should be informed that insertion of a copper intrauterine device (Cu-IUD) within five days of UPSI or within five days from earliest estimated ovulation is the most effective method of emergency contraception. If a Cu-IUD is appropriate and acceptable supply oral EC and refer to the appropriate health service provider
- Ulipristal is ineffective if taken after ovulation
- If individual vomits within three hours from ingestion, arepeat dose may be given
- Body Mass Index (BMI) >26kg/m2 or weight >70kg - individuals should be advised that though oral EC methods may be safely used, a high BMI may reduce the effectiveness. A Cu-IUD should be recommended as the most effective method of EC
- Consideration should be given to the current disease status of those with severe malabsorption syndromes, such as acute/active inflammatory bowel disease or Crohn's disease. Although the use of ulipristal is not contra-indicated it may be less effective and so these individuals should be advised that insertion of Cu-IUD would be the most effective emergency contraception for them and referred accordingly if agreed
- Breast feeding - advise to express and discard breast milk for 7 days after ulipristal dose
. - The effectiveness of ulipristal can be reduced by progestogen taken in the following 5 days and individuals must be advised not to take progestogen containing drugs for 5 days after ulipristal
- If the individual is less than 16 years of age an assessment based on Fraser guidelines must be made and documented
- If the individual is less than 13 years of age the healthcare professional should speak to local safeguarding lead and follow the local safeguarding policy
- If the individual has not yet reached menarche consider onward referral for further assessment or investigation
Side effects or safety issues:
- most commonly reported side effects are abdominal pain and menstrual disorders (irregular vaginal bleeding, premenstrual syndrome, uterine cramps)
- study data have shown that the post-treatment cycle length is on average 2.9 days longer than the expected length
- some 7% of women reported a shortened cycle, and 19.2% reported an increase in cycle length of more than 7 days
- have been no associated adverse outcomes in the small numbers of inadvertent pregnancies that have occurred to date. The manufacturer has put a variety of measures in place to monitor outcomes of exposure during pregnancy
Drug interactions:
- Ulipristal is metabolised via cytochrome P450, in particular CYP3A4 Liver enzyme inducers Liver enzyme inhibitors Drugs that increase gastric pH Other contraceptives
- CYP3A4 inducers (e.g. rifampicin, phenytoin, carbamazepine, ritonavir, St John's wort) may reduce plasma concentrations of ulipristal and may reduce efficacy - see linked item below for further information
- The effect of CYP3A4 inhibitors (e.g. ketoconazole, itraconazole, clarithromycin) may increase exposure to ulipristal, but the significance is uncertain
- Use of ulipristal with antacids, proton pump inhibitors and H2 receptor antagonists, or any other drugs that increase gastric pH, may reduce absorption of ulipristal and decrease efficacy
- Ulipristal binds to progesterone receptors and so may reduce the efficacy of progestogen-containing contraceptives.
Reference:
- 1)Creinin MD et al. Progesterone receptor modulator for emergency contraception: a randomized controlled trial. Obstet Gynecol 2008;108:1089-1097
- 2) Fine P et al. Ulipristal acetate taken 48-120 hours after intercourse for emergency contraception. Obstet Gynecol. 2010 Feb;115(2 Pt 1):257-63.
- 3) FSRH (October 2009). Ulipristal Acetate (ellaOne®) - product review
- 4) Patient Group Direction (PGD) (NHS Specialist Pharmacy Service). Supply and/or administration of ulipristal acetate 30mg tablet for emergency contraception (Accessed 17th March 2021).