Formulary
Mifepristone: Indications, Dosing, Side Effects and Interactions
Mifepristone, an antiprogestogenic steroid, sensitises the myometrium to prostaglandin-induced contractions and ripens the cervix.
MedNext Academy | 4 min read
Mifepristone: Indications, Dosing, Side Effects and Interactions
Mifepristone, an antiprogestogenic steroid, sensitises the myometrium to prostaglandin-induced contractions and ripens the cervix.
Drug action
Mifepristone, an antiprogestogenic steroid, sensitises the myometrium to prostaglandin-induced contractions and ripens the cervix.
Indications and dose
**Cervical ripening before mechanical cervical dilatation**
- **Adult** (By Mouth): for termination of pregnancy of up to 84 days gestation (under close medical supervision) 200 mg for 1 dose, to be taken 36-48 hours before procedure.
**Induction of labour in intra-uterine fetal death in women without uterine scarring (under close medical supervision)**
- **Adult** (By Mouth): 200 mg for 1 dose, dose followed by dinoprostone or misoprostol, given in accordance with national protocols.
**Medical termination of intra-uterine pregnancy of up to 49 days gestation (under close medical supervision)**
- **Adult** (By Mouth): 600 mg for 1 dose, dose followed 36-48 hours later (unless abortion already complete) by gemeprost 1 mg by vagina or misoprostol 400 micrograms by mouth, alternatively 200 mg for 1 dose, dose followed 36-48 hours later (unless abortion already complete) by gemeprost 1 mg by vagina; observe for at least 3 hours (or until bleeding or pain at acceptable level); follow-up visit within 2 weeks to verify complete expulsion and to assess vaginal bleeding.
**Medical termination of intra-uterine pregnancy of 50-63 days gestation (under close medical supervision)**
- **Adult** (By Mouth): 600 mg for 1 dose, alternatively 200 mg for 1 dose, dose followed 36-48 hours later (unless abortion already complete) by gemeprost 1 mg by vagina; observe for at least 3 hours (or until bleeding or pain at acceptable level); follow-up visit within 2 weeks to verify complete expulsion and to assess vaginal bleeding.
**Termination of pregnancy of 13-24 weeks gestation (in combination with a prostaglandin) (under close medical supervision)**
- **Adult** (By Mouth): 600 mg for 1 dose, alternatively 200 mg for 1 dose, dose followed 36-48 hours later by gemeprost 1 mg by vagina every 3 hours up to max. 5 mg or misoprostol; if abortion does not occur, 24 hours after start of treatment repeat course of gemeprost 1 mg by vagina up to max. 5 mg; follow-up visit after appropriate interval to assess vaginal bleeding recommended.
**Missed miscarriage**
- **Adult** (By Mouth): 200 mg for 1 dose, dose followed 48 hours later (unless expulsion of gestational sac already complete) by misoprostol 800 micrograms by vagina, by mouth, or by sublingual administration.
Cautions
Adrenal suppression (may require corticosteroid); anticoagulant therapy; asthma (avoid if severe and uncontrolled); existing cardiovascular disease; haemorrhagic disorders; history of endocarditis; prosthetic heart valve; risk factors for cardiovascular disease
Contraindications
Acute porphyrias ; chronic adrenal failure; suspected ectopic pregnancy (use other specific means of termination); uncontrolled severe asthma
Side effects
Common or very common Abdominal cramps; diarrhoea; infection; nausea; pelvic inflammatory disease; uterine disorders; vaginal haemorrhage (sometimes severe); vomiting Uncommon Hypotension Rare or very rare Angioedema; chills; dizziness; erythema nodosum; fever; headache; hot flush; malaise; skin reactions; toxic epidermal necrolysis; toxic shock syndrome; uterine rupture
Interactions
**Other interactions (7):**
- On the basis of mifepristone's metabolism by CYP3A4, it is possible that ketoconazole, itraconazole, erythromycin, and grapefruit juice may inhibit its metabolism (increasing serum levels of...
- Furthermore, rifampicin, dexamethasone, St.
- John's Wort and certain anticonvulsants (phenytoin, phenobarbital, carbamazepine) may induce mifepristone metabolism (lowering serum levels of mifepristone).
- Based on in vitro inhibition information, co-administration of mifepristone may lead to an increase in serum levels of drugs that are CYP3A4 substrates.
- Due to the slow elimination of mifepristone from the body, such interaction may be observed for a prolonged period after its administration.
- Therefore, caution should be exercised when mifepristone is administered with drugs that are CYP3A4 substrates and have narrow therapeutic range, such as cyclosporine, tacrolimus, sirolimus,...
Pregnancy
Cervical ripening before mechanical cervical dilatation for termination of pregnancy of up to 84 days gestation (under close medical supervision) for mifepristone By mouth Adult 200 mg for 1 dose, to be taken 36-48 hours before procedure.
Hepatic impairment
Manufacturer advises avoid in hepatic failure (no information available).
Renal impairment
Avoid in renal failure (no information available). M
Medicinal forms
Clinical governance
**Author:** MedNext Clinical Team. **Clinical reviewer:** Dr Shameer Deen, MBBS, MS, MRCS. **Sources:** BNF, Indian Pharmacopoeia, CIMS India. **Correction:** Report errors at support@mednext.academy.
Inside MedNext for this topic
- 411 MedNext-authored chapters
- 80,000+ MCQ bank
- 15 study modes
- Growing visual cheat sheets
Study modes
- Notes
- MCQ
- Audio
- Video
- Visual
- 3D Anatomy
- Trace
- Flashcards
- Mnemonics
- Image Bank
- Clinical
- Microscopy
- Audio QBank
- Cadaver
- Book Match
Continue reading
Subject HubPharmacology Hub
All pharmacology resources in one place.
Drug SchedulesIndian Drug Schedules
Schedule H, H1, X and G classifications.
FormularyBrowse all drugs
Search 1,850+ drug profiles.
Study Mifepristone in the MedNext app
Challenge yourself with targeted pharmacology MCQs on this drug class. Every explanation links back to the chapter that teaches the concept.
Start drug challengeExplore the full formulary