First-lineMifegyne

Mifepristone

Selective progesterone receptor modulator (antiprogestin)

Primes the pregnancy for misoprostol — medical TOP and miscarriage.

Oral

First-line for

  • Medical termination of pregnancy (up to 24 weeks)
  • Management of missed/incomplete miscarriage

Mechanism

Competitive progesterone receptor antagonism → decidual breakdown, ↑ uterine PG sensitivity, cervical softening.

“M&M” combo

  • Mifepristone day 1 → Misoprostol 24–48 h later
  • M primes, M expels

Dosing

EMA (≤10 wks)
200 mg PO, misoprostol 24–48 h later
Missed miscarriage
200 mg PO, misoprostol 48 h later

Contraindications

  • AbsoluteChronic adrenal failure
  • AbsoluteSuspected ectopic pregnancy
  • AbsoluteInherited porphyria, long-term corticosteroid therapy

Side effects

  • Nausea, cramping, light bleeding
  • Headache, fatigue
  • Rarely: rash

Fetal & maternal notes

  • If pregnancy continues after exposure — increased risk of malformations; offer surgical completion.

Key interactions

  • NSAIDs

    OK

    Do NOT reduce efficacy — co-prescribe for pain

  • CYP3A4 inhibitors/inducers

    Caution

    Alter mifepristone levels

Clinical pearls

  • 💡 Anti-D required for Rh-negative women >10 weeks.
  • 💡 Confirm completion with hCG fall or USS.

Content last reviewed: REPLACE_ME (e.g. 2026-07)

Spotted something out of date? See our disclaimer or use Report an Error above.

For educational use only

Not medical advice. Verify dosing against the BNF and your local trust guidelines before prescribing.