Mifegyne (Mifepristone)

Mifegyne is a progesterone receptor antagonist used in early pregnancy management.

• Medical termination of intrauterine pregnancy: induces abortion in early gestation under medical supervision.
• Cervical ripening prior to surgical abortion: softens the cervix to facilitate operative procedures.
• Management of early pregnancy loss: assists in expelling retained products of conception.

• Mifepristone binds competitively to progesterone receptors in the uterus, blocking the hormone's action. This antagonism leads to decidual breakdown, detachment of the gestational sac, and cervical softening, thereby facilitating the expulsion of pregnancy tissue when used in combination with a prostaglandin analogue.

Mifegyne may cause a range of adverse reactions.

Common Side Effects

• Nausea: mild to moderate stomach upset.
• Vaginal bleeding: variable intensity, often heavier than a normal period.
• Cramping: uterine pain associated with tissue expulsion.
• Fatigue: general tiredness during the process.

Serious or Rare Side Effects

• Severe infection: signs include fever, foul discharge, or abdominal pain.
• Heavy hemorrhage: excessive blood loss requiring medical attention.
• Allergic reaction: rash, itching, swelling, or difficulty breathing.

Mifegyne requires careful patient assessment and monitoring.

• Confirm gestational age: ensure pregnancy is within approved limits (typically ≤10 weeks).
• Exclude ectopic pregnancy: rule out non‑uterine implantation before use.
• Assess contraindications: avoid in patients with chronic adrenal failure or long‑term corticosteroid therapy.
• Provide follow‑up: schedule post‑treatment evaluation to confirm complete abortion.
• Store at ambient temperature: keep below 25°C, in original packaging, protected from moisture and light.

Mifegyne can interact with other medicines that affect its metabolism or uterine activity.

Major Interactions (Avoid)

• CYP3A4 inducers (e.g., rifampin, carbamazepine): may reduce mifepristone effectiveness.
• Antifungal azoles (e.g., ketoconazole): may increase plasma concentrations, raising risk of adverse effects.

Moderate Interactions (Monitor Closely)

• Anticoagulants (e.g., warfarin): may enhance bleeding risk.
• NSAIDs: may increase uterine cramping.
• Hormonal contraceptives: may be less effective during treatment.