Mifegyne (Mifepristone)

• Mifepristone acts as a progesterone receptor antagonist and is indicated for several reproductive and endocrine conditions.
• Medical termination of intrauterine pregnancy (≤10 weeks): induces uterine decidual breakdown and expulsion of the gestational sac.
• Cushing's syndrome management: blocks peripheral glucocorticoid receptors, reducing cortisol‑mediated effects.
• Uterine fibroid treatment: decreases fibroid size and associated bleeding by antagonizing progesterone‑driven growth.

• Mifepristone competitively binds to progesterone receptors, preventing progesterone‑mediated maintenance of the endometrium and decidua, leading to decidual breakdown and detachment of the gestational sac. It also antagonizes glucocorticoid receptors, diminishing cortisol activity, which contributes to its efficacy in Cushing's syndrome and fibroid reduction.

Common Side Effects

• Nausea or vomiting.
• Abdominal cramping or pelvic pain.
• Vaginal bleeding or spotting.
• Fatigue or headache.
• Diarrhea.
• Dizziness.

Serious or Rare Side Effects

• Severe hemorrhage requiring medical intervention.
• Infection or sepsis after incomplete evacuation.
• Allergic reactions including rash, angioedema, or anaphylaxis.
• Liver enzyme elevation or hepatic dysfunction.
• Uterine rupture (rare).
• Persistent gestational tissue leading to prolonged bleeding.

• Mifepristone should be used only after confirming eligibility and gestational age.
• Confirm gestational age: ensure pregnancy is ≤10 weeks before administration.
• Assess contraindications: exclude ectopic pregnancy, chronic adrenal insufficiency, anticoagulant therapy, or severe anemia.
• Monitor for infection: watch for fever, foul discharge, or abdominal tenderness.
• Ensure follow‑up: schedule ultrasound to verify complete uterine evacuation.
• Avoid use in breastfeeding: contraindicated due to potential fetal exposure.
• Store at ambient temperature (below 25 °C): keep in the original pack, protect from moisture and light.

Mifepristone may interact with several drug classes.

Major Interactions (Avoid)

• Anticoagulants (e.g., warfarin): increased risk of severe bleeding.
• Systemic corticosteroids: may diminish efficacy in Cushing's syndrome.
• Rifampin: induces hepatic enzymes, reducing mifepristone plasma levels.

Moderate Interactions (Monitor Closely)

• Antifungal agents (e.g., ketoconazole): may raise mifepristone concentrations.
• Anticonvulsants (e.g., phenytoin): may alter drug metabolism.
• NSAIDs: may exacerbate gastrointestinal discomfort.