MTP Kit (Mifepristone + Misoprostol)

Composition

Mechanism of Action

Mifepristone (Antiprogestin)

• Analog of the progestin norethindrone with strong affinity for the progesterone receptor, but acts as an antagonist - blocks natural progesterone
• Causes decidual breakdown, cervical softening, and sensitizes the uterus to prostaglandins
• Also has anti-glucocorticoid properties (used in Cushing syndrome at higher doses)

Misoprostol (Prostaglandin E1 analogue)

• Causes uterine contractions and further cervical ripening
• Expels the pregnancy
• Can be administered buccally, vaginally, or sublingually
• Misoprostol alone (800 mcg vaginally, repeated at 24 hours) achieves complete abortion in ~91% of cases up to 56 days - less effective than the combination

• Berek & Novak's Gynecology, p. 781

Approved Gestational Limit

• FDA (USA): Up to 70 days (10 weeks) from the last menstrual period (updated 2016 label)
• India (MTP Act): Medical abortion (Mifepristone + Misoprostol) recommended for gestational age up to 9 weeks; overall MTP legal up to 20 weeks (one RMP opinion), 20-24 weeks for special categories (two RMP opinions), and no upper limit for severe fetal anomalies (Medical Board approval required per 2021 Amendment)

Regimen (Updated FDA-Approved Protocol)

1. Day 1: Mifepristone 200 mg orally in the clinic
2. Day 2-4 (24-72 hrs later): Misoprostol 800 mcg buccally or vaginally - can be self-administered at home
3. Day 14 (~2 weeks): Follow-up to confirm complete abortion (clinical assessment or ultrasound); bleeding and cramping alone do NOT confirm successful termination

Note: The original FDA protocol used mifepristone 600 mg + misoprostol 400 mcg orally on day 3 only. The current 200 mg dose is equally effective with fewer GI side effects.

Contraindications

• Confirmed or suspected ectopic pregnancy
• IUD in place (must be removed first)
• Chronic adrenal failure
• Concurrent long-term corticosteroid therapy
• Allergy to mifepristone, misoprostol, or other prostaglandins
• Hemorrhagic disorder or anticoagulant therapy
• Inherited porphyrias
• Berek & Novak's Gynecology, p. 781

Side Effects & Complications

When to Seek Emergency Care

• Fever >100.4°F (38°C) lasting >4 hours
• Soaking through 2 thick sanitary pads/hour for 2 consecutive hours
• Severe abdominal pain or "feeling sick" (weakness, nausea, vomiting, diarrhea) >24 hours after misoprostol

Surgical Intervention Rate

Failure & What to Do

• Fails in approximately 5-8 in 100 women (incomplete or continuing pregnancy)
• If pregnancy continues, teratogenic risk exists - surgical termination should be offered
• Incomplete abortion requires surgical curettage

Infection Risk

• After case reports of fatal Clostridium sordellii infection, prophylactic doxycycline 100 mg BD x 1 week and buccal (not vaginal) misoprostol is recommended by some centers
• The Society of Family Planning does not require universal antibiotics, but individual practitioners may prescribe them

MTP Act (India) - 2021 Amendment Key Points

• Consent: Only the woman's own written consent needed (≥18 yrs); guardian's consent for minors or mentally ill
• Unmarried women now included under contraceptive failure clause (2021 Amendment)
• Privacy clause: RMP cannot reveal woman's identity - punishable offense
• The Essentials of Forensic Medicine and Toxicology, 36th ed. (2026)

Alternative When Mifepristone Unavailable

• Misoprostol alone: 800 mcg vaginally, repeated at 24 hours - complete abortion in 91% up to 56 days
• Methotrexate + Misoprostol: Effective but slower than mifepristone regimen