Mifepristone + Misoprostol

Generic Details

Generic Name

Mifepristone-Misoprostol

Other Names

  • RU-486
  • Mifeprex
  • Mifegyne
  • Cytotec

Drug Class

  • Antiprogestin
  • Prostaglandin E1 Analog

Chemical Formula

C29H35NO2 (mifepristone), C22H38O5 (misoprostol)

Molecular Weight

429.60 g/mol (mifepristone), 382.54 g/mol (misoprostol)

Mechanism of Action

  • Mifepristone: Blocks progesterone receptors leading to endometrial decidual degeneration and cervical softening
  • Misoprostol: Causes uterine contractions and cervical ripening

Indications

  • Medical termination of early pregnancy (up to 70 days gestation)

Common Dosage Forms

  • Tablet

Typical Dosage

  • 200 mg mifepristone orally followed by 800 mcg misoprostol buccally or vaginally 24-48 hours later

Pediatric Dosage

Not established

Geriatric Dosage

Use with caution and adjust dosage based on individual patient requirements

Side Effects

  • Cramping
  • Bleeding
  • Nausea
  • Vomiting
  • Diarrhea
  • Fever
  • Chills

Contraindications

  • Confirmed or suspected ectopic pregnancy
  • Chronic adrenal failure
  • Long-term corticosteroid therapy
  • Hemorrhagic disorders
  • Inherited porphyria
  • Allergy to mifepristone or misoprostol

Pregnancy Category

  • X - Contraindicated in pregnancy for termination purposes

Lactation Safety

Not recommended during breastfeeding due to potential risks to the infant

Drug Interactions

  • CYP3A4 inducers/inhibitors
  • Anticoagulants
  • Corticosteroids
  • Ketoconazole
  • Antacids containing magnesium

Overdose Symptoms

  • Excessive vaginal bleeding
  • Hypotension
  • Gastrointestinal disturbances

Antidote for Overdose

Treatment is supportive and symptomatic

Storage Conditions

  • Store at room temperature (20-25°C)
  • Protect from moisture and light

Pharmacokinetics

  • Absorption: Well-absorbed orally
  • Distribution: Extensively bound to plasma proteins
  • Metabolism: Mifepristone undergoes hepatic metabolism by CYP3A4 enzymes
  • Excretion: Primarily excreted in feces

Precautions

  • Patients with asthma
  • Cardiovascular disease
  • Hepatic impairment
  • Renal impairment

Warnings

  • Risk of serious bacterial infection if incomplete abortion occurs
  • Ultrasound confirmation of complete abortion post-treatment is recommended
  • Emergency medical care availability should be ensured before initiating therapy

Others