Mifepristone

It is a steroidal antiprogestin and antiglucocorticoid acting at the receptor level. It is used in combination with a prostaglandin such as misoprostol for termination of pregnancy. It is a synthetic 19-nonsteroidal related to norethinodrone. It binds to the intracellular progesterone receptor where it competitively inhibits progesterone attachement and thus antagonizes the effects of endogenous progesterone.

Indications

Termination of early pregnancy in combination with prostaglandins. Termination of pregnancy during trimester II and III. Inductions of labour in the case of foetus mortus. Immediates post-coital emergency contraception. Contraception with continuous/intermittent administration. Progesterone dependent malignancies, breast cancer, meningioma. Endometriosis, Uterine leiomyoma, Induction of normal labour, Extrauterine pregnancy, Induction of menses (once a month administration).

Dosage

For termination of pregnancy (49 days or less duration) : Oral : 600mg (three 200mg tablets) as a single oral dose followed two days later by 400 micrograms (mcg) (two 200mcg tablets) of misoprostol as a single oral dose. Cervical ripening : Preoperative treatment with mifepristone 50-600mg, 24 -30h before surgery. Postcoital contraception:Oral :Single dose of 600mg within 72 hours of unprotected intercourse. Contraceptive : 2-5mg per day for 30 days inhibits ovulation and delays menstruatio

Contra-Indications

Confirmed or suspected ectopic pregnancy, Chronic adrenal failure, Concurrent long-term corticosteroid therapy, History of allergy to mifepristone, misoprostol or other prostaglandin, Hemorrhagic disroders or concurrent anticoagulant therapy, Inherited porphyrias.

Special Precautions

In some cases excessive bleeding may require treatment. Patients should be followed up after 14 days for the confirmation of termination of pregnancy. Women with cardiovascular, hepatic, renal, hypertensive should be treated with caution, also women above 35 yrs and who smoke should be treated with caution.

Side Effects

Excessive vaginal bleeding, unusual tiredness or weakness, uterine cramping, back pain, diarrhea, dizziness, headache, nausea, vomiting, dyspepsia, anxiety, belching, cough, fever, flu-like symptoms, heartburn, increased clear or white vaginal discharge, itching of the vagina or genital area, fatigue, pain during sexual intercourse, pain or tenderness around eyes and cheekbones, pale skin, shortness of breath, insomnia, tightness of chest or wheezing unusual bleeding or bruising sinusitis, uteri

Drug Interactions

Ketoconazole, itraconazole, erythromycin, and grapefruit juice inhibit mifepristone, metabolism. Rifampin, dexamethasone, St. John's Wort, and certain anticonvulsants (phenytoin, phenobarbital, carbamazepine, induce mifepristone metabolism.