MIF

As a medical alternative to surgical termination of intra-uterine pregnancy in early pregnancy: 600 mg Mifepristone in a single oral dose followed 36-48 hrs later, by the administration of a prostaglandin analogue Misoprostol 400 mcg orally (up to 49 days) or Gemeprost 1 mg vaginally (up to 63 days). 

Softening and dilatation of the cervix uteri prior to surgical pregnancy termination: 200 mg Mifepristone, followed 36-48 hrs later (but not beyond) by a surgical termination of pregnancy. 

Preparation for the action of prostaglandin analogues in the termination of pregnancy for medical reasons (to reduce the doses of prostaglandin): 600 mg of Mifepristone taken in a single oral dose, 36-48 hrs prior to scheduled prostaglandin administration which will be repeated as often as indicated. 

Labour induction for expulsion of a dead fetus (fetal death in utero): 600 mg of Mifepristone in a single oral daily dose for 2 consecutive days. Mifepristone alone leads to expulsion in about 60%. Labour should be induced by the usual methods if it has not started within 72 hrs following the first administration of Mifepristone.

It is very common for women to experience uterine contractions or cramping (10-45%) in the hours following prostaglandin intake. Bleeding increases with gestational age. Heavy bleeding occurs in about 5% of cases and from 0-1.4% may require haemostatic curettage. Uterine rupture, hypotension, skin rashes, urticaria, hot flashes and dizziness have been uncommonly reported.

Single doses of Mifepristone up to 2 gm caused no unwanted reaction. In the event of massive ingestion, signs of adrenal failure might occur. Acute intoxication may require admission to hospital and if relevant treatment with dexamethasone.

Mifepristone is indicated:

• As a medical alternative to surgical termination of intra-uterine pregnancy
• Softening and dilatation of the cervix uteri prior to surgical pregnancy termination
• Preparation for the action of prostaglandin analogues in the termination of pregnancy for medical reasons
• Labour induction for the expulsion of a dead fetus (fetal death in utero).

Mifepristone is a synthetic steroid which blocks the effects of progesterone by competitively binding to the intracellular progesterone receptor. It sensitises the myometrium to the contraction-inducing action of prostaglandin. At higher doses, it blocks the effect of cortisol at the glucocorticoid receptor while increasing circulating cortisol concentrations.

Mifepristone is available only in single dose packaging. Administration must be under the supervision of a qualified physician. There are no data on the safety and efficacy of Mifepristone in women with chronic medical conditions such as cardiovascular, hypertensive, hepatic, respiratory or renal disease; insulin-dependent diabetes mellitus; severe anemia or heavy smoking. Women who are more than 35 years of age and who also smoke 10 or more cigarettes per day should be treated with caution because such patients were generally excluded from clinical trials of Mifepristone. Although there is no clinical evidence, the effectiveness of Mifepristone may be lower if Misoprostol is administered more than two days after Mifepristone administration.

Drugs acting on the Uterus