What is Mifepristone and Misoprostol Used For?|Dosage, Side Effects, Contraindications of Mifepristone and Misoprostol

There is a lot of apprehension about medicines used for terminating a pregnancy. This article deals with details of what mifepristone and misoprostol is used for, their dosage, side effects and contraindications.

Mifepristone and misoprostol are the medicines usually used together to terminate a pregnancy.¹ Mifepristone is found to reduce the side effects of misoprostol and also decreases the duration between induction and abortion. Thus facilitates easy termination and the rate at which the continuation of pregnancy is decreased.

Medical termination of pregnancy is also referred to as abortion. It is legal and also considered as humane way of killing fetus in view of many factors which includes health of mother, kind of pregnancy, position of placenta, history of hereditary syndromes, etc.

It is important to know the dosage, side effects and contraindications of mifepristone and misoprostol to be able to take an informed decision about using it with medical guidance.

Let us begin with an understanding of how these medicines act and cause abortion.

Mifepristone pills are usually taken by mouth whereas misoprostol can be oral or vaginal or sometimes it is made to dissolve in saliva in buccal cavity. First mifepristone is given orally and then misoprostol is given within 48 hours of taking mifepristone.

Action of Mifepristone. Mifepristone which is also known as RU-486, Mifegyne, Mifeprex is antagonistic in nature and affects the function of progestin hormone receptor. The different stages of its effect are listed below.

• As a first step, it separates placenta and endometrium
• Cervix becomes soft and dilate
• Contraction of uterus

Action of Misoprostol. Misoprostol is also known by Misoprostolum, Misoprostil, cytotec, isprelor which is used as antiulcer in case of ulcers caused as side effect of NSAIDs, reduce the production of gastric juice and an enzyme called pepsin. It is also used as an abortifacient agent to end the pregnancy with early stages of gestation. Usage of this drug vaginally works at a faster rate whereas buccally or oral one gives the same effect. It works in the following way.

• Uterus contracts
• Vaginal bleeding starts within 4 hours of taking misoprostol
• Cramping
• Pregnancy ends within 24 hours

• The dose of mifepristone and misoprostol is important and depends on the time and stage at which it is taken.
• Mifepristone usually of 200mg is taken by a pregnant woman who wants abortion before 9 to 10 weeks of gestation.
• Misoprostol usually of 800 mcg is used after 6 hours to 48 hours of swallowing of mifepristone.
• Misoprostol is given for the second time if the process is unsuccessful in the first trial. Maximum of 5 doses of misoprostol can be taken if the previous tablets do not work efficiently.

The process is continued with surgical way if the above procedures do not result in successful abortion. This is because, both mifepristone and misoprostol cause congenital disorders and abnormalities in the fetus if it survives. The surgeries in this condition may be undertaken by manual aspiration or D & C (Dilatation and Curettage).

The combination can also be used in case of gestation above 14 weeks. It should be done under medical supervision as the risks are more. The doses include swallowing of mifepristone of 200 mg, then vaginal insertion of misoprostol of 800 mcg between 12 to 48 hours, then at regular interval of 3 hours until the occurrence of abortion.

In case, if the abortion does not take place with this, another course of mifepristone and misoprostol is repeated after 3 hours of the previous dose of misoprostol.
In case, if the mifepristone is unavailable, misoprostol can be taken alone with a different dosage at regular interval of 3 hours like, 800 mcg in the beginning and then continued with 400 mcg until termination begins.

In the third trimester, some records tell us that using misoprostol alone can cause the termination of pregnancy without much difficulty.

Side effects of this medicine may not be common to all women. However, some of the possible side effects of mifepristone and misoprostol include the following ² .

• Dizziness
• Nausea
• Diarrhea
• Vomiting
• Weakness
• Bleeding would be heavier than in usual menstrual cycle
• Cramps
• Postmenopausal vaginal bleeding

All the above listed side effects would be normally expected during the treatment. In case if anyone of these symptoms or all of they persist for longer duration with or without abdominal pain, fainting, increased heartbeat, the individuals should seek medical advice immediately.

There are some contraindications of mifepristone and misoprostol too. The conditions where the doctor has to take care before using these medicines are as follows.

• In case of ectopic pregnancy, an abnormal condition of pregnancy where the development of embryo takes place outside the womb, usage of these pills causes rupture but ends with severe bleeding which is undesirable. Hence the intrauterine contraceptive device must be removed first before using the above combination.
• Misoprostol is not advised before caesarian or uterus surgery since it causes serious bleeding.
• Mifepristone is not suitable in pregnancy in fallopian tube or if the uterine lining has grown beyond normal size.
• It is not advisable to use mifepristone in cases where potassium level is low in the blood or if the patient is suffering from any metabolic disorder related to liver, uterine cancer, under activity of adrenal gland.
• Mifepristone and misoprostol are not advised for women who are under long term corticosteroid therapy.
• In case if the patients already have bleeding problems, mifepristone is not recommended.
• Misoprostol is not given to address ulcers caused by nonsteroidal anti-inflammatory drugs if the patient is pregnant as it may cause abortion, rupture of uterus or premature birth and/or babies with congenital diseases.
• Even though there are little records regarding the effect of misoprostol in infants who are breast feeding, since some traces of this drug are found in breast milk, it is better to avoid for nursing mothers.
• The combination is not used for anemic patients and those who have less immunity.

Though both mifepristone and misoprostol are used to terminate pregnancy, it is used together or separately. In a few cases, mifepristone is not sufficient to cause abortion they are mostly used as combination. The ways to take this medicine, their relevant uses and their dosage is best decided by the treating physician. Though misoprostol is used for treating ulcers caused by some other drugs, care should be taken not to advice to pregnant women. Either it may cause abortion or if child survives, causes birth defects. The combination can be given in all the periods of gestation in different doses but complications increase as the pregnancy progresses. Also, while prescribing the medicine, the health issues if present are to be considered, particularly because of the possible side effects and contraindications.

Reference:

1. https.//www.ncbi.nlm.nih.gov/pubmed/12101864
2. https.//www.ncbi.nlm.nih.gov/pubmed/14989987