Myomectomy
When administered prior to myomectomy in women with uterine fibroids, misoprostol reduces operative blood loss and requirement of blood transfusion. Abortion
Misoprostol is used either alone or in conjunction with another medication (mifepristone or methotrexate) for medical abortions as an alternative to surgical abortion. Medical abortion has the advantage of being less invasive, and more autonomous, self-directed, and discreet. It is preferred by some women because it feels more "natural," as the drugs induce a miscarriage. It is also more easily accessible in places where abortion is illegal. The World Health Organization provides clear guidelines on the use, benefits and risks of misoprostol for abortions.Misoprostol is most effective when it is used in combination with methotrexate or mifepristone (RU-486). Mifepristone inhibits the signals of pregnancy hormones, eventually causing the uterine lining to degrade, similar to a period, which cause the embryo to detach from the uterus walls. Misoprostol then dilates the cervix and induces muscle contractions which clear the uterus. Misoprostol alone is less effective (typically 88% up to eight-weeks gestation). It is not inherently unsafe if medically supervised, but 1% of women will have heavy bleeding requiring medical attention, some women may have ectopic pregnancy, and the 12% of pregnancies that continue after misoprostol failure are more likely to have birth defects and are usually followed up with a more effective method of abortion.Most large studies recommend a protocol for the use of misoprostol in combination with mifepristone. Together they are effective in around 95% for early pregnancies.
Bleeding and cramping is likely to be greater than that experienced with menses, however, emergency care is advised if bleeding is excessive.Misoprostol should not be taken by pregnant women with wanted pregnancies to reduce the risk of NSAID-induced gastric ulcers because it increases uterine tone and contractions in pregnancy, which may cause partial or complete abortions, and because its use in pregnancy has been associated with birth defects.All cervical ripening and induction agents can cause uterine hyperstimulation, which can negatively affect the blood supply to the fetus and increases the risk of complications such as uterine rupture. Concern has been raised that uterine hyperstimulation that occurs during a misoprostol-induced labor is more difficult to treat than hyperstimulation during labors induced by other drugs. Because the complications are rare, it is difficult to determine if misoprostol causes a higher risk than do other cervical ripening agents. One estimate is that it would require around 61,000 people enrolled in randomized controlled trials to detect a difference in serious fetal complications and about 155,000 people to detect a difference in serious maternal complications. Contraindications
It is recommended that medical treatment for missed abortion with misoprostol should only be considered in people without the following contraindications: suspected ectopic pregnancy, use of non-steroidal drugs, signs of pelvic infections or sepsis, unstable hemodynamics, known allergy to misoprostol, previous caesarean section, mitral stenosis, hypertension, glaucoma, bronchial asthma, and remote areas without a hospital nearby. Pharmacology
Mechanism of action
Misoprostol, a prostaglandin analogue, binds to myometrial cells to cause strong myometrial contractions leading to expulsion of tissue.