In medication abortion, drugs are used to replace the uterine aspiration for the termination of a pregnancy. The two pills that are used for terminating an abortion are misoprostol and mifepristone. A complete abortion determines the effectiveness of the medicine, and no other treatment is needed. For the most effectiveness, the combination of mifepristone and misoprostol should be preferred to misoprostol alone for medical abortion (Creinin et al., 2007). In contrast, a regimen of misoprostol alone without the presence of mifepristone is also safe to use. The women are advised to take these drugs in the early stages of pregnancy and not earlier than nine weeks. The mechanism of action of mifepristone and misoprostol is very significant, and their safety in home use should be explored in the absence of a healthcare provider, as pregnancy is a sensitive life stage.
Mifepristone is an antagonist of glucocorticoid and progesterone receptors, which causes the process. It is an orally active progesterone antagonist between 100 mg and 200 mg (Elami-Suzin et al., 2013). At reduced dosages, mifepristone selectively competes with progesterone by substituting it for its intracellular receptor. In addition, it blocks cortisol and the glucocorticoid receptor in higher amounts. The mechanism of action involves the hypothalamic-pituitary-adrenal axis, which enhances the cortisol level. Mifepristone does this by blocking the progesterone necessary to prepare the endometrium for implantation and making the body more sensitive to prostaglandins. In this way, the hormone helps to achieve this state by stimulating its synthesis and inhibiting metabolism (Von Hertzen et al., 2009). Prostaglandin rising, thus, will lead to endometrial disruption as a result of menstrual bleeding. This, at last, causes the process to come to an end. On the other hand, misoprostol is characterized by different mechanisms of action via synthesizing a prostaglandin analog that suppresses both basal and nocturnal gastric acid secretion. The medications bind to prostaglandin receptors present in the parietal cells of the stomach (Dabash et al., 2015). It achieves this by reducing the generation of gastric acid and enhancing mucus and bicarbonate secretions while causing swelling and the accumulation of mucosa and submucosa. Therefore, the layer becomes a thicker mucosal bilayer to prevent hydrogen ion reflux and maintain the regulation of mucosal blood (Creinin et al., 2007). Hence, the mucosa does not continue to renew the cells. At the uterotonic level, misoprostol will bind to the smooth cells found on the inner surface of the uterus. This is the feature that sets it apart from the rest and makes it capable of aborting an unwanted pregnancy and inducing labor and cervical ripening. Consequently, collagen in the connective tissue is broken down, causing cervical dilation (Elami-Suzin et al., 2013). As the drug begins to act, the cervical tone is reduced, and the contractions become more powerful and frequent, resulting, in the end, in the release of the pregnancy tissue from the uterus.
Most of the time, it is given in the presence of a healthcare provider and is usually the first drug to be taken. After it is attached, it will bind to the uterine wall, which will become soft, open the cervix, and separate the placenta from the uterine lining. Mifepristone will be given 24 or 48 hours before misoprostol (Von Hertzen et al., 2009). The patients will either visit the health facility or receive home-based care. The drug is given to cause the contraction of the uterus to expel its contents. Specific adverse effects are related to mifepristone, like headache, fatigue, abdominal pain, and pelvic pain. The individual might also have an irregular menstrual cycle. The use of misoprostol can also cause short-term side effects like diarrhea and stomach ache which usually disappear on their own (Dabash et al., 2015). There is also a possibility for the condition to be accompanied by fever and chills.
In conclusion, medication pills containing mifepristone and misoprostol are efficient tools in medical abortion. Mifepristone is a synthetic substance that minimizes the role of progesterone in the development of a pregnancy. Misoprostol, which is a prostaglandin analog, causes uterine contractions to push out the contents. The medications need to be taken 24-48 hours apart, starting with mifepristone.
Creinin, M. D., Schreiber, C. A., Bednarek, P., Lintu, H., Wagner, M. S., Meyn, L. A., & Medical Abortion at the Same Time (MAST) Study Trial Group. (2007). Mifepristone and misoprostol administered simultaneously versus 24 hours apart for abortion: a randomized controlled trial. Obstetrics & Gynecology, 109(4), 885-894. 10.1097/01.AOG.0000258298.35143.d2
Dabash, R., Chelli, H., Hajri, S., Shochet, T., Raghavan, S., & Winikoff, B. (2015). A double-blind, randomized controlled trial of mifepristone or placebo before buccal misoprostol for abortion at 14–21 weeks of pregnancy. International Journal of Gynecology & Obstetrics, 130(1), 40–44. 10.1016/j.ijgo.2015.02.023
Elami-Suzin, M., Freeman, M. D., Porat, N., Rojansky, N., Laufer, N., & Ben-Meir, A. (2013). Mifepristone followed by misoprostol or oxytocin for second-trimester abortion: a randomized controlled trial. Obstetrics & Gynecology, 122(4), 815-820. 10.1097/AOG.0b013e3182a2dcb7
Von Hertzen, H., Piaggio, G., Wojdyla, D., Marions, L., My Huong, N. T., Tang, O. S., … & WHO Research Group on Post‐ovulatory Methods of Fertility Regulation. (2009). Two mifepristone doses and two intervals of misoprostol administration for termination of early pregnancy: a randomized factorial controlled equivalence trial. BJOG: An International Journal of Obstetrics & Gynaecology, 116(3), 381–389. 10.1111/j.1471-0528.2008.02034.x