Bill Wightkin, PharmD, MS 480.219.6167 wwightkin@atsu.edu Abortifacients Bill Wightkin, PharmD, MS 480.219.6167 wwightkin@atsu.edu Reviewed 6.9.17

Learning Objectives Describe the mechanisms of action of mifepristone, misoprostol, dinoprostone and carboprost when used for elective and therapeutic abortions (slides 6, 9, 10, 12) Explain the various indications for the obstetrical use of misoprostol (slide 11)

A Pregnancy Loss B Spontaneous C Recurrent D Uterine Factors E Medical Conditions F Endocrine G Autoimmune H Chronic Illness I Genetic / Environmental J Psychological K Therapeutic Abortion 6.11.10

© World Health Organization 2012.

Mifepristone (RU-486): A progesterone receptor antagonist Progesterone is crucial for maintenance of the endometrium during pregnancy. Blockade of progesterone action by mifepristone results in decay and death of the decidua. Lack of nourishment from the decidua causes the blastocyst to die and detach from the uterus. Usually combined w/ misoprostol which stimulates uterine contraction. Combination >= 95% effective in term 1st trimester pregnancies. In fact, mifepristone increases uterine sensitivity to prostaglandins. Major adverse effect not from drug but from excessive vaginal bleeding that can occur from subsequent abortion

MISOPROSTOL Information from Last Year’s GI Course

Misoprostol (CYTOTEC) Pharmacology MISOPROSTOL Information from Last Year’s GI Course Misoprostol (CYTOTEC) Pharmacology Synthetic analog of PGE1 Promotes gastric mucus and mucosal bicarbonate secretion Inhibits basal and nocturnal gastric acid secretion from parietal cells Misoprostol Adverse Effects Diarrhea (dose dependent) Abdominal cramping, flatulence

N Engl J Med 2007;357:477-87.

Prostaglandins (E1, E2, F2 α ): stimulate uterine contraction MISOPROSTOL: analog of PG E1

Obstetrical Uses of Misoprostol Available ONLY as a tablet originally intended just for oral use: given orally, vaginally or rectally (doses differ based on route and reason for use) Uses Abortifacient “Ripen” cervix prior to labor Induce labor Treat postpartum hemorrhage

Other Prostaglandin Abortifacients Carboprost: analog of naturally occurring prostaglandin F2α OTHER USE: Treatment of postpartum hemorrhage due to uterine atony OTHER USE: Dinoprostone vaginal suppository (prostaglandin E2) (Prostin E2) is indicated for evacuation of the uterine contents in the management of missed abortion or intrauterine fetal death.

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