What medications are used to induce labor?

Your question
What medications are commonly used to induce labor? - Karen in Columbus, Ohio

The expert answers
There are several medications or chemicals used to induce or stimulate labor. Important: Any of these methods can result in hyperstimulation (hypertonus) of the uterus. For this reason, hospitalization and close fetal monitoring are mandatory. Quite often, amniotomy (breaking the bag of waters) is used immediately after or in conjunction with these substances.

Pitocin (aka "Pit"): A synthetic form of the hormone oxytocin, pitocin is administered intravenously in levels that are slowly increased until adequate contractions are produced. (Typically, "adequate labor" is defined as three contractions in a 10-minute period.)

Dinoprostone (Cervidil): This is a form of PGE2 in a 10-milligram, slow-release form. The medication is placed within the tip of a string resembling a shoelace. This is inserted into the vagina, adjacent to the cervix, and typically left there for 12 hours. The prostaglandin (PG) is released at a rate of 0.3 milligrams per hour. If hyperstimulation occurs, medical personnel can easily remove it by pulling out the string.

PGE2 Suppositories or Gel (Prepidil): Prostaglandin suppositories can be inserted and placed either beside or into the cervix. The pharmacy can use these suppositories to make a PG gel that can be smeared on the cervix. Unfortunately, the suppository first must be melted so it can be added to other ingredients, denaturing the PG and rendering it less effective. Typically, a commercially prepared product, Prepidil, is used instead. Each dose provides 0.5 milligram of PGE2 for application. Doses can be repeated every six hours until ripening is sufficient or labor begins.

Misoprostol (Cytotec): Used primarily to treat gastric (stomach) ulcers, Cytotec is a synthetic PGE1 analogue. PGE1 tends to have fewer side effects than PGE2, which at high doses can cause fever, diarrhea, and nausea. Cytotec comes in tablet form and is placed next to the cervix in doses of 25, 50, or 100 micrograms at various frequencies; the most common regimen is 25 micrograms every three or four hours until labor ensues. Currently, the FDA has not approved Cytotec for use as a labor-inducing agent. While it has been studied and seems to be effective for select patients, some hospital pharmacies are refusing to dispense Cytotec for obstetrical use. Discussion between the FDA and the American College of Obstetricians and Gynecologists (ACOG) on the use and safety of Cytotec continues.

By far, the most commonly used methods are amniotomy, either alone or along with Pitocin, or following Cervidil or Cytotec. Each patient's induction must be individualized for the safest, most efficient mode available.