Prostaglandins: Nursing pharmacology

Prostaglandins are a group of molecules released by most cells in the body that can have effects on different tissues and organs, including the uterus, where they cause cervical ripening and uterine muscle contraction.

Prostaglandins include dinoprostone, also referred to as PGE2, and misoprostol, also referred to as PGE1. Dinoprostone is a naturally occurring prostaglandin E2 that comes in the form of a gel for endocervical administration, or vaginal insert administered intravaginally.

Dinoprostone is typically used to facilitate labor by inducing cervical ripening, to induce abortion in the second trimester, or to evacuate the uterus when there’s a spontaneous abortion or intrauterine fetal death, as well as to manage a benign hydatiform mole.

Misoprostol, on the other hand, is a synthetic prostaglandin E1 analog that can be administered intravaginally and sometimes orally for cervical ripening.

It is also used to control postpartum hemorrhage, for treatment of incomplete or missed abortion, and to induce abortion when administerd with mifeprostone, a progestrone agonist.Once administered, prostaglandins stimulate secretion of collagenase in the cervix, which degrade collagen.

This increases the relative amount of water, which softens the cervix which facilitates cervical ripening. It also triggers an increase of intracellular calcium, which causes the smooth muscle cells in the uterus to contract with increased strength, frequency and duration.

The main side effects of prostaglandins are related to uterine hyperstimulation, where there’s too much contraction. This could cause painful contractions, and lead to uterine rupture and hemorrhage.

It could even restrict placental blood flow, resulting in abnormal fetal heart rate patterns. Other side effects include nausea, vomiting, diarrhea, and diaphoresis.

Finally, some serious but luckily rare side effects include cardiac arrhythmias, disseminated intravascular coagulation, and amniotic fluid embolism.Prostaglandins are contraindicated when there’s a pelvic infection or sepsis, as well as the presence of fetal cephalopelvic disproportion, unfavorable fetal position, placenta previa, and any other obstetric emergencies that could require surgical intervention.

They are also contraindicated if there’s a history of cesarean birth or other uterine surgery because of the risk of uterine rupture.

Prostaglandins should also be avoided in those with grand multiparity, meaning they’ve given birth 5 or more times. Finally, prostaglandins must be used with caution in clients with asthma, glaucoma, or hepatic, renal, respiratory, or cardiovascular disease, since they can exacerbate these conditions.Now, before administering prostaglandins for cervical ripening, ensure there are no contraindications or preexisting conditions to receiving prostaglandins.

Then, verify that the obstetrician or midwife has provided information to the client about the medication and how it is used.

Reinforce information regarding the benefits and risks of cervical ripening as needed. Next, identify the fetal lie and presentation to ensure there’s a favorable fetal position for induction, assess the status of the cervix, assess uterine activity and obtain a baseline fetal heart rate or FHR.Registered nurses with additional training and demonstrated competence can safely administer dinoprostone for cervical ripening.

If you are using a controlled release vaginal insert, remember that it needs to stay frozen until it’s used, so bring it to the bedside as soon as you and the client are ready for administration.

Insert the mediation intravaginally, positioning it transversely in the posterior fornix. After administration, instruct the client to remain in a supine position for at least 2 hours, and let them know that the insert will stay in place for up to 12 hours or when active labor begins, whichever comes first.If a vaginal gel is used, bring it to room temperature just before administration.

It’s important not to speed up the warming process by using a warm water bath or other source of external heat.Use the provided applicator to place the gel into the cervical canal just below the level of the internal os.

After administration, instruct the client to remain in a supine position for at least 15 to 30 minutes to prevent leakage of the gel.Once the dinoprostone is in place, monitor the client’s vital signs, uterine activity and the FHR.

Finally, evaluate the desired therapeutic responses such softening of the cervix, minimal uterine activity, and normal FHR; and for undesired outcomes such as failure for the cervix to ripen, uterine hyperstimulation, indeterminate or abnormal FHR patterns, as well as any side effects.

Now, misoprostol is only available as an unscored tablet, because it’s primarily approved for use in the U.S. to treat NSAID-induced gastric ulcers.

If you are using misoprostol for cervical ripening, which is an off-label use, a good practice is to have the pharmacy prepare the dose, since the tablet is unscored and you’ll only need one quarter of the tablet to place in the vaginal fornix.

After administration, monitor the client as with other cervical ripening interventions; additionally, be sure to have terbutaline, a tocolytic, readily available in the event of uterine hyperstimulation.If you are using misoprostol to control postpartum hemorrhage, administer the medication PO, sublingually, or rectally.

Teach the client that the medication will cause their uterus to contract, and to report any side effects such as uncomfortable contractions, nausea, vomiting, diarrhea, fever, and chills.Provide comfort measures as needed.

Monitor vital signs and for the occurrence of side effects. Finally, evaluate for the therapeutic response of increased uterine tone and decreased bleeding; and for undesired outcomes such as continued hemorrhage and the occurrence of side effects.

After medication administration, be sure to document your interventions, and the client’s response, including any adverse reactions.Alright, as a quick recap… prostaglandins are molecules that are released by most cells in the body.

In the cervix, they help degrade collagen leading to cervical ripening, and in the uterus, they lead to increased frequency, duration and strength of contractions.

Prostaglandins have a number of indications, including cervical ripening, inducing abortion, evacuating the uterus after spontaneous abortion, and controlling postpartum hemorrhage.Potential side effects include uterine hyperstimulation, abnormal fetal heart patterns, nausea, vomiting, diarrhea, and diaphoresis.In rare circumstances, complications such as cardiac arrhythmia or amniotic fluid embolism may occur.

There are a number of contraindications that should be considered before administering prostaglandins, including grand multiparity, previous cesarean section, unfavorable fetal position,