Dinoprostone - Indications, Contraindications, and Side Effects

Introduction

Labor induction or inducing labor is a common procedure in pregnancy during which the uterus is prompted to contract before the labor begins on its own. It is an artificial way of stimulating the uterus to begin uterine contractions. It is recommended for various reasons, such as labor not beginning even after a water break occurs, stillbirth in the past, the baby showing signs of stress, gestational diabetes, or hypertension that may threaten the baby’s health, or during post-term pregnancy. Some of the medications used to induce labor include Oxytocin, Misoprostol, and Dinoprostone.

What Is Dinoprostone?

Dinoprostone belongs to a group of drugs known as prostaglandins. It is similar to the natural substance released in the body when labor is about to begin. Dinoprostone is mainly indicated to start or continue cervical ripening in pregnant women who are near term or have completed their full term of pregnancy, termination of pregnancy, or having certain complications that may harm the fetus. It is available as a gel or vaginal suppository for extended-release. This drug was first synthesized in 1970 but approved for medical use by the United States Food and Drug Administration (USFDA) in 1977. It is also used for the management of intrauterine death or evacuation of uterine contents during a missed abortion up to 28 weeks.

How Is Dinoprostone Administered?

Dinoprostone can be administered vaginally as an insert, gel, or suppository. It is kept frozen (between -20 to -10 degrees Celsius) until ready for use and is administered by trained obstetrical personnel or a healthcare professional in a hospital. Patients are frequently monitored, and the drug is discontinued immediately if any severe adverse reactions are noticed.

• A Dinoprostone vaginal insert (one milligram) or gel (0.5 milligrams) is placed intravaginally (in the posterior fornix) using a syringe. A minimal amount of water-miscible lubricant may be used to assist the insertion. It must be retained for up to 12 hours, during which 0.3 mg of the drug is released per hour. After the administration, the patient must lie down for about ten minutes to two hours so that the medicine gets absorbed. The duration depends on the form of the drug administered. A second dose may be administered after six hours if the desired response is not observed. The gel is a rapid-release form compared to the vaginal insert; however, it may be less convenient as it requires frequent vaginal examinations. The drug must not be administered further if there are severe side effects, no contractions within 24 hours, or in cases of uterine hyperstimulation or uterine membrane rupture.

• Dinoprostone suppositories are used for the evacuation of uterine contents; a 20 mg suppository is inserted into the vagina once every three hours until abortion occurs. The drug must be stopped if the patient has severe side effects or if the abortion does not occur within 24 hours. If the abortion is incomplete through the suppository, dilation and curettage must be performed.

How Does Dinoprostone Work?

Dinoprostone is a prostaglandin E2 (PGE2) hormone, a naturally occurring compound found in low concentrations in the body, and is responsible for promoting labor. During pregnancy, it is continuously secreted by the placenta and fetal membranes. When administered in the vagina, it acts by thinning, softening, and dilating (opening) the cervix and causes uterine contractions progressing to labor.

What Are Some Important Instructions About Dinoprostone?

• Patients must inform the doctor if they are allergic to any medications.

• The doctor must also be informed if the patient is taking any over-the-counter drugs or nutritional, herbal, or vitamin supplements.

• Patients must inform the doctor if they have undergone any major surgeries in the past or any serious medical issues before the administration of the drug.

• Administration of Dinoprostone may be associated with a risk of disseminated intravascular coagulation (DIC) (abnormal blood clotting in the blood vessels) during the postpartum period, especially in women above 30 years or if the gestation is over 40 weeks.

• Dinoprostone can cause an increase in intraocular pressure and constriction of pupils.

• Patients must be aware that Dinoprostone causes frequent and prolonged contractions, which might disrupt the blood flow to the fetus.

• In some patients, administration of Dinoprostone may cause the development of amniotic fluid embolism syndrome, a rare and fatal obstetric condition.

• Post-marketing studies have reported serious and life-threatening hypersensitivity reactions, which include angioedema and anaphylaxis, which occurred within minutes to hours after the administration of the gel. Therefore, caution must be exercised throughout the procedure.

What Are the Contraindications of Dinoprostone?

Dinoprostone is contraindicated in the following conditions:

• Patients with known hypersensitivity to prostaglandins or the constituents of the medicine.

• Patients with unexplained vaginal bleeding or with placenta previa (low-lying placenta which partially or completely covers the cervix).

• Patients for whom vaginal delivery or oxytocic drugs are not indicated.

• Dinoprostone must be avoided in patients with a history of asthma, epilepsy, glaucoma, acute inflammatory pelvic disease, and lung, liver, heart, or kidney diseases.

• Dinoprostone gel or insert must not be used during fetal distress or marked cephalopelvic disproportion.

• It must be avoided in patients with a history of major uterine surgery, previous cesarean section, or if the prolonged contractions can pose a risk to the fetus or uterine integrity.

What Are the Side Effects of Dinoprostone?

Side effects of Dinoprostone are not common, and the healthcare provider must be informed immediately if any of these symptoms occur:

• Nausea and vomiting.

• Diarrhea.

• Stomach upset.

• Headache.

• Dizziness.

• Skin rashes.

• Fever.

• Chills and shivering.

• Difficulty breathing.

• Chest tightness.

• Swelling of the face.

• Increase in vaginal bleeding.

Conclusion

Dinoprostone is an FDA-approved drug used for inducing labor or evacuation of uterine contents during the management of missed abortion. This medication is available in the form of gel, insert, and suppository. It must be administered at proper dosages only by healthcare professionals. A constant close monitoring of the patient is required during the procedure to keep track of the patient’s progress. Good communication between the healthcare team and the patient will be helpful in understanding the effects of the drug and its expected outcome.