Misoprostol Dosage

Usual Adult Dose for NSAID-Induced Ulcer Prophylaxis

200 mcg orally 4 times a day after meals and at bedtime.

Usual Adult Dose for Gastric Ulcer

200 mcg orally 4 times a day after meals and at bedtime.

Usual Adult Dose for Duodenal Ulcer

200 mcg orally 4 times a day after meals and at bedtime. Alternatively, 400 mcg orally 2 times a day may be used.

Usual Adult Dose for Labor Induction

25 mcg vaginally every 4 to 6 hours.

Usual Adult Dose for Postpartum Bleeding

Prophylaxis: 400 to 600 mcg orally or rectally after delivery of the baby, but before delivery of the placenta.

Usual Adult Dose for Cervical Ripening

Before surgical abortion: 400 mcg vaginally, 3 to 4 hours before suction curettage.

Usual Adult Dose for Abortion

First Trimester of Pregnancy: 400 mcg orally once as a single dose 48 hours after mifepristone administration. Alternatively, 800 mcg vaginally 48 hours after mifepristone administration. When used with methotrexate, 5 to 7 days later give 800 mcg vaginally (misoprostol dose may be repeated 24 hours later if needed).

In Failed Pregnancy or Fetal Death: 800 mcg vaginally once or twice (doses given 24 hours apart).

Second Trimester of Pregnancy: 600 mcg vaginally, 36 to 48 hours after mifepristone administration, followed by 400 mcg orally or vaginally every 3 hours to a maximum of 5 doses in the first 24 hours.

Third Trimester of Pregnancy - Fetal Death: 100 mcg vaginally every 12 hours.

Usual Adult Dose for Gynecologic Surgery

Study (n=204) - Operative hysteroscopy: 400 mcg orally 12 to 24 hours before surgery.

Usual Pediatric Dose for NSAID-Induced Ulcer Prophylaxis

Study (n=25)
>7 years: 9.8 mcg/kg/day, given in two equally divided doses daily, to a maximum of 800 mcg/day.

Dose Adjustments

The dose may be reduced to 100 mcg orally 4 times a day or 200 mcg orally 2 times a day if the patient is unable to tolerate the recommended regimen or if the patient is maintained on chronic hemodialysis.

50 mcg every 6 hours may be appropriate for cervical ripening or labor induction in the third trimester in some situations, although higher doses appear to be associated with uterine tachysystole and possibly with uterine hyperstimulation and meconium staining of amniotic fluid.

Misoprostol should not be administered more frequently than every 3 to 6 hours.

Precautions

Misoprostol is not recommended for the treatment of inevitable or incomplete abortion.

Misoprostol possesses abortifacient properties and is considered contraindicated for use in pregnant women unless being used as single dose therapy following mifepristone administration for termination of early pregnancy

Uterine rupture has been reported with the use of misoprostol in patients with the following risk factors: later trimester pregnancies, use of high doses of the drug, prior cesarean delivery or uterine surgery, and having had five or more previous pregnancies.

Misoprostol should only be used in a woman of childbearing potential, who requires NSAID therapy and is at high risk for the development of gastric ulcers, if pregnancy has been ruled out by a negative serum pregnancy test within 2 weeks of starting misoprostol, if she is capable of complying with effective methods of birth control, and if she has been apprised of the risk should she become pregnant. Both written and oral warnings should be provided. In addition, the patient should be instructed that she must never share this drug with other individuals. Therapy should begin on the second or third day of the next normal period.

The American College of Obstetricians and Gynecologists in its position statement, related to the use of prostaglandins for the induction of labor for vaginal birth after cesarian delivery, discourages the use of misoprostol in patients with a previous cesarian or a major uterine surgery due to the increased risk of uterine rupture.

Monitoring of fetal heart rate and uterine activity should be performed on all patients undergoing cervical ripening or labor induction with misoprostol for labor induction.

The use of higher doses of misoprostol for cervical ripening or labor induction in the third trimester (50 mcg every 6 hours) appears to be associated with uterine tachysystole and possibly with uterine hyperstimulation and meconium staining of amniotic fluid.

Dialysis

In patients maintained on prolonged hemodialysis, start patient at the lower dose.

It is not known if misoprostol is dialyzable. However, because misoprostol is metabolized like a fatty acid, it is unlikely that dialysis would be appropriate treatment for overdosage.

Other Comments

Misoprostol is not considered a first-line agent for the treatment of duodenal ulcers, or gastric ulcers. There is no evidence that misoprostol is more efficacious than H2-antagonists in these settings.

Misoprostol can cause miscarriage, often associated with potentially dangerous bleeding. This may result in hospitalization, surgery, infertility or death. Do not take misoprostol if pregnant and do not become pregnant while on this medication. If pregnancy occurs during misoprostol therapy, discontinue the drug and contact physician immediately.

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