Misoprostol is indicated for:

• Prophylaxis of gastric and duodenal ulceration in NSAID users at high risk of complications from gastric ulcer e.g. the elderly, patients with concomitant debilitating disease and patients with a history of ulcer.
• Healing of established NSAID-induced gastric and duodenal damage.
• Healing of gastric and duodenal ulcers in the absence of NSAID therapy.
• Induction of labor.
• Prevention and treatment of postpartum hemorrhage.

Misoprostol is extensively absorbed and rapidly converted (de-esterified) to its active free acid form, which is responsible for its clinical effects. The parent compound is not detectable in plasma, but the active metabolite is measurable. Peak plasma levels of Misoprostol acid are reduced when taken with food, and overall bioavailability is decreased when used with antacids. Misoprostol has antisecretory effects (inhibits gastric acid secretion) and, in animal studies, mucosal protective properties. NSAIDs inhibit prostaglandin synthesis, and reduced prostaglandins in the gastric mucosa may decrease bicarbonate and mucus secretion, contributing to mucosal injury. Misoprostol increases bicarbonate and mucus production; however, in humans this effect occurs at doses of 200 mcg or higher, which are also antisecretory. Therefore, it is not clearly known whether its ulcer-preventive effect is due to antisecretory action, mucosal protection, or both.

Benign gastric and duodenal ulceration and NSAID associated ulceration: 800 mcg daily (in 2–4 divided doses) with breakfast or main meals and at bedtime; treatment should be continued for at least 4 weeks and may be continued for up to 8 weeks if required.

Prophylaxis of NSAID-induced gastric and duodenal ulcer: 200 mcg 2–4 times daily taken with NSAID. If this dose cannot be tolerated, a dose of 100 mcg can be used. Misoprostol should be taken for the duration of NSAID therapy as prescribed by the physician.

Induction of labor: Place 25 mcg in the posterior fornix of the vagina. Repeat after every 6 hours if necessary until the maximum dosage of 200 mcg total misoprostol is reached. Fetal heart rate and uterus contractions should be monitored. Alternatively, 100 mcg taken orally. If cervical ripening or active labor does not occur, repeated dose of 100–200 mcg of oral misoprostol is given every 4 hourly until labor is established (as evidenced by a Bishop score of 7 or more). Maximum number of dose is 6. Maternal vital signs, fetal heart rate and contractions should be monitored. Oxytocin can be started 4 hours after last dose of misoprostol. Physician should be notified for signs of fetal distress or tetanic uterine contractions. Oral misoprostol therapy should be monitored by physician.

Prevention of postpartum hemorrhage: 600 mcg orally immediately following delivery.

Treatment of postpartum hemorrhage: 600 mcg orally or 1000 mcg per rectally.

There is no evidence of clinically significant interaction between Misoprostol and cardiac, pulmonary, CNS drugs, or NSAIDs. The bioavailability of Misoprostol is reduced when taken with high doses of antacids.

Misoprostol is contraindicated in patients with a history of hypersensitivity to prostaglandins. It is also contraindicated during pregnancy.

Generally, Misoprostol is well tolerated. The most common adverse effects involve the gastrointestinal system, including diarrhea, abdominal pain, dyspepsia, flatulence, nausea, vomiting, rash, and dizziness. The incidence of diarrhea can be reduced by taking the drug after meals and at bedtime and by avoiding concurrent use with magnesium-containing or laxative antacids.

Due to its abortifacient effect, Misoprostol is contraindicated in pregnancy. It should not be used in women of childbearing potential unless NSAID therapy is required and there is a high risk of gastric or duodenal ulcer or related complications. In such cases, it may be used only if:

• A negative serum pregnancy test within 2 weeks prior to therapy is confirmed.
• Effective contraception is used.
• The patient is informed about risks, contraceptive failure, and danger of accidental exposure to others.
• Therapy is started only on the second or third day of the next normal menstrual period.

Excretion of Misoprostol acid into breast milk is possible but not well studied. Because of potential serious adverse effects in nursing infants, its use is not recommended during breastfeeding.

For NSAID-induced gastric and duodenal ulcer prevention and treatment: Misoprostol is contraindicated in pregnancy and should not be used in women of childbearing potential unless NSAID therapy is necessary. Women must not be pregnant before starting therapy and should use effective contraception during treatment.

For induction of labor: Pregnancy should be ≥38 weeks by reliable dating, or fetal lung maturity confirmed, or ≥36 weeks with medical indication. Induction is contraindicated in acute fetal distress, placental abruption, placenta previa, or unexplained vaginal bleeding. The fetus should be in vertex presentation.

Use in children: Safety and effectiveness of Misoprostol in children below 18 years have not been established.

The toxic dose of Misoprostol in humans is not established. Possible signs of overdose include sedation, tremor, convulsions, dyspnea, abdominal pain, diarrhea, and fever. Treatment is supportive and symptomatic.

Drugs acting on the uterus, Prostaglandin analogues

Store in a cool, dry place, protected from light and moisture. Keep out of reach of children.