Misoprostol

Misoprostol is a prescription drug used to prevent stomach ulcers in people taking NSAIDs (nonsteroidal anti-inflammatory drugs, such as aspirin). Misoprostol belongs to a family of anti-ulcer drugs called prostaglandin E1 analogs. Another member of this family is rioprostil. The U.S Food and Drug Administration approved misoprostol in December 1988. Misoprostol is marketed as Cytotec by Pfizer.

Uses

• Misoprostol is specifically indicated to reduce the risk of gastric (stomach) ulcers in patients at high risk of complications from gastric ulcer due to use of NSAIDs (nonsteroidal anti-inflammatory drugs, such as aspirin).

• Cytotec also is used to help dilate the cervix (opening of the uterus or womb) in women prior to uterine surgery, such hysteroscopy or D&C.

• Additionally, it is commonly used to help induction of labor in pregnancy. However, it is important that a pregnant woman not receive misoprostol earlier in pregnancy as this could cause the cervix to dilate too early leading to a miscarriage.

How Misoprostol is Taken

• For gastric (stomach) ulcers, the recommended dose of misoprostol for adults is 200μg (micrograms) four times daily with food. If this dose cannot be tolerated, a lower dose of 100μg can be used.

• For gynecologic surgery or for labor induction, obstetrician/gynecologists have their patients take misoprotol tablets either by mouth or by direct application of the tablets to the cervix by placing the tablets in the vagina.

How Misoprostol Works

Misoprostol inhibits stomach acid secretion, including increased acid secretion in response to meals and coffee. This acid-reducing activity is present for 30 minutes after oral administration and persists for at least 3 hours.

In addition, since the drug is a prostaglandin analog, misoprostol has effects on the reproductive system, dilating the cervix and producing uterine contractions.

How the Body Affects Misoprostol

Misoprostol is rapidly absorbed with peak circulating levels reached at 12 minutes post-dosing.

About 80% of the original dose is excreted in the urine.

Side Effects

The most common side effects (occurring >1% of treated patients) are:

• nausea
• flatulence
• headache
• dyspepsia (indigestion)
• vomiting
• constipation

Risks and Precautions

In pregnant women, misoprostol causes uterine contractions that could result in miscarriage if taken early in the pregnancy.

Drug Interactions

Studies show misoprostol does NOT exert significant effects on the circulating levels or antiplatelet effects of aspirin.

Research

Two trials compared 200μg misoprostol and placebo in reducing the risk of stomach ulcer formation in ulcer-free patients taking NSAIDs.^[1]

Cytotec produced a significant reduction in stomach ulcers in both studies.

References

1. ↑ Food and Drud Administration Web site. Cytotec (misoprostol) PDF

External Links

FDA: Patient Information Sheet