Misoprostol (Page 2 of 4)

Other pharmacologic effects

Misoprostol does not produce clinically significant effects on serum levels of prolactin, gonadotropins, thyroid-stimulating hormone, growth hormone, thyroxine, cortisol, gastrointestinal hormones (somatostatin, gastrin, vasoactive intestinal polypeptide, and motilin), creatinine, or uric acid. Gastric emptying, immunologic competence, platelet aggregation, pulmonary function, or the cardiovascular system are not modified by recommended doses of misoprostol.

Clinical studies

In a series of small short-term (about 1 week) placebo-controlled studies in healthy human volunteers, doses of misoprostol were evaluated for their ability to reduce the risk of NSAID-induced mucosal injury. Studies of 200 mcg q.i.d. of misoprostol with tolmetin and naproxen, and of 100 and 200 mcg q.i.d. with ibuprofen, all showed reduction of the rate of significant endoscopic injury from about 70–75% on placebo to 10–30% on misoprostol. Doses of 25–200 mcg q.i.d. reduced aspirin-induced mucosal injury and bleeding.

Reducing the risk of gastric ulcers caused by nonsteroidal anti-inflammatory drugs (NSAIDs)

Two 12-week, randomized, double-blind trials in osteoarthritic patients who had gastrointestinal symptoms but no ulcer on endoscopy while taking an NSAID compared the ability of 200 mcg of misoprostol, 100 mcg of misoprostol, and placebo to reduce the risk of gastric ulcer (GU) formation. Patients were approximately equally divided between ibuprofen, piroxicam, and naproxen, and continued this treatment throughout the 12 weeks. The 200-mcg dose caused a marked, statistically significant reduction in gastric ulcers in both studies. The lower dose was somewhat less effective, with a significant result in only one of the studies.

Reduction of Risk of Gastric Ulcers Induced by Ibuprofen, Piroxicam, or Naproxen [No. of patients with ulcer(s) (%)]
Therapy Duration
Therapy 4 weeks 8 weeks 12 weeks
Statistically significantly different from placebo at the 5% level.
Combined data from Study No. 1 and Study No. 2.
Study No. 1
200 mcg
q.i.d. (n=74)
1 (1.4) 0 0 1 (1.4)*
100 mcg
q.i.d. (n=77)
3 (3.9) 1 (1.3) 1 (1.3) 5 (6.5)*
Placebo (n=76) 11 (14.5) 4 (5.3) 4 (5.3) 19 (25.0)
Study No. 2
200 mcg
q.i.d. (n=65)
1 (1.5) 1 (1.5) 0 2 (3.1)*
100 mcg
q.i.d. (n=66)
2 (3.0) 2 (3.0) 1 (1.5) 5 (7.6)
Placebo (n=62) 6 (9.7) 2 (3.2) 3 (4.8) 11 (17.7)
Studies No. 1 & No. 2
200 mcg
q.i.d. (n=139)
2 (1.4) 1 (0.7) 0 3 (2.2)*
100 mcg
q.i.d. (n=143)
5 (3.5) 3 (2.1) 2 (1.4) 10 (7.0)*
Placebo (n=138) 17 (12.3) 6 (4.3) 7 (5.1) 30 (21.7)

In these trials there were no significant differences between misoprostol and placebo in relief of day or night abdominal pain. No effect of misoprostol in reducing the risk of duodenal ulcers was demonstrated, but relatively few duodenal lesions were seen.

In another clinical trial, 239 patients receiving aspirin 650–1300 mg q.i.d. for rheumatoid arthritis who had endoscopic evidence of duodenal and/or gastric inflammation were randomized to misoprostol 200 mcg q.i.d. or placebo for 8 weeks while continuing to receive aspirin. The study evaluated the possible interference of misoprostol on the efficacy of aspirin in these patients with rheumatoid arthritis by analyzing joint tenderness, joint swelling, physician’s clinical assessment, patient’s assessment, change in ARA classification, change in handgrip strength, change in duration of morning stiffness, patient’s assessment of pain at rest, movement, interference with daily activity, and ESR. Misoprostol did not interfere with the efficacy of aspirin in these patients with rheumatoid arthritis.

Misoprostol Indications and Usage

Misoprostol is indicated for reducing the risk of NSAID (nonsteroidal anti-inflammatory drugs, including aspirin)–induced gastric ulcers in patients at high risk of complications from gastric ulcer, e.g., the elderly and patients with concomitant debilitating disease, as well as patients at high risk of developing gastric ulceration, such as patients with a history of ulcer. Misoprostol has not been shown to reduce the risk of duodenal ulcers in patients taking NSAIDs. Misoprostol should be taken for the duration of NSAID therapy. Misoprostol has been shown to reduce the risk of gastric ulcers in controlled studies of 3 months’ duration. It had no effect, compared to placebo, on gastrointestinal pain or discomfort associated with NSAID use.


See boxed WARNINGS.

Misoprostol should not be taken by pregnant women to reduce the risk of ulcers induced by nonsteroidal anti-inflammatory drugs (NSAIDs).

Misoprostol should not be taken by anyone with a history of allergy to prostaglandins.


See boxed WARNINGS.

For hospital use only if misoprostol were to be used for cervical ripening, induction of labor, or for the treatment of serious post-partum hemorrhage, which are outside of the approved indication.


Caution should be employed when administering misoprostol to patients with pre-existing cardiovascular disease.

Information for patients

Women of childbearing potential using misoprostol to decrease the risk of NSAID-induced ulcers should be told that they must not be pregnant when misoprostol therapy is initiated, and that they must use an effective contraception method while taking misoprostol.

See boxed WARNINGS.

Misoprostol is intended for administration along with nonsteroidal anti-inflammatory drugs (NSAIDs), including aspirin, to decrease the chance of developing an NSAID-induced gastric ulcer.

Misoprostol should be taken only according to the directions given by a physician.

If the patient has questions about or problems with misoprostol, the physician should be contacted promptly.

THE PATIENT SHOULD NOT GIVE MISOPROSTOL TO ANYONE ELSE. Misoprostol has been prescribed for the patient’s specific condition, may not be the correct treatment for another person, and may be dangerous to the other person if she were to become pregnant.

The misoprostol package the patient receives from the pharmacist will include a leaflet containing patient information. The patient should read the leaflet before taking misoprostol and each time the prescription is renewed because the leaflet may have been revised.

Keep misoprostol out of the reach of children.

SPECIAL NOTE FOR WOMEN: Misoprostol may cause birth defects, abortion (sometimes incomplete), or premature labor if given to pregnant women.

Misoprostol is available only as a unit-of-use package that includes a leaflet containing patient information. See Patient Information at the end of this labeling.

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