What is the use of misoprostol (prostaglandin E1 analogue)?

From the Guidelines

Misoprostol is primarily used for preventing and treating stomach ulcers, particularly in patients taking nonsteroidal anti-inflammatory drugs (NSAIDs), as well as for obstetric purposes such as labor induction, medical abortion, and managing postpartum bleeding. The medication is often prescribed at a dose of 200 mcg four times daily with meals and at bedtime for stomach ulcer prevention, especially in high-risk patients taking NSAIDs 1. In obstetrics, misoprostol is used at various doses, including 25-50 mcg vaginally every 4-6 hours for labor induction, 800 mcg vaginally or sublingually for medical abortion (often combined with mifepristone), and 600-800 mcg sublingually or rectally for postpartum hemorrhage.

Key Points

• Misoprostol works by mimicking prostaglandin E1, which protects the stomach lining by reducing acid secretion and increasing protective mucus, while in obstetrics it causes uterine contractions and cervical softening 1.
• Common side effects of misoprostol include diarrhea, abdominal pain, and nausea, with doses of at least 600 mg/day causing these adverse effects in approximately 20% of patients, leading to frequent discontinuation 1.
• Misoprostol is contraindicated during pregnancy when used for ulcer prevention due to its ability to cause miscarriage and should be used cautiously in patients with certain cardiovascular conditions.

Uses and Dosage

• For stomach ulcers, misoprostol has been shown to reduce NSAID-associated GI complications by 40% and significantly reduces gastroduodenal ulcers, with a meta-analysis indicating a 74% decrease in endoscopic gastric ulcers and a 53% decrease in duodenal ulcers compared to placebo 1.
• The effectiveness of misoprostol over standard and double doses of proton pump inhibitors (PPIs) has been confirmed in a study among H. pylori-negative chronic NSAID users who had a history of gastric ulcer, with misoprostol proving superior 1.

From the FDA Drug Label

Misoprostol tablets are 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 is used for reducing the risk of NSAID-induced gastric ulcers in high-risk patients, such as the elderly and those with debilitating diseases or a history of ulcers 2.
• It should be taken for the duration of NSAID therapy.
• Key uses include:
  • Reducing the risk of gastric ulcers in patients taking NSAIDs
  • Protecting high-risk patients, such as the elderly and those with concomitant debilitating disease

From the Research

Uses of Misoprostol

• Misoprostol is used to prevent gastric and duodenal ulcers associated with long-term nonsteroidal anti-inflammatory drug (NSAID) therapy 3.
• It is effective in healing both gastric and duodenal ulcers, with a success rate of 60 to 85% for duodenal ulcers and 32 to 54% for gastric ulcers 4.
• Misoprostol has been shown to be effective in preventing NSAID-associated ulcers, with similar efficacy to H2 antagonists and sucralfate in preventing duodenal ulcers, but more effective in preventing gastric ulcers 5.
• It is also used to treat small bowel ulcers and erosions in patients taking low-dose aspirin or NSAIDs with obscure gastrointestinal bleeding, with a complete healing rate of 54% compared to 17% with placebo 6.
• Additionally, misoprostol has been investigated as a potential treatment to prevent postpartum hemorrhage, although one study found it to be ineffective and associated with more adverse effects when administered with oxytocin 7.

Dosage and Administration

• The recommended dosage of misoprostol for preventing NSAID-associated ulcers is 200 micrograms twice or three times daily 3.
• For the treatment of small bowel ulcers and erosions, the dosage is 200 micrograms four times daily for 8 weeks 6.
• Misoprostol can be administered orally, and its efficacy and safety have been established in various clinical trials 3, 4, 5, 6.

Safety and Efficacy

• Misoprostol has been shown to be well-tolerated in most patients, with common adverse events including diarrhea, abdominal pain, and nausea or vomiting 3, 4, 6.
• However, one study found that misoprostol was associated with more adverse effects, including fever and shivering, when administered with oxytocin to prevent postpartum hemorrhage 7.
• The efficacy and safety of misoprostol have been established in various clinical trials, and it is considered a useful treatment option for patients with peptic ulcer disease and those at risk of NSAID-associated ulcers 3, 4, 5, 6.