BRAND NAMES
 MECHANISM OF ACTION
Misoprostol is an analogue of naturally occurring prostaglandin E1 which promotes peptic ulcer healing and symptomatic relief.
Misoprostol has both antisecretory (inhibiting gastric acid secretion) and mucosal protective properties. NSAIDs inhibit prostaglandin synthesis, and a deficiency of prostaglandins within the gastric mucosa may lead to diminishing bicarbonate and mucus secretion and may contribute to the mucosal damage caused by these agents.
Misoprostol can increase bicarbonate and mucus production, but in man this has been shown at doses 200 mcg and above that are also antisecretory. It is therefore not possible to tell whether the ability of misoprostol to reduce the risk of gastric ulcer is the result of its antisecretory effect, its mucosal protective effect, or both.
Misoprostol has been shown to produce uterine contractions that may endanger pregnancy.
Misoprostol is indicated for the treatment of duodenal ulcer and gastric ulcer including those induced by nonsteroidal anti-inflammatory drugs (NSAID) in arthritic patients at risk, whilst continuing their NSAID therapy.
Misoprostol can also be used for the prophylaxis of NSAID-induced ulcers.
Healing of duodenal ulcer, gastric ulcer and NSAID-induced peptic ulcer: 800 micrograms daily in two or four divided doses taken with breakfast and / or each main meal and at bedtime.
Treatment should be given initially for at least 4 weeks even if symptomatic relief has been achieved sooner. In most patients ulcers will be healed in 4 weeks but treatment may be continued for up to 8 weeks if required. If the ulcer relapses further treatment courses may be given.
Prophylaxis of NSAID-induced peptic ulcer: 200 micrograms twice daily, three times daily or four times daily. Treatment can be continued as required. Dosage should be individualised according to the clinical condition of each patient.
- Pregnancy, since it may cause miscarriage.
- Misoprostol should not be taken by anyone with a history of allergy to prostaglandins.
 PREGNANCY AND LACTATION
Pregnancy Category X (US) Misoprostol is contraindicated in pregnant women and in women planning a pregnancy as it increases uterine tone and contractions in pregnancy which may cause partial or complete expulsion of the products of conception. Use in pregnancy has been associated with birth defects. 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.
Nursing mothers: Misoprostol is rapidly metabolized in the mother to misoprostol acid, which is biologically active and is excreted in breast milk. There are no published reports of adverse effects of misoprostol in breast-feeding infants of mothers taking misoprostol. Caution should be exercised when misoprostol is administered to a nursing woman.
 SIDE EFFECTS
Diarrhoea has been reported and is occasionally severe and prolonged and may require withdrawal of the drug. It can be minimised by using single doses not exceeding 200 micrograms with food and by avoiding the use of predominantly magnesium containing antacids when an antacid is required.
Abdominal pain with or without associated dyspepsia or diarrhoea can follow misoprostol therapy.
Other gastrointestinal adverse effects reported include dyspepsia, flatulence, nausea and vomiting
Misoprostol induces uterine contraction in women; menorrhagia, vaginal bleeding and intermenstrual bleeding have been reported in pre-and post-menopausal women.
Misoprostol induces labour and abortion
 RELATED LINKS
|Heartburn/Gastritis/Gastric ulcer/Duodenal ulcer/Gastroesophageal reflux|
|H2 antagonists||Famotidine • Nizatidine • Ranitidine (Zantac)|
|Proton-pump inhibitors||Dexlansoprazole (Dexilant) • Esomeprazole (Nexium) • Lansoprazole (Prevacid) • Omeprazole (Losec, Prilosec) • Omeprazole/Sodium bicarbonate (Zegerid) • Pantoprazole (Controloc, Pantecta, Pantoloc, Protonix) ( • Rabeprazole (Aciphex, Pariet)|
|Other drugs||Alginic acid • Magaldrate • Sucralfate|
|Combination Regimens||Bismuth Subcitrate Potassium/Metronidazole/Tetracycline (Pylera) • Lansoprazole/Amoxicillin/Clarithromycin (Prevpac)|