Misoprostol

 Action Synthetic prostaglandin E1 analog that inhibits gastric acid secretion and exerts mucosal-protective properties.

 Indications Prevention of gastric ulcers in high-risk patients who are taking nonsteroidal anti-inflammatory drugs (NSAIDs). Unlabeled use(s): Treatment of duodenal ulcers and duodenal ulcers unresponsive to H2 receptor antagonists.

 Contraindications History of allergy to prostaglandins; pregnancy.

 Route/Dosage

ADULTS: PO 100–200 mcg qid, in conjunction with NSAID therapy.

 Interactions None well documented.

 Lab Test Interferences None well documented.

 Adverse Reactions

CNS: Headache. GI: Diarrhea (dose-related, developing usually early in course of therapy and self-limiting; may require discontinuation in some patients); abdominal pain; nausea; flatulence; dyspepsia; vomiting; constipation. GI: Menstrual disorders.

 Precautions

Pregnancy: Category X. Lactation: Undetermined. Children: Safety and efficacy not established in children < 18 yr. Elderly: Reduce dosage if usual dose is not tolerated. Fertility impairment: May adversely affect fertility. Renal impairment: May reduce clearance of drug; routine dosage adjustment is not recommended unless usual dose is not tolerated. Duodenal ulcers: Not for prevention of duodenal ulcers in patients on NSAIDs. Women of childbearing potential: Contraindicated in pregnant women because of its abortifacient property. Avoid in women of childbearing potential unless patient requires NSAIDs and is at high risk of complications from gastric ulcers associated with use of NSAIDs. If used in woman of childbearing potential, patient should be capable of complying with effective contraceptive measures; have received oral and written warnings of the hazards of misoprostol, risk of possible contraception failure and danger to other women of childbearing potential should drug be taken by mistake; and have negative serum pregnancy test within 2 wk prior to starting therapy.

 Administration/Storage

• If used in woman of childbearing potential, begin therapy on second or third day of menstrual cycle.
• Administer with food and at bedtime to reduce incidence of diarrhea.
• Store in tight container in dry cool place.

 Assessment/Interventions

• Obtain patient history, including drug history and any known allergies. Note history of headaches, types of contraception, renal function.
• Monitor patient for signs and symptoms of gastric irritation and ulcers.
• Ensure that pregnancy test has been performed within 2 wk prior to initiation of therapy. Make sure that test result is negative before beginning therapy.
• If headaches, GI distress, menstrual irregularities, or signs of renal dysfunction occur, notify physician.
• Ensure that female patients of childbearing potential have received both oral and written warning regarding hazards of misoprostol in pregnancy.

 Patient/Family Education

• If patient is woman of childbearing potential, review the following: edication may adversely affect pregnancy, causing miscarriage; need for effective contraception; need to stop medication and notify physician immediately if pregnancy is suspected.
• Advise patient to take with food to reduce incidence of diarrhea.
• Instruct patient not to give this medication to anyone else.
• Inform patient not to discontinue or alter dose unless directed by physician.
• Advise patient to avoid magnesium-containing antacids because of risk of diarrhea.
• Advise patient to avoid alcohol and foods that may increase GI irritation.
• Instruct patient to notify physician if increasing or persistent headache occurs.
• Teach patient to report these symptoms to physician: diarrhea, constipation, nausea, vomiting, menstrual changes.