MisoprostolRx

Trade Names: Cytotec, Arthrotec (misoprostol + diclofenac)

Synonyms: Synthetic prostaglandin E1

Drug Class: Synthetic prostaglandin, protects against NSAID gastropathy

Preparations: 100- and 200- mcg tablets

Dose: Prophylaxis of NSAID-induced gastropathy 100–200 mcg four times daily. Efficacy best demonstrated for 200 mcg four times daily, but lower doses (200 mcg b.i.d. or 100 mcg four times daily) are better tolerated and may be nearly as effective.

Indications: Prevention of NSAID-induced gastropathy (see Comments)

Mechanism of Action: Substitutes for endogenous prostaglandins (necessary to stimulate gastric mucous and bicarbonate secretion) whose synthesis is inhibited by NSAIDs

Contraindications: Hypersensitivity to misoprostol, pregnancy

Precautions: Safety in children is not established. Ensure that women are not pregnant before starting treatment, and ensure reliable contraception while receiving misoprostol.

Pregnancy Risk: X (abortifacient and teratogenic)

Adverse Effects
Common: Diarrhea, abdominal cramps
Less common: Headaches, vaginal bleeding, miscarriage

Patient Instructions: Do not consider becoming or become pregnant while on misoprostol. Need reliable contraception May cause diarrhea. Take with food. Do  not give drug to others.

Comments: Misoprostol reduces serious GI complications caused by NSAIDs by 40%. Strategies to reduce risk should be considered in patients at high risk of NSAID-induced GI complications (those with previous GI bleeding or previous peptic ulcer, the elderly, those on combination NSAID and corticosteroid therapy) if therapy with an NSAID is necessary. Proton pump inhibitors are better tolerated. Prophylaxis in unselected NSAID users is not cost-effective. Misoprostol does not prevent GI pain (indigestion, dyspepsia) associated with NSAID use.

Clinical Pharmacology: Rapidly absorbed and metabolized to the free acid. Plasma concentrations are highest within 30 minutes of dosing. Half-life is 20–40 minutes.

Cost: $$$

BIBLIOGRAPHY

Graham DY, Agrawal NM, Campbell DR, et al. Ulcer prevention in long-term users of nonsteroidal anti-inflammatory drugs: results of a double-blind, randomized, multicenter, active- and placebo-controlled study of misoprostol vs lansoprazole. Arch Intern Med 2002;162:169-75. PMID: 11802750.