Double-blind comparison of two dosage regimens of misoprostol in the treatment of duodenal ulceration

Stabilization and sustained-release effect of misoprostol with methacrylate copolymer

The use of ammonio methacrylate copolymer (Eudrgit RS, RL) to form a sustained-release solid dispersion of Misoprostol can improve and enhance two important physical and chemical properties of Misoprostol. First, the solid dispersion matrix formed by the copolymer can protect Misoprostol from being degraded by water so that its stability is improved. Second, Misoprostol can be slowly released by diffusion from the copolymer matrix. Accelerated stability studies of Misoprostol-Eudragit solid dispersion after storing at various temperatures for different time periods were carried out. According to high performance liquid chromatography (HPLC) analyses, the stability of Misoprostol in a series of Eudragit appeared significantly improved at different ratios. The Misoprostol-Eudragit dispersion can be used in a powder form, filled in capsules, or compressed into tablets. The dissolution profiles of Misoprostol-Eudragit solid dispersion and its tablets in water, pH 1. 2, 4.5 and 6.8, dissolution media show that this stable solid dispersion is a sustained-release type.

Human jejunal secretion induced by prostaglandin E1: a dose-response study

1. Intraluminally infused prostaglandins induce jejunal secretion of water and electrolytes in man, and a receptor-mediated process in the intestinal epithelial cells has been suggested to explain this secretion. In an attempt to obtain data under basal conditions for pharmacological studies, we tested the dose-response effect of PGE1 on jejunal hydroelectrolytic movements in 10 healthy volunteers. 2. Accordingly, a solution with or without PGE1 was infused via a four-lumen tube with a proximal occluding balloon and jejunal water and electrolyte transport were determined. The segment tested was 40 cm long. Seven randomized doses of PGE1 ranging from 0.01 to 1.3 micrograms kg-1 min-1 (2.83 to 364 pmol kg-1 min-1) were infused in an isotonic control saline solution. The secretion induced by PGE1 was evaluated in each subject as the difference between fluxes in response to the control saline solution and to PGE1. 3. Whatever the dose, PGE1 induced secretion of water, Na+, K+ and Cl- which was dose-dependent and saturable, with a mean Km of congruent to 6-8 pmol kg-1 min-1, suggesting that at the pharmacological doses used, enterocytes have a saturable membrane site similar to a single class of receptor for PGE1. 4. These findings may be of great importance if prostaglandins are administered as drugs or used as jejunal secretory agents in vivo when the antisecretory effect of another drug is studied.

Economic evaluation of gastric ulcer prophylaxis in patients with arthritis receiving non-steroidal anti-inflammatory drugs

This study assesses the economic benefits of misoprostol in the prophylaxis of gastric ulcers larger than 0.3 cm in patients with osteoarthritis receiving non-steroidal anti-inflammatory drugs. Independent epidemiological data were obtained for patients in Scotland and the West Midlands. Co-diagnosis of arthritis with gastric ulcer recorded in the routine data was substantially less (4% Scotland, 10% West Midlands) than the 21% found at case review. These data were combined with cost and patient management data in a decision analysis model to explore whether prophylactic use of misoprostol altered substantially the average cost of managing gastric ulcer. Using conservative assumptions and a daily dose of 400 micrograms, cost savings per patient to the National Health Service of 5-8 pounds over a 3-month period are expected in the groups of patients studied, while at the 800 micrograms dose there would be a net cost of 23-25 pounds. Sensitivity analysis showed that under many assumptions misoprostol is expected to be cost saving or cost neutral.

Misoprostol: discovery, development, and clinical applications

Misoprostol is a synthetic 15-deoxy-16-hydroxy-16-methyl analog of PGE1, and the first prostaglandin to be registered for the treatment of peptic ulcer disease. Misoprostol is a safe and well-tolerated drug that exerts potent gastric antisecretory effects and mucosal protective actions on the gastric and duodenal mucosa. In a dosage of 800 micrograms daily in two or four divided doses, misoprostol produced rates of complete ulcer healing in both gastric and duodenal ulcer patients significantly superior to placebo and comparable to H2 receptor antagonists. The major adverse effect is diarrhea in about 10% of patients, but this is usually mild and self-limiting. Misoprostol possesses uterotonic activity and should not be used in pregnant women or those who wish to become pregnant. Misoprostol effectively heals and prevents NSAID-induced gastropathy, a therapeutic need previously unserved. Due to its mucosal protective properties, misoprostol may have advantages over antisecretory drugs in the compromised patient who is a chronic smoker or alcohol user, in refractory duodenal ulcer patients, in recurrent ulcer, and in emergency use for acute upper GI bleeding. Misoprostol's tissue-protective effects may also extend to other therapeutic areas.

Misoprostol: a prostaglandin E1 analog with antisecretory and cytoprotective properties

Misoprostol, a methylester analog of prostaglandin E1, with antisecretory and cytoprotective properties, has undergone extensive investigation and has received Food and Drug Administration approval for the prevention of nonsteroidal-induced ulceration. The drug represents the first synthetic, orally active prostaglandin evaluated for the treatment of peptic ulcer disease. Clinical studies reveal a trend toward slightly lower healing rates with misoprostol when compared with histamine (H2)-receptor antagonists in the treatment of gastric and duodenal ulcers. In addition, misoprostol was less effective than H2-blockers in reducing ulcer pain, and caused a higher incidence of adverse reactions, particularly diarrhea occurring in up to 13 percent of the patients treated. Several studies have shown misoprostol to be superior to cimetidine and sucralfate in the prevention of alcohol- and drug-induced gastritis. This report summarizes the biopharmaceutics, pharmacokinetics, and clinical efficacy of misoprostol in the treatment of gastric and duodenal ulcers and in the prevention of mucosal injury.