Dose-response, meal-stimulated gastric antisecretory study of prostaglandin E1 analog, misoprostol, in man

A comparison of two prostaglandin analogues (enprostil vs misoprostol) in the treatment of acute duodenal ulcer disease

We conducted a clinical trial to compare the efficacy and safety profile of two prostaglandin analogues, enprostil (35 micrograms twice daily) and misoprostol (200 micrograms four times daily) in the treatment of acute duodenal ulcers in 214 patients. The two agents healed approximately 80% and in excess of 90% of duodenal ulcers after 4 and 6 weeks' therapy, respectively. There was a significantly lower ulcer healing rate in both treatment groups in smokers compared with non-smokers (P < 0.05). However, daytime and nighttime ulcer pain relief was achieved in fewer than 50% of patients by either agent. Diarrhea, which occurred in more than 40% of patients, was the predominant side effect, and occurred mainly during the first 2 weeks of therapy with either agent. Nevertheless, this side effect was mild and self-limiting in the majority of patients. Both agents were found to be safe and well tolerated by the majority of patients. We conclude that these prostaglandin analogues are safe and effective duodenal ulcer healing agents. Furthermore, there was very little difference between enprostil and misoprostol. The limiting factors, however, for their routine use as ulcer healing agents are their low efficacy with regard to ulcer pain relief and the high incidence of diarrhea.

Helicobacter pylori infection, ABO blood group, and effect of misoprostol on gastroduodenal mucosa in NSAID-treated patients with rheumatoid arthritis

Our aim was to investigate the effect of misoprostol on NSAID-induced gastroduodenal mucosal damage in patients with rheumatoid arthritis. The study included 40 patients, and it was designed as a double-blind, placebo-controlled trial. Misoprostol significantly reduced the gastroduodenal mucosal lesions found at endoscopy (P < 0.05) and prevented the development of ulcers. The cumulative incidence of ulcers at four weeks was 5% in the placebo group and 0% in the misoprostol group. The basal and pentagastrin-stimulated acid output as evaluated after 23 days of treatment with misoprostol was not significantly affected. Forty-one percent of the patients had signs of current Helicobacter pylori infection, 33% had positive serology only, and 26% had no evidence of infection. Most of the patients with current infection belonged to blood group O (P < 0.05). Misoprostol treatment did not affect the occurrence of Helicobacter pylori or the rheumatic disease activity. It is concluded that the protective actions of misoprostol on the gastroduodenal mucosa of NSAID-treated patients are largely mediated by mechanisms other than inhibition of acid secretion. The relationship among active Helicobacter pylori infection, blood group O, and peptic ulcer may be helpful to identify a subpopulation of patients taking NSAIDs at risk of developing peptic ulcers.

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 versus antacid titration for preventing stress ulcers in postoperative surgical ICU patients

Bleeding from gastroduodenal lesions is a potentially life-threatening complication in patients subjected to overwhelming physiologic stress. Titration of gastric contents with antacid was the first prophylactic treatment regimen proved to decrease the incidence of bleeding and remains the standard by which other methods are compared. We designed a prospective double-blind, double-placebo study comparing the effectiveness of antacid titration with fixed doses of a synthetic prostaglandin E1 analog (misoprostol) for preventing stress gastritis and bleeding. To assess the success of each treatment regimen, we did endoscopic examinations before operation, 72 hours after operation, and after the patient had completed the study. A total of 281 patients entered the study (140 misoprostol, 141 antacid). The two groups were comparable with respect to preoperative parameters and type of operation. We found no statistically significant differences between the two treatment groups concerning upper gastrointestinal tract lesions or serious adverse effects. No clinically evident upper gastrointestinal hemorrhage occurred in either group. Mean gastric pH, measured at two-hour intervals during the initial 72 hours, was maintained at 4.0 or higher in both groups. We conclude that fixed-dose misoprostol is as effective as intensive antacid titration in preventing stress ulcers and bleeding in surgical ICU patients.

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.