Maintenance therapy with sucralfate reduces rate of gastric ulcer recurrence

What are the current possibilities in treating peptic ulcer disease?

There are two major principles of ulcer therapy. Today, the most widely accepted drugs are those which substantially reduce aggressive factors (i.c. acid and pepsin), namely histamine H2-receptor antagonists, antimuscarinics and antacids. Less frequently applied are mucoprotective agents like colloidal bismuth compounds and sucralfate. Prostaglandins both reduce acid secretion substantially and are believed to enhance mucosal resistance. Their anti-ulcer efficacy, however, is solely explicable by their antisecretory activity. Although mucosa-strengthening agents and H2-receptor blockers have nearly identical healing rates, mucosa-strengthening agents have inconvenient dosage regimens (four times or twice daily) and are probably less effective in relieving pain. The same holds true for antacids. Prostaglandins, antimuscarinics and antacids have dose related side effects. In contrast, H2-receptor blockers are characterized by a clear mechanism of action, convenient dosage regimens, good tolerance and a low incidence of side-effects. H2-receptor antagonists are the most effective anti-ulcer drugs presently available.

Review article: maintenance treatment with H2-receptor antagonists for peptic ulcer disease

In recent years a number of different strategies for managing patients with peptic ulcer disease have become available. The present review discusses the relative merits of each form of treatment. Intermittent treatment (whether given in response to symptoms or as a prophylactic regimen prescribed seasonally or at weekends) fails to prevent ulcer recurrence and leaves patients at risk of haemorrhage and perforation. Anti-Helicobacter pylori therapy, although useful in certain circumstances, cannot be recommended for all patients with ulcer disease because of side effects and, in any case, requires further assessment of efficacy. Gastric surgery reduces ulcer recurrence and complications, but operations which have a low incidence of side effects are associated with higher rates of ulcer recurrence, particularly when patients are followed up for more than 10 years. Long-term continuous maintenance treatment with H2-receptor antagonists for 5 or more years effectively prevents ulcer recurrence in the majority of patients and significantly reduces the risk of ulcer complications. In addition, maintenance treatment has proved to be safe and is well tolerated by patients. Maintenance treatment with H2-receptor antagonists is the preferred option for the management of patients with peptic ulcer disease.

Nocturnal therapy with famotidine for 1 year is effective in preventing relapse of gastric ulcer

A multicentre, double-blind, randomized, placebo-controlled trial was undertaken to investigate the therapeutic efficacy of a nocturnal dose of famotidine 20 mg to reduce the 1 year relapse rate of recently healed gastric ulcers. Twenty investigators in eight countries randomized 202 patients with endoscopically confirmed healed gastric ulcers. Repeat endoscopies were performed at 6 and 12 months or for symptoms compatible with ulcer relapse. A per protocol analysis of cumulative life table relapse at 12 months showed that famotidine 20 mg was superior to placebo in reducing gastric ulcer relapse, 24 versus 50%, respectively (P less than 0.01). Both placebo and famotidine were well tolerated. Since nocturnal dosing with famotidine 20 mg is effective in preventing gastric ulcer relapse over a 1-year period and is well tolerated, it offers a therapeutic option for the long-term treatment of patients with gastric ulcer.

The mode of action of sucralfate: the 1 x 1 x 1 mechanism of action

Of the multiple actions of sucralfate, not all are equally relevant. In fact, certain actions of the drug contribute to healing of acute ulcers or to ulcer prevention, whereas other actions are more important in accelerating the healing of gastric and duodenal ulcers. The action of sucralfate can now be defined by the '1 x 1 x 1' mechanism of action--that is, one action of sucralfate is important for acute prevention, one is relevant to both acute and chronic protection, and one is important for chronic ulcer healing. Maintenance of mucosal vascular integrity and of blood flow, which ensures rapid epithelial restitution to repair superficial defects, are the most important acute actions of sucralfate. On the other hand, increased bicarbonate and mucus secretion seem to be relevant in both acute and chronic protection of the gastroduodenal mucosa. Finally, the enhanced binding by sucralfate of fibroblast growth factor and epidermal growth factor stimulates angiogenesis, granulation tissue, and epithelization for ulcer healing. This 1 x 1 x 1 theory of the mechanism of action of sucralfate concentrates on the relevant effects of this drug (which has more than a dozen actions) and may help to elucidate the molecular mechanism of action.

Sucralfate in the treatment and prevention of gastric ulcer: multicentre double blind placebo controlled study

A randomised controlled multicentre trial was performed in 160 patients with gastric ulcer, proved by endoscopy and biopsy, to compare ulcer healing with sucralfate and ranitidine (double blind double dummy design) and to assess the effect of maintenance treatment with sucralfate on ulcer recurrence (double blind placebo controlled design). The healing rates were similar with 4 g sucralfate suspension per day and 300 mg ranitidine per day (82% and 88% after 12 weeks, respectively). Of the 109 patients with healed ulcers, 92 were entered into the maintenance trial and treated with sucralfate tablets (2 g per day) or placebo tablets. Maintenance treatment with sucralfate delayed symptoms of gastric ulcer recurrence. Lifetable analysis showed significant differences between sucralfate and placebo, both after six months (p = 0.018) and after 12 months (p = 0.044). The rates of symptom recurrences were 13% and 34% after six months and 34% and 55% after 12 months for sucralfate and placebo, respectively. The rate of asymptomatic recurrences after 12 months was similar in the two groups (9% and 10%, respectively). The recurrence rate was higher in patients who had never taken non-steroidal anti-inflammatory drugs than in those who had but had stopped on admission to the study. It was also higher in patients with recurrent ulcer and in those with scarring deformation and narrowing of the pylorus. Maintenance treatment with sucralfate slowed the appearance of symptom recurrences of gastric ulcer.

Protection of rat gastric mucosa by sucralfate. Effects of luminal stasis and of inhibition of prostaglandins synthesis

Studies using a gastric chamber model demonstrated that sucralfate protected the rat gastric mucosa against hemorrhagic erosions induced by 40 percent ethanol and by acidified 80 mM sodium taurocholate. Protection required continuous contact of sucralfate with the gastric mucosa but it occurred without the production, by sucralfate alone, of significant damage to the luminal epithelium. Ultrastructural examination indicated that sucralfate stimulated mucus secretion by surface epithelial cells. Furthermore, sucralfate was "cytoprotective" in that, in addition to its anti-ulcer effects, it significantly reduced the damaging effects of luminal ethanol on the surface epithelium. Luminal stasis also significantly reduced the extent of hemorrhagic erosions produced by both ethanol and sodium taurocholate, but the most effective reduction in erosions occurred when sucralfate and luminal stasis were combined. Pretreatment with indomethacin abolished the protection provided by luminal stasis, but this protection was restored by sucralfate. Thus, these studies suggest that protection of the gastric mucosa by sucralfate results in part from effects on the unstirred layer. Sucralfate or its products also interact with the epithelial cells and stimulate mucus release and synthesis or release of inflammatory mediators.

Nocturnal dosage regimen of sucralfate in maintenance treatment of gastric ulcer

Sixty-six patients with recently healed gastric ulcers were entered into a double-blind, placebo-controlled, six-month maintenance trial to determine whether sucralfate 2 g at night reduces the liability to recurrent ulceration. Thirty-three patients were randomly assigned to treatment with sucralfate and 33 were assigned to placebo. Endoscopy was performed at the time of entry into the study and at 24 weeks, or earlier if clinical relapse occurred during this period. Of the patients available for analysis, endoscopic recurrences were found in eight of the 29 patients (28 percent) randomly assigned to sucralfate and in 15 of the 27 patients (56 percent) assigned to placebo. Eight of the recurrences noted at 24 weeks were asymptomatic and, of these, five were in the placebo-treated group. The cumulative relapse rate at 24 weeks was significantly lower in the sucralfate-treated group (p less than 0.05), and the Cox-Mantel text showed a significant difference between the cumulative relapse curves of the two treatment groups over the 24-week period (p less than 0.05). The results indicate that a single maintenance dose of sucralfate 2 g at night reduces the relapse rate in patients with recently healed gastric ulceration.

Maintenance therapy for prevention of recurrent peptic ulcers

Peptic ulcer disease is a chronic, relapsing disease. Successful healing of duodenal and gastric ulcers with antacids, cimetidine, ranitidine, famotidine, or sucralfate is frequently followed by ulcer recurrence. The need for long-term, low-dose maintenance therapy is based on disease severity, ulcer history, complications, therapeutic intervention, response to treatment, and potential risk factors. Comparison of ulcer maintenance trials requires consideration of important factors such as frequency of endoscopy, duration of follow-up period, and the method used to calculate ulcer recurrence rates. Clinical trials indicate that chronic treatment with low-dose cimetidine, ranitidine, famotidine, and probably sucralfate decreases the frequency of duodenal ulcer recurrence and that ranitidine may be superior to cimetidine. Preliminary studies indicate that higher doses of these same medications may be required to prevent gastric ulcer recurrence. Long-term maintenance therapy with these agents must be continuous in order to prevent relapses, but treatment should be limited to one year because of unknown consequences beyond this period.

Elevation of serum aluminum in humans on a two-day sucralfate regimen

Serum aluminum concentrations were determined in ten healthy subjects treated with phenytoin 500 mg and with sucralfate and phenytoin in a crossover fashion. Each subject received four 1,000-mg sucralfate tablets between 8 AM and 10 PM one day before the study, and this was repeated during the study day. A total of eight doses of sucralfate was administered over the two-day period. Serum samples were drawn at 0, 2, 4, 8, 12, 24, 32, and 48 hours after administration. The areas under the serum aluminum concentration-time curves before and after sucralfate (mean +/- SD) were 496.0 +/- 80.9 and 770.9 +/- 146.6 hr-ng/mL, respectively. This increase is statistically significant (P less than .01), indicating that serum aluminum levels are elevated even after two days of treatment with sucralfate. The results from this study are not in agreement with the only other report on this subject.

Gastric protection by sucralfate. Role of mucus and prostaglandins

Sucralfate promotes the healing of peptic ulcers and, in large doses, increases gastric mucosal prostaglandins. The present study was designed to further elucidate the protective effect of sucralfate and to evaluate the role of prostaglandins in this action. Eight chair-adapted rhesus monkeys received a subcutaneous injection of either 150 mg/kg of aspirin or vehicle in combination with either a therapeutic oral dose of sucralfate (50 mg/kg X day) or water. Gastric soluble mucus concentration was determined in samples of gastric juice by Alcian blue dye binding of acidic glycoproteins, and mucus output was determined using a technetium 99m-diethylenetriaminepentaacetic acid dilution technique. Monkeys underwent endoscopy to assess gastric mucosal damage, which was ranked blindly on a scale of 0-5, and to obtain biopsy specimens for determination of mucosal prostaglandin E2, prostaglandin F2 alpha, and 6-keto-prostaglandin F1 alpha. Aspirin did not alter soluble mucus but did significantly increase gastric mucosal damage and suppress tissue levels of all prostaglandins. Sucralfate significantly increased the output of soluble mucus, even after aspirin treatment, and protected against aspirin-induced damage, although it did not modify aspirin-induced suppression of prostaglandins. These results suggest that the gastric protection afforded by sucralfate is related to a prostaglandin-independent increase in mucus production.

Protective drugs in the treatment of gastroduodenal ulcer disease

Reduction of gastric acidity by the inhibition of secretion or neutralization is the therapeutic principle most widely used in peptic ulcer disease. From a pathophysiological standpoint, this does not appear logical, because in a majority of patients gastric acid secretion is not increased. In addition, there is some concern about the consequences of a reduction in gastric acidity, especially in the long term. And finally, all available inhibitors of gastric acid secretion have a systemic action and may thus cause systemic side effects. Carbenoxolone, sucralfate, and tri-potassium dicitrato bismuthate have been shown to accelerate healing of ulcers without appreciable acid inhibition. Despite an apparently different mode of action, the healing rates are similar to those of commonly used acid inhibitors. Several possible mechanisms of action have been claimed for each of these agents, but none has been convincingly demonstrated to be essential in ulcer healing. This may reflect ignorance of the relevant events rather than an action by a combined principle.