Sucralfate

Abstract

Synopsis: Sucralfate¹ is a basic aluminium salt of sulphated sucrose which is advocated for use in peptic ulcer disease. It is minimally absorbed after oral administration and is believed to act primarily at the ulcer site by protecting the ulcer from the effects of pepsin, acid and possibly bile salts. Controlled therapeutic trials have demonstrated that sucralfate 1g 4 times daily is effective in increasing the rate of healing of duodenal and gastric ulcer over a period of 4 to 8 weeks. Trials comparing sucralfate and cimetidine have not found any significant difference in efficacy between the drugs in small numbers of patients. A dosage of 2g daily given prophylactically decreases the rate of recurrence of duodenal ulcers, but the efficacy of sucralfate in preventing relapse of gastric ulcers has yet to be clearly demonstrated. Sucralfate is particularly well tolerated. Constipation, the most common side effect, occurs in 2% of patients. Thus, sucralfate offers an effective and well tolerated alternative for the management of peptic ulcer disease. Pharmacodynamic Studies: Animal studies have demonstrated a white paste-like substance that adheres selectively to ulcerated tissue after oral administration of sucralfate. The greater affinity of sucralfate for ulcer tissue than for healthy tissue has been confirmed in humans with gastric or duodenal ulcer who have undergone gastric resection or endoscopic biopsy. Sucralfate decreases pepsin activity in vivo in rats and humans, and in diffusion cell experiments sucralfate-coated albumin was protected from peptic activity for over 3 hours. In other in vitro experiments sucralfate has been shown to adsorb bile salts, to decrease acid diffusion and have acid-buffering properties. However, sucralfate is minimally antacid. Sucralfate decreases the frequency of ulcerous lesions in animals, caused by a variety of ulcerogenic substances and experimental techniques. In healthy subjects, aspirin-induced gastric mucosal damage was completely prevented in 8 of 12 subjects by prior administration of sucralfate 1g. The ability of sucralfate to limit gastric mucosal damage is also suggested by a rise in transmucosal electric potential difference following its administration in patients with gastric ulcer. Pharmacokinetic Studies: Sucralfate is minimally absorbed after oral administration, with only 0.5 to 2.2% of a dose being recovered in the urine over a 4-day period after ingestion of ¹⁴C-labelled sucralfate. In animal distribution studies, 85 to 95% of a dose was located in the gastrointestinal tract. Therapeutic Trials: Sucralfate has been compared with placebo and with cimetidine in patients with duodenal or gastric ulcer. Controlled trials have reported endoscopically confirmed healing of duodenal ulceration in 67 to 92% of patients treated with sucralfate 4g daily for 4 weeks and in 25 to 64% treated with placebo. The consumption of antacids has varied considerably between studies and may have contributed to the high placebo response rates in some studies. Comparisons of sucralfate 4g and cimetidine 1 to 1.2g daily have generally been reasonably well designed, but have usually involved too few patients to be expected to detect any possible significant difference in efficacy between the drugs. Healing rates with sucralfate and cimetidine have been 66 to 80% and 73 to 75%, respectively, at 4 weeks. Placebo-controlled studies in gastric ulcer have usually been less well designed than those in duodenal ulcer, although sucralfate 4 to 4.5g daily has been more effective than placebo in patients assessed endoscopically. In gastric, as in duodenal, ulcer, comparisons with cimetidine have included relatively small numbers of patients, and healing rates with both drugs have been similar after 6 or 8 weeks of treatment. Sucralfate 1g twice daily administered prophylactically decreases the frequency of recurrence of duodenal ulcer relative to placebo over a period of 6 months. There was a tendency for 2g daily to be more effective than 1g daily in preventing duodenal ulcer relapse, but too few patients were included in each study group to permit any firm conclusion. Preliminary studies of sucralfate in the prevention of gastric ulcer recurrence are inconclusive. Further studies with different dosages of sucralfate in adequate numbers of patients are necessary to establish the efficacy of the drug in preventing recurrence of gastric ulcer and to determine the optimum dosage. Side Effects: Few side effects are associated with administration of sucralfate 4g daily in the treatment of duodenal or gastric ulcer. Constipation is the most frequently reported complaint, which occurs in about 2% of patients. As sucralfate is a phosphate binder in patients with uraemia, it has potential to induce hypophosphataemia. Dosage and Administration: The recommended adult dosage of sucralfate in the treatment of duodenal or gastric ulcer is 1g 3 times daily on an empty stomach, 1 hour before meals or 2 hours after meals, and 1g at bedtime. Treatment should be continued until the ulcer is healed, or if endoscopic reassessment is not possible, for up to 8 weeks.