A comparison of enprostil and ranitidine in treatment of duodenal ulcer

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.

Ranitidine in the treatment of duodenal ulcer disease: relationship between antisecretory effect and ulcer healing rate

The relationship between drug-induced suppression of intragastric acidity and the rate of duodenal ulcer healing was examined using data for a single drug, ranitidine, from 156 clinical trials involving 16,362 patients together with data on acid suppression from 37 studies of intragastric acidity in 630 subjects. In these studies ranitidine was given in doses ranging from 150 mg to 1200 mg per day administered in 9 different dosage regimens. The overall percentage of patients whose duodenal ulcers healed at 2 and 4 weeks on the different regimens was highly correlated with the percentage suppression of 24-hour intragastric acidity induced by different regimens. Thus the therapeutic benefit of a given ranitidine dosage regimen in healing duodenal ulcers relates directly to its antisecretory effect.

Effect of two-week treatment with enprostil (35 micrograms twice a day) on 24-hour serum gastrin levels

After a meal, a single dose of enprostil, a synthetic dehydroprostaglandin E2, inhibits gastrin level in both normal subjects and patients with duodenal ulcer, whereas H2 blockers exaggerate the postprandial gastrin response. However, the effect of prolonged treatment with enprostil on the gastrin profile is unknown. The aim of this study was to compare serum gastrin levels over a 24-hr period before (day 0) and on the last day (day 14) of a two-week course of enprostil (35 micrograms twice a day). Nine healthy volunteers (four women and five men), ages 29 +/- 5 years (range 23-39) were studied twice during a 24-hr period. Serum gastrin was measured at 30-min intervals during the day and at 2-hr intervals during the night. Enprostil (35 micrograms) was taken after basal gastrin serum measurement at 8:00 AM and PM. Standardized meals were ingested at 8:30 AM, 12:30 PM, and 8:30 PM. The postprandial integrated serum gastrin response was calculated after the three meals (4-hr period). Fasting serum gastrin levels were similar for the two periods. Integrated postprandial gastrin response was significantly inhibited after breakfast and dinner (P less than 0.001). Average results are expressed as mean +/- SEM (pmol/min/liter). During the night, gastrin levels were significantly decreased by enprostil. After 14 days, the inhibition of gastric acid secretion, which induces an increase of gastrin release with other antisecretory drugs, remained counterbalanced by the antigastrin properties of enprostil.

A synthetic prostaglandin E2 analogue, enprostil, hastens gastric emptying of solids in patients with an active duodenal ulcer

The effect of gastric emptying of two doses (35 and 70 micrograms) of enprostil given orally was evaluated in eight patients with endoscopically confirmed duodenal ulcer. Gastric emptying of a radiolabelled solid meal was assessed with the use of a gamma camera. Enprostil dose-dependently accelerated gastric emptying of solids; the gastric emptying index, Ix, increased from 1.62 +/- 0.38 min-1.10(-2) after placebo to 2.77 +/- 0.56 min-1.10(-2) after 35 micrograms enprostil (p less than 0.05 versus placebo) and to 3.65 +/- 0.64 min-1.10(-2) after 70 micrograms enprostil (p less than 0.005 versus placebo). The fraction of the radiolabelled food retained in the stomach at the end of the gastric emptying examination (that is, after 90 min) amounted to 50.5 +/- 6.9% after placebo, 35.2 +/- 7.4% after 35 micrograms enprostil, and 24.1 +/- 8.4% after 70 micrograms enprostil. It is concluded that enprostil elicits a significant speeding up of solid-phase gastric emptying in duodenal ulcer patients.

A comparison of low-dose maintenance treatment with enprostil against ranitidine in the prevention of duodenal ulcer recurrence

Enprostil, a prostaglandin E2 analogue, is effective in healing acute duodenal ulcer but its value in preventing recurrence, when given daily for maintenance therapy, is uncertain. In this three-centre study we compared enprostil and ranitidine maintenance therapy; the latter is known to reduce duodenal ulcer relapse rates. Patients whose duodenal ulcers had been healed by treatment with an H2-receptor antagonist were randomized to receive single-blind treatment with either 35 micrograms enprostil (n = 64) or 150 mg ranitidine (n = 64) at bedtime for periods of up to 1 year. Endoscopy was routinely performed at 3 months at one centre, and at 6 and 12 months at all three centres, or whenever ulcer symptoms recurred. Clinical assessment and laboratory investigations were performed every 3 months. Relapse, defined as recurrent ulcer with or without pain, or erosions with pain, was significantly greater in patients on enprostil, the comparative rates at 3, 6 and 12 months were: enprostil 23, 31 and 36% ranitidine 6, 12 and 17% (P = 0.013; P = 0.03 and P = 0.03, respectively). Thirty-one patients reported adverse events, the most common being headache (enprostil = 6, ranitidine = 2) and mild diarrhoea (enprostil = 6, ranitidine = 0). Four patients on enprostil were withdrawn for adverse events, although none terminated because of diarrhoea. There were no clinically significant changes in haematology or biochemistry. Enprostil may reduce duodenal ulcer relapse but at a dose of 35 micrograms nightly, it is less effective than 150 mg ranitidine nightly.

Ranitidine. An updated review of its pharmacodynamic and pharmacokinetic properties and therapeutic use in peptic ulcer disease and other allied diseases

Ranitidine, a histamine H2-receptor antagonist, is now well established as a potent inhibitor of gastric acid secretion effective in the treatment and prophylaxis of gastrointestinal lesions aggravated by gastric acid secretion. Therapeutic trials involving several thousands of patients with peptic ulcer disease confirm that ranitidine 300mg daily administered orally in single or divided doses is at least as effective as cimetidine 800 to 1000mg daily in increasing the rate of healing of duodenal and gastric ulcers. Similar dosages of ranitidine have been shown to relieve the symptoms of reflux oesophagitis and heal or prevent gastrointestinal damage caused by ulcerogenic drugs. Ranitidine 150mg orally at night maintains ulcer healing in the long term. Ranitidine has also demonstrated good results in the treatment of Zollinger-Ellison syndrome and in the prevention of aspiration pneumonitis when given prior to surgery and to pregnant women at full term. It may also have a place in the management of acute upper gastrointestinal bleeding and in the prevention of stress ulcers in the intensive care setting, although these areas require further investigation. Ranitidine has been used safely in obstetric patients during labour, in children, the elderly, and in patients with renal impairment when given in appropriate dosages. The drug is very well tolerated and is only infrequently associated with serious adverse reactions or clinically significant drug interactions. Even at high dosages, ranitidine appears devoid of antiandrogenic effects. Ranitidine is clearly comparable or superior to most other antiulcer agents in the treatment and prevention of a variety of gastrointestinal disorders associated with gastric acid secretion. With its favourable efficacy and tolerability profiles, ranitidine must be considered a first-line agent when suppression of gastric acid secretion is indicated.