Histamine2-receptor antagonists. Standard therapy for acid-peptic diseases (2)

Current Status of Gastric Proton Pump Inhibitors in the Treatment of Acid-Peptic Disease

Proton pump inhibitors represent an important advance in the treatment of acid-peptic disease. Omeprazole, the prototype of the drug class, produces a profound and sustained degree of gastric acid suppression. Recent studies confirm earlier reports that omeprazole 20 mg/d is generally more effective than standard histamine2 receptor antagonist (H2RA) dosage regimens in treating duodenal ulcer (DU), gastric ulcer (GU), and erosive esophagitis. Omeprazole tends to accelerate DU and GU healing, especially during the first 2 weeks of treatment, and also accelerates mucosal healing in patients with all grades of esophagitis. Omeprazole is the drug of choice for treating patients with large or refractory ulcers, severe or refractory erosive esophagitis, Barrett's esophagus, and Zollinger-Ellison syndrome. Maintenance therapy with omeprazole seems to reduce ulcer recurrence and esophagitis, but optimal treatment regimens must be established. Dual therapy with omeprazole and amoxicillin shows encouraging results in eradicating Helicobacter pylori, reducing duodenal ulcer recurrence rates, and altering the natural history of peptic ulcer disease. Further studies are required to determine the efficacy of omeprazole in preventing nonsteroidal anti-inflammatory drug-induced ulcers and stress-related mucosal bleeding, and in treating upper gastrointestinal bleeding. Omeprazole is well-tolerated in the majority of patients receiving either short-term or long-term treatment. The type and frequency of adverse effects are similar to those reported with the H2RAs. There is no evidence to support genotoxicity or hypergastrinemia-induced enterochromaffin-like cell carcinoid of the stomach in patients receiving omeprazole treatment for more than 5 years. Omeprazole interacts selectively with hepatic P-450 and may potentially interact with phenytoin, warfarin, or diazepam. Pharmacoeconomic studies suggest that treatment with omeprazole provides a significant cost-savings over the H2RAs in patients with moderate to severe erosive esophagitis and possibly in patients with DU. Lansoprazole, a newly developed proton pump inhibitor, seems to offer no clear advantage over omeprazole.

Reduction in radiation-induced lymphocytopenia by famotidine in patients undergoing radiotherapy for prostate cancer

BACKGROUND

Ionizing radiation causes a series of hematological alterations especially profound lymphocytopenia during and after the radiotherapy course. To investigate whether famotidine can reduce hematologic toxicity in patients treated with radiotherapy for prostate cancer.

METHODS

A total of 36 patients undergoing radiotherapy for prostate cancer were randomized to receive either placebo or famotidine tablets. Participants were pretreated with 40 mg of oral famotidine or placebo tablets twice daily, 4 and 3 hr before each radiotherapy fraction. The patients received external-beam radiotherapy up to 70 Gy. Complete blood counts with differential, platelet counts, and hemoglobin levels were obtained at baseline, biweekly during the treatment and once 4 weeks after the end of radiotherapy course. Magnitude of changes from baseline in the hematological parameters was determined and compared using Repeated Measures ANOVA.

RESULTS

Famotidine was well tolerated. A total of 112 blood samples were evaluated. A significant reduction in radiation-induced lymphocytopenia was noted in patients receiving famotidine than in patients receiving placebo (P = 0.006). No significant difference was observed between two groups for the decline in platelets, erythrocytes and leucocytes. For both groups, neutrophil, monocyte, eosinophil, and hemoglobin levels did not change significantly during the treatment.

CONCLUSIONS

Our results indicate that famotidine could result in a significant reduction in radiation-induced lymphocytopenia and may consequently increase radiotherapy efficacy as well as survival times. This radioprotective effect may be chiefly associated with its antioxidant and radical scavenging properties. Further studies are required to confirm these encouraging results.

Gastroenterostoma after Billroth antrectomy as a premalignant condition

Gastric stump carcinoma (GSC) following remote gastric surgery is widely recognized as a separate entity within the group of various types of gastric cancer. Gastrectomy is a well established risk factor for the development of GSC at a long time after the initial surgery. Both exo- as well as endogenous factors appear to be involved in the etiopathogenesis of GSC, such as achlorhydria, hypergastrinemia and biliary reflux, Epstein-Barr virus and Helicobacter pylori infection, atrophic gastritis, and also some polymorphisms in interleukin-1β and maybe cyclo-oxygenase-2. This review summarizes the literature of GSC, with special reference to reliable early diagnostics. In particular, dysplasia can be considered as a dependable morphological marker. Therefore, close endoscopic surveillance with multiple biopsies of the gastroenterostomy is recommended. Screening starting at 15 years after the initial ulcer surgery can detect tumors at a curable stage. This approach can be of special interest in Eastern European countries, where surgery for benign gastroduodenal ulcers has remained a practice for a much longer time than in Western Europe, and therefore GSC is found with higher frequency.

A review of stress-related mucosal disease

OBJECTIVE

To review and summarize the human and veterinary literature regarding stress-related mucosal disease (SRMD) pathogenesis, patient risk factors, and therapeutic options for prophylaxis and treatment.

ETIOLOGY

SRMD is a common sequela of critical illness in human patients. Development of SRMD results from splanchnic hypoperfusion, reperfusion injury, and exposure of the gastric mucosa to acid, pepsin, and bile acids following breakdown of the gastric mucosal defense system. Human patients with the highest risk of stress ulceration include those with respiratory failure necessitating mechanical ventilation greater than 48 h or coagulopathy. Currently, little is known about the incidence and pathophysiology of SRMD in critically ill veterinary patients.

DIAGNOSIS

A presumptive diagnosis can be made in high-risk patient populations following detection of occult or gross blood in nasogastric tube aspirates, hematemesis, or melena. Definitive diagnosis is achieved via esophagogastroduodenoscopy. Lesions are localized to the acid-producing portions of the stomach, the fundus, and body.

THERAPY

Therapy is aimed at optimization of tissue perfusion and oxygenation. Pharmacologic interventions are instituted to increase intraluminal pH and augment natural gastric defenses. Histamine(2)-receptor antagonists, proton pump inhibitors, and sucralfate are the mainstays of therapy. In people, clinically significant bleeding may necessitate additional interventions (eg, packed red blood cell transfusions, endoscopic, or surgical hemostasis).

PROGNOSIS

Mortality is increased in people with clinically significant bleeding compared to those patients who do not bleed. Institution of prophylaxis is recommended in high-risk patients. However, no consensus exists regarding initiation of prophylaxis, preference of frontline drug class, or indication for discontinuation of therapy. The prognosis of veterinary patients with SRMD remains unknown at this time.

Clinical evidence of interaction between clopidogrel and proton pump inhibitors

Clopidogrel is approved for reduction of atherothrombotic events in patients with cardiovascular (CV) and cerebrovascular disease. Dual antiplatelet therapy with aspirin and clopidogrel decreases the risk of major adverse cardiac events after acute coronary syndrome or percutaneous coronary intervention, compared with aspirin alone. Due to concern about gastrointestinal bleeding in patients who are receiving clopidogrel and aspirin therapy, current guidelines recommend combined use of a proton pump inhibitor (PPI) to decrease the risk of bleeding. Data from previous pharmacological studies have shown that PPIs, which are extensively metabolized by the cytochrome system, may decrease the ADP-induced platelet aggregation of clopidogrel. Results from retrospective cohort studies have shown a higher incidence of major CV events in patients receiving both clopidogrel and PPIs than in those without PPIs. However, other retrospective analyses of randomized clinical trials have not shown that the concomitant PPI administration is associated with increased CV events among clopidogrel users. These controversial results suggest that large specific studies are needed. This article reviews the metabolism of clopidogrel and PPIs, existing clinical data regarding the interaction between clopidogrel and PPIs, and tries to provide recommendations for health care professionals.

The H2 receptor antagonist nizatidine is a P-glycoprotein substrate: characterization of its intestinal epithelial cell efflux transport

The aim of this study was to elucidate the intestinal epithelial cell efflux transport processes that are involved in the intestinal transport of the H(2) receptor antagonist nizatidine. The intestinal epithelial efflux transport mechanisms of nizatidine were investigated and characterized across Caco-2 cell monolayers, in the concentration range 0.05-10 mM in both apical-basolateral (AP-BL) and BL-AP directions, and the transport constants of P-glycoprotein (P-gp) efflux activity were calculated. The concentration-dependent effects of various P-gp (verapamil, quinidine, erythromycin, ketoconazole, and cyclosporine A), multidrug resistant-associated protein 2 (MRP2; MK-571, probenecid, indomethacin, and p-aminohipuric acid), and breast cancer resistance protein (BCRP; Fumitremorgin C) inhibitors on nizatidine bidirectional transport were examined. Nizatidine exhibited 7.7-fold higher BL-AP than AP-BL Caco-2 permeability, indicative of net mucosal secretion. All P-gp inhibitors investigated displayed concentration-dependent inhibition on nizatidine secretion in both directions. The IC(50) of verapamil on nizatidine P-gp secretion was 1.2 x 10(-2) mM. In the absence of inhibitors, nizatidine displayed concentration-dependent secretion, with one saturable (J(max) = 5.7 x 10(-3) nmol cm(-2) s(-1) and K(m) = 2.2 mM) and one nonsaturable component (K(d) = 7 x 10(-4) microL cm(-2) s(-1)). Under complete P-gp inhibition, nizatidine exhibited linear secretory flux, with a slope similar to the nonsaturable component. V(max) and K(m) estimated for nizatidine P-gp-mediated secretion were 4 x 10(-3) nmol cm(-2) s(-1) and 1.2 mM, respectively. No effect was obtained with the MRP2 or the BCRP inhibitors. Being a drug commonly used in pediatrics, adults, and elderly, nizatidine susceptibility to efflux transport by P-gp revealed in this paper may be of significance in its absorption, distribution, and clearance, as well as possible drug-drug interactions.

Acute upper gastrointestinal bleeding in operated stomach: Outcome of 105 cases

AIM: To compare the causes and clinical outcome of patients with acute upper gastrointestinal bleeding (AUGB) and a history of gastric surgery to those with AUGB but without a history of gastric surgery in the past.

METHODS: The causes and clinical outcome were compared between 105 patients with AUGB and a history of gastric surgery, and 608 patients with AUGB but without a history of gastric surgery.

RESULTS: Patients who underwent gastric surgery in the past were older (mean age: 68.1±11.7 years vs 62.8±17.8 years, P = 0.001), and the most common cause of bleeding was marginal ulcer in 63 patients (60%). No identifiable source of bleeding could be found in 22 patients (20.9%) compared to 42/608 (6.9%) in patients without a history of gastric surgery (P = 0.003). Endoscopic hemostasis was permanently successful in 26 out of 35 patients (74.3%) with peptic ulcers and active bleeding or non-bleeding visible vessel. Nine patients (8.6%) were operated due to continuing or recurrent bleeding, compared to 23/608 (3.8%) in the group of patients without gastric surgery in the past (P = 0.028). Especially in peptic ulcer bleeding patients, emergency surgery was more common in the group of patients with gastric surgery in the past [9/73 (12.3%) vs 19/360 (5.3%), P = 0.025]. Moreover surgically treated patients in the past required more blood transfusion (3.3±4.0 vs 1.5±1.7, P = 0.0001) and longer hospitalization time (8.6±4.0 vs 6.9±4.9 d, P = 0.001) than patients without a history of gastric surgery. Mortality was not different between the two groups [4/105 (3.8%) vs 19/608 (3.1%)].

CONCLUSION: Upper gastrointestinal bleeding seems to be more severe in surgically treated patients than in non-operated patients.

Bioequivalence of two oral formulations of nizatidine capsules in healthy male volunteers

PURPOSE

The purpose of this randomized, crossover study was to compare the bioavailability of a generic and an innovator formulation of nizatidine 300 mg capsules under fasting conditions.

METHODS

Twenty blood samples per period were collected from 20 healthy, Arab male volunteers over 16 h, plasma nizatidine concentrations were determined by HPLC assay, and pharmacokinetic parameters were determined by the non-compartmental method.

RESULTS

Mean+/-SD C(max), T(max), AUC(0-->t), AUC(0-->infinity), and t1/2 were 2.96+/-0.54 and 3.28+/-0.68 microg/ml, 1.31+/-0.70 and 0.93+/-0.38 h, 9.04+/-1.66 and 9.03+/-1.94 microg x h/ml, 9.17+/-1.64 and 9.12+/-1.94 microg x h/ml, and 1.64+/-0.21 and 1.58+/-0.22 h for the generic and innovator formulation, respectively. The parametric 90% confidence intervals on the mean of the difference between log-transformed values were 98.06% to 103.21%, 98.74% to 103.71%, and 83.37% to 101.34%, for AUC(0-->t), AUC(0-->infinity), and C(max), respectively.

CONCLUSION

The results indicate that these two formulations are equivalent in the rate and extent of absorption.

Medication use and prescribing considerations for elderly patients

Older adults consume more medications than any other segment of the population. Increasing lifespan means that more people will live into old age, frequently with disabilities and conditions man-aged by medications. Age-associated physiologic changes, medication use patterns, and adverse drug effects and interactions place the older adult at high risk for medication-related problems. Older adults living in institutions, those with complex medical problems,and those who do not adhere to medication regimens are at highest risk for negative health outcomes from medication mishaps. Dentists must be able to identify older adults who are susceptible to adverse drug events and to recognize which medications are most likely to precipitate problems.

Occurrence of ventilator-associated pneumonia in mechanically ventilated pediatric intensive care patients during stress ulcer prophylaxis with sucralfate, ranitidine, and omeprazole

PURPOSE

The purpose of the study was to evaluate the effects of sucralfate, ranitidine, and omeprazole use on incidence of ventilatory-associated pneumonia (VAP) and mortality in ventilated pediatric critical care patients.

MATERIALS AND METHODS

This prospective study was conducted at the pediatric intensive care unit (PICU) between August 2000 and February 2002. A total of 160 patients who needed mechanical ventilation were randomized into 4 groups according to the computer-generated random number table: group (S), (n = 38) received sucralfate suspension 60 mg/kg/d in 4 doses via the nasogastric tube that was flushed with 10 mL of sterile water; group (R), (n = 42) received ranitidine 2 mg/kg/d intravenously in 4 doses; group (O), (n = 38) received omeprazole 1 mg/kg/d intravenously in 2 doses; and group (P), (n = 42) did not receive any medication for stress ulcer prophylaxis. Treatment was begun within 6 hours of PICU admission.

RESULTS

Seventy patients (44%) developed VAP. VAP rate was 42% (16 of 38) in the sucralfate group, 48% (20 of 42) in the ranitidine group, 45% (17 of 38) in the omeprazole group, and 41% (17 of 42) in the nontreated group. Overall mortality rate was 22% (35 of 160); it was 21% (8 of 38) in the sucralfate group, 23% (10 of 42) in the ranitidine group, 21% (8 of 38) in the omeprazole group, and 21% (9 of 42) in the nontreated group. Our results did not show any difference in the incidence of VAP and mortality in mechanically ventilated PICU patients treated with ranitidine, omeprazole, or sucralfate, or nontreated subjects (P =.963, confidence interval [CI] = 0.958-0.968; P =.988, CI = 0.985-0.991, respectively). Nine patients (5.6%) had macroscopic bleeding. There was no statistically significant difference in macroscopic bleeding between groups.

CONCLUSIONS

Our results did not show any difference in the incidence of VAP, macroscopic stress ulcer bleeding, and mortality in the mechanically ventilated PICU patients treated with ranitidine, omeprazole, or sucralfate, or nontreated subjects. None of the treatment regimens increased VAP compared with the nontreated group. Because there is insufficient data about stress ulcer prophylaxis and VAP in the pediatric age group, more studies with larger numbers of patients are needed.

Lansoprazole for maintenance of remission of erosive oesophagitis

Gastro-oesophageal reflux disease, which is experienced daily by a significant proportion of individuals, may result in serious sequelae such as erosive oesophagitis. Short-term treatment with acid antisecretory therapy (a proton pump inhibitor or a histamine H(2) receptor antagonist) is highly effective in healing the erosive oesophagitis lesion. However, numerous studies confirm that unless maintenance therapy is initiated virtually all patients will experience oesophagitis relapse within 1 year, as well as an increasing severity of oesophagitis and risk for complications such as Barrett's oesophagus and adenocarcinoma. Studies evaluating the efficacy of proton pump inhibitor and H(2) antagonist maintenance therapy have found that only the proton pump inhibitors significantly reduce the incidence of oesophagitis relapse. Pharmacoeconomic studies have also confirmed that proton pump inhibitor maintenance therapy is cost effective, by virtue of the ability of these agents to reduce the incidence of relapse as well as prolong the time to relapse and increase the number of weeks per year that patients are without symptoms. Lansoprazole, a member of the proton pump inhibitor class of agents, has been extensively studied in the treatment of patients with a variety of acid-related disorders. Among those with erosive oesophagitis, maintenance therapy with lansoprazole 15 or 30mg once daily is highly effective in preventing relapse. Studies have documented that lansoprazole 15 and 30mg once daily for six months prevents oesophagitis relapse in up to 81 and 93% of patients, respectively, with comparable percentages of patients remaining in remission after 1 year of treatment. These high rates of remission have also been observed in studies of patients with lesions that were difficult to heal at baseline (resistant to healing with at least 3 months of H(2) antagonist therapy). Moreover, lansoprazole produces high remission rates regardless of the grade of erosive oesophagitis before acute healing. Among symptomatic patients with heartburn, lansoprazole provides rapid and effective relief of daytime and night-time heartburn and prevents relapse of symptoms. Lansoprazole has a wide margin of safety and is well tolerated when administered as monotherapy in short- and long-term clinical trials. Taken together these data suggest that proton pump inhibitor therapy represents the preferred and ideal long-term management strategy for the patient with erosive oesophagitis. Lansoprazole is a well-established member of this class of agents and, as such, has an extensive body of literature that supports its safety, tolerability and clinical efficacy in preventing relapse in these patients.

A review of epidemiological studies on cancer in relation to the use of anti-ulcer drugs

H2-receptor antagonists have been widely used since the late 1970s for the treatment of gastrointestinal ulcers and other benign conditions of the stomach, oesophagus and duodenum. Several case reports suggested that long-term therapy with H2-receptor antagonists, mainly cimetidine and ranitidine, might increase the risk of gastric cancer. After early case reports, at least six analytical epidemiological studies (two cohort and four case-control) were published, including a total of about 1000 cases of gastric cancer. The relative risks (RR) were systematically and substantially elevated in the first year since starting H2-receptor antagonist use, and levelled off in the following years. Some excess risk was still apparent during the first 5 years of drug use, probably due to incorrect diagnosis and treatment of pre-existing neoplastic gastric lesions, but the estimated RR was not above unity for > or = 10 years since starting drug treatment in the two studies including information on long-term use. The findings of analytical epidemiological studies are thus consistent with the absence of a causal association between H2-receptor antagonist use and gastric cancer risk. Data on oesophageal and colorectal cancer do not support a relevant relation between cimetidine use and the risk of these neoplasms. With reference to total cancer mortality, in a Danish cohort study, for males the RR was 1.9 in the first year, and 1.4 in the first 5 years; corresponding values for females were 1.7 and 1.5. In a British cohort study, the RR was 3.4 in the first year, and 1.3 in the years 2-10. The excess risk in the first year was essentially due to gastric cancer. Post-marketing surveillance data for omeprazole and other proton pump inhibitors are much scantier than for H2-receptor antagonists, particularly on long-term use.

H2-receptor antagonists in the treatment of functional (nonulcer) dyspepsia: a meta-analysis of randomized controlled clinical trials

AIM

To perform a meta-analysis evaluating the efficacy of H2-receptor antagonists in functional (nonulcer) dyspepsia.

SELECTION OF STUDIES

A Medline search was used to identify placebo controlled randomized clinical trials, using the subject headings dyspepsia and H2-receptor antagonist.

OUTCOME MEASURES

Global assessment by the patient of dyspepsia symptoms, improvement of epigastric pain and complete relief of epigastric pain.

RESULTS

Twenty-two studies met the inclusion criteria, 15 of which reported the active drug to be superior to placebo. Many studies suffered from suboptimal study design. The odds ratio in favour of active drug was 1.48 (95% confidence interval: 0.9-2.3) for global assessment of dyspepsia symptoms, 2.3 (95% CI: 1.6-3.3) for improvement of epigastric pain, and 1.8 (95% CI: 1.2-2.8) for complete relief of epigastric pain.

CONCLUSION

There is some evidence that H2-receptor antagonists are superior to placebo in functional dyspepsia, but larger studies evaluating higher doses of H2-receptor antagonists and of longer duration are necessary to determine the exact effect size.

Acid peptic disease in the elderly

GERD and peptic ulcer disease are important diseases in the elderly. GERD presents similarly in the elderly and the young, although elderly patients may have less severe symptoms yet more severe mucosal disease and a higher prevalence of BE. Although the prevalence of H. pylori is falling, the elderly remain at risk for peptic ulcer because of the widespread use of NSAIDS. The presentation of peptic ulcer disease in the elderly can be subtle and atypical when compared with younger patients, leading to a delay in diagnosis. Because of comorbidity in the aged, peptic ulcer disease and its complications result in increased morbidity and mortality rates.

Abnormal functional and morphological regulation of the gastric mucosa in histamine H2 receptor-deficient mice

To clarify the physiological roles of histamine H2 receptor (H2R), we have generated histamine H2R-deficient mice by gene targeting. Homozygous mutant mice were viable and fertile without apparent abnormalities and, unexpectedly, showed normal basal gastric pH. However, the H2R-deficient mice exhibited a marked hypertrophy with enlarged folds in gastric mucosa and an elevated serum gastrin level. Immunohistochemical analysis revealed increased numbers of parietal and enterochromaffin-like (ECL) cells. Despite this hypertrophy, parietal cells in mutant mice were significantly smaller than in wild-type mice and contained enlarged secretory canaliculi with a lower density of microvilli and few typical tubulovesicles in the narrow cytoplasm. Induction of gastric acid secretion by histamine or gastrin was completely abolished in the mutant mice, but carbachol still induced acid secretion. The present study clearly demonstrates that H2R-mediated signal(s) are required for cellular homeostasis of the gastric mucosa and normally formed secretory membranes in parietal cells. Moreover, impaired acid secretion due to the absence of H2R could be overcome by the signals from cholinergic receptors.

Pantoprazole versus ranitidine in the treatment of duodenal ulcer: a multicenter study in Brazil

OBJECTIVE

The aim of this study was to compare the effectiveness and tolerance of pantoprazole versus ranitidine in the treatment of duodenal ulcers in the Brazilian population.

METHODS

A total of 222 patients with active duodenal ulcers (DU) were randomly allocated to a double dummy blind treatment, either with ranitidine (RAN) 300 mg (111, aged from 20-68 yr old, 56 female) or with pantoprazole (PANT) 40 mg (111 patients, 18-70 yr old, 45 female). After a 2-wk course of treatment, each patient was clinically and endoscopically assessed for ulcer healing. Failure to heal required a further 2-wk course of treatment and a new evaluation thereafter.

RESULTS

In all, 77 of the 103 patients in the PANT group (74.8%) and 42 of the 94 patients in the RAN group (44.7%) who completed the study had ulcer healing after one 2-wk treatment course, and an additional 23 in the PANT group (22.3%) and 28 in the RAN group (29.8%) after the second 2-wk treatment course, totaling 100 (97.1%) and 70 (74.5%), respectively. Therapeutic gain in favor of pantoprazole was significant both at the end of the first and the second 2-wk treatment course (p<0.001). At 2 wk, symptoms remission was significantly higher in the PANT group (97.6%) than with the RAN group (77.5%) (p<0.001). The Intention-to-treat analysis showed results statistically similar to those observed in the per-protocol analysis. Minor adverse events were reported by four patients in the PANT group and three in the RAN group. No relevant laboratory abnormalities were seen. No patient withdrew from the study due to adverse events.

CONCLUSIONS

Our results show that pantoprazole is more effective than ranitidine in the treatment of duodenal ulcer providing faster ulcer healing in most patients (97.1%), in 4 wk. Adverse events were rare and were similar in both groups, and had no influence on the therapeutic outcome.

The use of intravenous H2-receptor antagonists in a tertiary care hospital

OBJECTIVE

The rationale for the widespread use of intravenous H2 receptor antagonists(IVH2 RA) in hospitalized patients is not clear. We therefore examined prescribing patterns and, using strict criteria, determined whether use was appropriate. Cost of administration and potential savings were also determined.

METHODS

Data were obtained prospectively on 100 consecutive patients prescribed intravenous ranitidine and retrospectively on patients admitted with gastrointestinal (GI) bleeding.

RESULTS

For the prospective study, various indications for prescribing intravenous ranitidine were given, including postoperative patients and patients treated with steroids. Using criteria from published literature 80% of the use was considered inappropriate. Nearly 40% of the doses were given while the patient was tolerating oral intake. Creatinine clearance was impaired in 26% of patients, though only one had dosage reduction. Estimated annual cost of intravenous ranitidine was $317,000. The retrospective study of 86 consecutive patients admitted with GI bleeding revealed that all patients received intravenous ranitidine on admission, none of which was considered appropriate. The final diagnoses were peptic ulcer (49), colonic process (11), esophagitis (seven), gastric erosions (five), esophageal varices (five), Mallory-Weiss tears (four), duodenitis (two), no diagnosis (three), and jejunal ulcer (one).

CONCLUSIONS

Inappropriate use of intravenous ranitidine is common. This includes inappropriate indication, dosage, and duration of use. Large financial benefits could have been obtained if close attention was given to prescribing patterns.

Double-blind comparison [correction of Double-blind, placebo-controlled comparison] of rabeprazole 20 mg vs. omeprazole 20 mg in the treatment of erosive or ulcerative gastro-oesophageal reflux disease. The European Rabeprazole Study Group

BACKGROUND

Rabeprazole sodium is the most recent member of a class of substituted benzimidazole molecules known as proton pump inhibitors. Other proton pump inhibitors have been shown to be effective in healing oesophagitis.

METHODS

In this randomised, double-blind, multicentre study, conducted at 27 European sites, the efficacy and safety of rabeprazole and omeprazole were compared in patients with erosive or ulcerative gastro-oesophageal reflux disease (GERD).100 patients received rabeprazole 20 mg, and 102 patients omeprazole 20 mg once daily for 4 or 8 weeks, with healing monitored by endoscopy.

RESULTS

Overall GERD healing rates observed and evaluated at weeks 4 and 8 were equivalent. Four-week healing rates for rabeprazole and omeprazole were 81%-81% and 92%-94% for 8-week healing. Rabeprazole-treated patients had similar relief of the frequency and intensity of heartburn to those treated with omeprazole. Both drugs were well tolerated over the 8-week treatment period. Mean changes in fasting serum gastrin were comparable. No significant differences in laboratory parameters were seen. Biopsies for argyrophil ECL cell histology at the end-point revealed a similar distributions of hyperplasia grades to those at baseline in both groups. Biopsies of body and antral mucosa for other parameters were similar between treatments for Helicobacter pylori colonization, presence or degree of inflammation, atrophy or intestinal metaplasia at the end-point.

CONCLUSION

In this study, GERD healing rates following rabeprazole 20 mg once daily were equivalent to those obtained with omeprazole 20 mg once daily. Both treatments resulted in a comparable relief of the frequency and intensity of heartburn associated with this disease, and both were well tolerated.

Pharmacokinetics of famotidine in patients with cystic fibrosis

Famotidine pharmacokinetics were studied in 13 patients with severe cystic fibrosis (CF) ranging from 10 to 47 years of age and 25 to 72 kg in weight. Patients were randomized to first receive famotidine either 20 mg intravenously or 40 mg orally. Twelve patients were crossed over to the alternate treatment. Repeated blood samples were obtained over 12 hours after intravenous and oral administration and urine was collected over 24 hours for quantitation of famotidine by means of high-performance liquid chromatography (HPLC). A compartment model-dependent approach was used to characterize the disposition of famotidine. From the intravenous data, the mean +/- standard deviation elimination half-life (t1/2) was 2.11 +/- 0.75 hours, the total clearance (Cl) was 0.79 +/- 0.41 L/kg/hr, the renal clearance was 0.57 +/- 0.26 L/kg/hr, the fraction eliminated unchanged in the urine was 83% +/- 16%, and the apparent volume of distribution (Vdss) was 1.33 +/- 0.53 L/kg. The bioavailability determined from comparison of intravenous and oral area under the curve data was 71% +/- 27%. Results of this study support an initial famotidine dose of 20 mg intravenously or 40 mg orally every 12 hours in patients with CF who are older than 9 years of age.

Ranitidine bismuth citrate in the treatment of Helicobacter pylori infection and duodenal ulcer

OBJECTIVE

To review the clinical pharmacology of ranitidine bismuth citrate in the treatment of Helicobacter pylori (HP) infection and duodenal ulcer.

DATA SOURCES

A MEDLINE search of the English-language literature from 1992 to January 1997 was conducting using the key terms Tritec, ranitidine, and bismuth. References of articles pertaining to treatment of duodenal ulcer or HP were extensively searched for relevant sources.

DATA EXTRACTION

All articles pertaining to ranitidine bismuth citrate were considered for inclusion, with emphasis placed on randomized, double-blind trials. Priority was placed on data pertaining to regimens that are currently approved by the Food and Drug Administration for the treatment of duodenal ulcer in conjunction with HP.

DATA SYNTHESIS

Each tablet of ranitidine bismuth citrate 400 mg contains 162 mg of ranitidine base, 128 mg of trivalent bismuth, and 110 mg of citrate. It uses the acid-suppressive actions of ranitidine and the antimicrobial and mucosal protective effects of bismuth to eradicate HP. Ranitidine bismuth citrate in conjunction with clarithromycin represents one of four treatment regimens currently approved in the US for duodenal ulcer associated with HP infection. In four double-blind, randomized trials, this agent has achieved HP eradication rates of 73-94% and duodenal ulcer healing rates of 73-89%. It is given twice daily for 28 days, and is associated with very low rates of adverse effects.

CONCLUSIONS

Relative to some therapeutic alternatives, ranitidine bismuth citrate plus clarithromycin may be simpler to take and have less adverse effects, but may be more expensive. Compared with omeprazole plus clarithromycin, it is less expensive, may have lower ulcer healing rates, but may be more effective in eradicating HP. The role of ranitidine bismuth citrate will continue to evolve as more patients are treated, and other regimens continue to be tested for duodenal ulcer healing and HP eradication.

Gastrointestinal diseases in women

Gastrointestinal disorders are among the most common disorders for which women seek medical attention. Most gastrointestinal diseases in women are not inherently different from those that occur in men. There are several disorders, however, that occur more frequently or manifest themselves differently in women. This article reviews common gastrointestinal disorders affecting women. The pathophysiology, clinical manifestations, management, and gender-specific issues of gastroesophageal reflux disease, peptic ulcer disease, irritable bowel syndrome (IBS), and inflammatory bowel disease (IBD) are discussed.

Gastroprotective effect of MX1 (a novel salt of the active metabolite of roxatidine with a complex of bismuth and citric acid) against stress ulcers in rats

We have studied the effect of the newly synthesized agent MX1, a salt of the active metabolite of the H2-blocker roxatidine with a complex of bismuth and citric acid (N-[3-(3-(1-piperidinylmethyl)phenoxy)propyl]-hydroxyacetamide+ ++ -2-hydroxypropane-1,2,3-tricarboxilate-bismuth(3+) complex), against restraint stress ulcers in rats (24 h immobilization). The effects of MX1 (12.5, 50, 125, 184 and 250 mg kg-1) were compared with the effects of equimolar doses of roxatidine (6.5, 25, 70, 100 and 140 mg kg-1) and bismuth subcitrate (6.5, 25, 70, 100 and 140 mg kg-1). The results show that MX1-pre-treatment, at all the doses used, significantly reduces the mean number and size of ulcers. Even at the lowest dose the number of ulcers was reduced by 64.3% and the size of the ulcer by 55.9%. Roxatidine (25, 70, 100 and 140 mg kg-1) dose-dependently reduces ulcer size and number by 24.6, 55.6, 85.3 and 89.0% and by (+7.2), 14.3, 57.1 and 67.9%, respectively. Bismuth subcitrate significantly reduces ulcer size and number only at the highest dose employed (-28.5 and -44.8%, respectively). The morphometric results have been confirmed histomorphologically. The results suggest that MX1 has a gastroprotective effect against stress-induced ulcers which is similar to that of the parent compound and more pronounced than that of bismuth subcitrate.

Concurrent use of antiulcerative agents

Many physicians prescribe more than one antiulcerative agent (AUA) simultaneously to the same patient, although there is little evidence to support this practice. The purposes of this study were to (a) determine patient factors associated with the concurrent use of these agents and (b) estimate the excess costs generated by the prescription of multiple rather than a single agent. We conducted a case-control study of concurrent AUA users among New Jersey Medicaid enrollees age 65 years and older. To evaluate the excess cost generated by the ongoing prescription of an additional AUA, we measured the additional drug expenditures associated with each regimen of concurrent use. Nearly 1 in 15 AUA users (6.6%) met our conservative definition of concurrent AUA use. In a multiple logistic regression model, previous gastrointestinal procedure, use of a nonsteroidal anti-inflammatory drugs, nursing home residency, and recent hospitalization for more than 20 days were all predictors of concurrent use of more than one AUA. No association was found with age, sex, or number of pharmacies used. The upper bound estimate of the cost generated by the concurrent prescription of a second AUA was $210 (range: $2-$942) over the 180-day study period, with a lower bound of $151 (range: $1-$449). Annually, such excess cost would range from $301 to $420 per patient. This would account for between $457 million and $637 million per year for the nation's elderly if these patterns are generalizable. Despite the lack of evidence of therapeutic benefit from multiple concurrent AUA use in most patients, this practice is fairly common. Besides introducing the risk of additional costs and side effects in the absence of additional efficacy, the costs of such duplicative prescribing are substantial.

Comparison of omeprazole and ranitidine for stress ulcer prophylaxis

Stress ulcer prophylaxis protects against clinically important gastrointestinal bleeding and has gained widespread use. This study compares the efficacy of omeprazole to ranitidine for this indication. This was a prospective, randomized clinical trial. Sixty-seven high-risk patients were randomized to receive either ranitidine 150 mg (N = 35) intravenously daily or omeprazole 40 mg (N = 32) daily orally or by nasogastric route. Patients were monitored for clinically important bleeding. There was no statistically significant difference between treatment groups in the number of patients enrolled, gender, race, or age. The study groups were comparable in regard to the severity of illness based on their similar APACHE II score, duration of ICU stay, duration of ventilator dependence, and mortality rate. A significant difference was found only in regard to the number of risk factors per patient. The ranitidine-treated group had 2.7 risk factors per patient while the omeprazole-treated group had 1.9 (P < 0.05). Eleven patients (31%) given ranitidine and two patients (6%) given omeprazole developed clinically important bleeding (P < 0.05). Nosocomial pneumonia developed in five patients (14%) receiving ranitidine and one patient (3%) receiving omeprazole (P > 0.05). We conclude that oral omeprazole is safe, effective, and clinically feasible for stress ulcer prophylaxis.

Reversion by histamine H2-receptor antagonists of plasma membrane alterations in ethanol-induced gastritis

Ethanol administration rapidly damages surface epithelial cells of rat stomach, leading to altered cellular plasma membranes. Histamine H2-receptor antagonists (H2RA) have been shown to have preventive properties against ethanol-induced gastric mucosal injury. Therefore, the possible reverting properties of H2RA (cimetidine, ranitidine, and famotidine) were tested in ethanol-induced gastritis. Subchronic ethanol administration elicited a histological profile of gastritis and alterations at the plasma membrane level (diminution of some phospholipids, increased cholesterol, and decreased activity of 5'-nucleotidase). H2RA administration to rats with gastritis promptly corrected the ethanol-induced mucosal damage. In addition, cytosolic enzyme activities (alcohol and lactate dehydrogenases) were also modified by gastritis and treatment with H2RA. In conclusion, our data suggest that H2RA improved restitution of the gastric mucosa contributing to the healing process of the gastric damage. The latter indicates reverting properties of H2RA on gastric damage, as well as their cytoprotective effect already described.

A risk-benefit assessment of drugs used in the eradication of Helicobacter pylori infection

Helicobacter pylori is the cause of chronic active gastritis and predisposes to peptic ulcer disease (PUD). Furthermore, H. pylori is linked to the pathogenesis of gastric lymphoma and gastric cancer. However, treatment of this infection has proven difficult. In the last decade, many antimicrobial compounds have been studied extensively as monotherapy as well as in combination with bismuth or acid-suppressive drugs. The individual drugs and the most important eradication regimens are discussed with special regard to their risks. In the past, highly complex multidrug regimens, fear of adverse effects and frequent eradication failures have hampered the broad acceptance of H. pylori-eradication therapies. Recently, new 1-week, low-dose combination regimens of 2 antibacterials with a proton pump inhibitor have consistently achieved eradication rates of 90% and more with an acceptably low rate of adverse effects. One week's standard triple therapy [tripotassium dicitrato bismuthate (or bismuth salicylate plus metronidazole plus tetracycline or amoxicillin) has been shown to be highly effective and tolerated better in combination with a proton pump inhibitor. This regimen is, however, more complex and has more adverse effects. Therefore, it is not recommended as first-line therapy. Equipped with these therapies physicians can now be strongly encouraged to use H. pylori eradication as the therapy of choice for patients with PUD and even extend this treatment to other H. pylori-associated disease conditions.

Risk of further ulcer complications after an episode of peptic ulcer bleeding

To identify the risk factors for developing recurrent ulcer complications after recovery from an episode of peptic ulcer bleeding 611 patients admitted with peptic ulcer bleeding were studied. Some 557 (91 per cent) were discharged without operation. A total of 22 patients were lost to follow-up and five were excluded as maintenance H2 blockers were required. Of the remaining 530 patients at risk, 169 (32 per cent) developed another complication (166 bleeding, three perforations) over a median follow-up period of 36 months. Patients with duodenal ulcers at the time of bleeding, previous history of peptic ulcer, previous bleeding, history of dyspepsia longer than 3 months, and a short interval between previous ulcer complications and the index bleed were more likely to develop further complications. Sex, age, smoking, coexisting illness, non-steroidal anti-inflammatory drugs intake and time taken to achieve ulcer healing had no predictive value.

Short-term treatment of gastric ulcer. A meta-analytical evaluation of blind trials

Gastric ulcer is relatively infrequent, and clinical trails are often based on small-sized samples. The aim of this study was to define the "gold standard" therapy of active gastric ulcer. We included all single- or double-blind clinical trials on the short-term treatment of gastric ulcer. All the articles published over the period 1977-1994 were reviewed. Meta-analysis was done with both fixed and random effect models; results were shown using Galbraith's radial plot. Forty-eight papers comprising 52 studies were evaluated. Cimetidine, ranitidine, and famotidine proved significantly better than placebo [odds ratio (OR) and 95% confidence interval (CI 95%) at four to six weeks were: 2.67 (2.03-3.52), 3.94 (2.28-6.80), 1.76 (1.08-2.88), respectively]. Cimetidine and ranitidine had results comparable with the newer H2 blockers [OR (CI 95%) at four weeks: 1.16 (0.91-1.47), 1.11 (0.80-1.55), respectively]. H2 blockers were proved comparable with either sucralfate [OR (CI 95%) at eight weeks: 0.81 (0.37-1.79)] or bismuth [OR (CI 95%) at four to six weeks: 0.67 (0.37-1.20)]. Omeprazole is more effective than H2 blockers [OR (CI 95%) at four weeks: 2.00 (1.57-2.55)]. It is concluded that H2 blockers are preferred to either a placebo or sucralfate for short-term gastric ulcer treatment; the newer H2 blockers do not have significant advantages over the older types; omeprazole can be regarded as the "gold standard" for active gastric ulcer treatment.

The development of clinical practice guidelines for treatment of peptic acid diseases in a VA ambulatory care clinic

The costly treatment of peptic acid diseases at a Veterans Affairs ambulatory care clinic prompted the development of clinical practice guidelines (CPGs) for the disorders. A committee consisting of a clinical pharmacist, the chiefs of ambulatory care and medicine, and a gastroenterologist guided the process. A consensus-style conference format involving medical staff and residents, pharmacists, and other health providers was chosen to develop the CPGs. Before the conference each participant received a list of key issues and literature on practice guidelines, and on peptic acid diseases and their treatment. At the conference the participants were divided into four groups; each group discussed specific key issues using a modified nominal group process. Recommendations from each group were made to the entire conference. Final recommendations were compiled into what was adopted and readily received as the CPGs for the institution.

Comparison of lansoprazole and omeprazole in the short-term management of duodenal ulcers in Taiwan

Lansoprazole is a novel H+/K+-ATPase inhibitor which exhibits a very potent and long-acting suppression of acid secretion. The object of this randomized, controlled trial was to compare duodenal ulcer healing rates after 4 weeks of treatment with a once-daily regimen of either 30 mg lansoprazole or 20 mg omeprazole. Of a total of 111 patients 57 received lansoprazole, whereas 54 received omeprazole. In intention-to-treat analysis at 4 weeks, 89.5% patients showed ulcer healing following treatment with lansoprazole compared with 83.3% of patients treated with omeprazole. Per protocol analysis indicated that 96.1% of patients treated with lansoprazole showed ulcer healing, compared with 93.6% of patients treated with omeprazole (NS). Age, smoking or ulcer size did not affect the ulcer healing rate. Both agents could effectively and quickly resolve ulcer symptoms. The Helicobacter pylori clearance was seen in 36 (73.5%) patients in the lansoprazole group and in 40 (80%) patients in the omeprazole group after four weeks of treatment (NS). In addition, both agents led to hypergastrinaemia, by approximately 1.6 fold. Adverse side effects included a few occurrences of reversible skin rash and constipation. It is concluded that lansoprazole elicits an adequate healing response and resolves symptoms of duodenal ulcer as well as omeprazole. Furthermore, lansoprazole is well tolerated with a few adverse side effects.

Pharmacological management of gastro-oesophageal reflux disease

Gastro-oesophageal reflux disease (GORD) ranges from episodic symptomatic reflux without oesophagitis to severe oesophageal mucosal damage, such as Barrett's metaplasia or peptic stricture. The multifactorial pathogenesis of GORD prevents medical cure of the disease. GORD is a chronic disease with a high tendency to relapse, requiring a long term treatment strategy in practically all patients. Complete healing of all mucosal lesions is not necessarily the aim of treatment in all patients. In milder forms of reflux disease, symptom relief is the most important goal. Many patients with mild GORD do well on symptomatic self-care with antacids and/or alginate. In addition, lifestyle changes should be advised to all patients: these improve symptoms and enhance the efficacy of therapy. In the acute treatment of GORD the prokinetic drug cisapride has been shown to be effective in relieving symptoms and healing grade I to II oesophagitis. Cisapride decreases symptomatic and endoscopic relapse in patients with mild GORD. Histamine H2-receptor antagonists are effective in relieving reflux symptoms in about 50% of patients, but with regard to healing, H2-antagonists appear to be mainly effective in grades I and II and not in higher grades of oesophagitis. Maintenance treatment with H2-antagonists is mainly symptomatically effective in patients with mild GORD. Proton pump inhibitors (PPIs) provide significantly higher healing rates of reflux oesophagitis than H2-antagonists, even in the more severe cases of oesophagitis and Barrett's ulcers. PPIs are also effective in patients with oesophagitis refractory to treatment with H2-antagonists. PPIs have become the drugs of first choice in healing of all patients with more severe forms of reflux oesophagitis, and increasingly also for patients with milder forms of oesophagitis, certainly those who fail to respond to other drugs. In maintenance treatment of GORD, PPIs are the most effective drugs, offering the possibility of keeping nearly all patients in remission with adjusted doses. Current patient data of up to 5 years indicate the safety of this strategy for this period, but the exact consequences of strong acid inhibition over a longer period still have to be clarified. At present, all but a few patients with GORD can be managed adequately by medical therapy.

Meta-analysis of the effect of placebo on the outcome of medically treated reflux esophagitis

BACKGROUND

To ascertain the placebo-induced effect in the treatment of reflux esophagitis, we reviewed all the English-language literature concerning the results of placebo-controlled trials of erosive/ulcerative esophagitis from 1976 to 1990. Twenty-two studies fulfilled our meta-analytic criteria.

RESULTS

After 4 to 8 weeks of treatment, active drugs (cimetidine, ranitidine, nizatidine, omeprazole, metoclopramide, sucralfate) were significantly more effective than placebo in the healing of esophagitis, with a pooled rate difference (PRD) of 0.22 in favor of the active drug, an odds ratio (OR) of 2.57 (confidence interval (CI) = 2.0-3.3). Pooled mean healing rate (+/- SD) with the active drug was 47.3 +/- 24.0%, as compared with 26.8 +/- 18.0% obtained with placebo after 4 to 8 weeks of treatment. With regard to symptomatic response, complete disappearance of symptoms was observed in an average of 31.6% active-treated patients and in 11.8% of placebo-treated patients, respectively. The PRD was 0.20, and the OR 2.25 (CI = 1.65-3.06). The incidence of side effects was not statistically different for the two treatment groups.

CONCLUSION

Placebo is a relatively inactive drug in the short-term treatment of erosive ulcerative reflux and does not appear to change the natural history of the disease.

A controlled study of ranitidine for the prevention of recurrent hemorrhage from duodenal ulcer

BACKGROUND

Hemorrhage is the most common complication of duodenal ulcer disease, but there is little information about the effectiveness and safety of long-term maintenance therapy with histamine H2-receptor blockers.

METHODS

We conducted a double-blind study in patients with endoscopically documented hemorrhage from duodenal ulcers. Patients were randomly assigned to maintenance therapy with ranitidine (150 mg at night) or placebo and were followed for up to three years. Endoscopy was performed at base line (to document that the ulcers had healed), at exit from the study, and when a patient had persistent ulcer symptoms unrelieved by antacids or had gastrointestinal bleeding. Symptomatic relapses without bleeding were treated with ranitidine; if the ulcer healed within eight weeks, the patient resumed taking the assigned study medication.

RESULTS

The two groups were similar at entry, which usually occurred about three months after the index hemorrhage. After a mean follow-up of 61 weeks, 3 of the 32 patients treated with ranitidine had recurrent hemorrhage, as compared with 12 of the 33 given placebo (P < 0.05). Half the episodes of recurrent bleeding were asymptomatic. One patient in the ranitidine group withdrew from the study because of asymptomatic thrombocytopenia during the first month.

CONCLUSIONS

For patients whose duodenal ulcers heal after severe hemorrhage, long-term maintenance therapy with ranitidine is safe and reduces the risk of recurrent bleeding.

Bolus infusion of famotidine: effects on gastric pH by repeated 12-hour doses of 20 mg in postoperative patients

This study was carried out to assess the efficacy of intravenous (IV) famotidine in suppressing gastric secretion over a 48-hour period. Twenty postoperative patients requiring a nasogastric tube received famotidine 20 mg IV every 12 hours and gastric pH was measured continuously by means of an indwelling probe. A baseline recording was performed over the first 4 hours and then the drug was infused every 12 hours (q12h) over a 15-minute period for the subsequent 48 hours. The mean pH value achieved during each time segment under active treatment was significantly higher (P < .001) than the mean basal value. Also the density distributions of minutes spent at the various pH units confirm that famotidine is highly effective (P < .001) in raising and maintaining gastric pH above 4.0 units during most of the drug-related period (44 hours). It can be concluded that repeated intravenous boli of famotidine 20 mg every 12 hours allow us to obtain an effective control of intragastric acidity. The antisecretory action is consistent over the total 48-hour period examined and therefore the use of intermittent infusion of famotidine seems to be advisable, as opposed to the recommended continuous IV administration of cimetidine and ranitidine. There is, however, a considerable intersubject variability in the antisecretory response to the drug.

Emerging strategies for managing peptic ulcer disease

The relationship between the inhibition of intragastric acidity and healing has been determined for both duodenal and gastric ulcers, with a stronger correlation being evident in duodenal ulcer. Omeprazole is clearly more effective than H2-receptor antagonists in healing duodenal ulcers and in the resolution of attendant symptoms. As the recommended treatment periods are shorter with omeprazole (e.g. 2-4 weeks) than with H2-receptor antagonists (4-8 weeks), omeprazole has also been shown to be more cost-effective. Long-term management strategies for peptic ulcer are evolving rapidly in the light of evidence that Helicobacter pylori eradication reduces or eliminates ulcer relapse. Regimens, such as omeprazole in combination with amoxycillin or clarithromycin, that both eradicate H. pylori and heal ulcers rapidly are appealing because they are simple, well tolerated, convenient and efficient in both healing ulcers and preventing relapse. This comprehensive approach appears to be evolving as the dominant strategy for the future treatment of peptic ulcer diseases. Gastric ulcer disease is also treated more effectively with omeprazole than with H2-receptor antagonists, both in terms of speed and reliability of healing, and in terms of symptom resolution. At 4 weeks, symptom resolution has been specifically examined in six comparative trials; in three of these, omeprazole was superior to the H2-receptor antagonist, and in the other three was at least as good as the H2-receptor antagonist. Omeprazole, 40 mg once daily, effectively heals non-steroidal anti-inflammatory drug (NSAID)-induced ulcers in about 90% of cases, even if NSAID therapy is continued, and is probably the treatment of choice for patients with ulcers requiring continued NSAID therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Peptic ulcer in the elderly--a double-blind, short-term study comparing nizatidine 300 mg with ranitidine 300 mg. GISU (Interdisciplinary Ulcer Study Group)

This was a randomized, double-blind, multicentre, short-term study comparing ranitidine and nizatidine at the standard dosages of 300 mg at bedtime. In 49 centres in Italy, all peptic ulcer patients aged over 65 years and with endoscopically documented acute disease were considered eligible for the study. Clinical check-ups were repeated every 3 weeks, while the endoscopic and biochemical assessments were scheduled at 6 and (in unhealed patients) 12 weeks.

STATISTICS

chi-squared test, Fisher's exact test, Student t-test for unpaired data. The study included 170 duodenal ulcer and 75 gastric ulcer patients. Of these, 83/170 duodenal ulcer and 38/75 gastric ulcer patients were treated with nizatidine 300 mg and the remainder with ranitidine 300 mg. The groups were well-matched for common clinical data. Eight patients dropped out. Healing rates at 6 and 12 weeks were 81.9% and 91.5% for nizatidine-treated duodenal ulcer patients versus 78.1% and 94.2% for ranitidine-treated duodenal ulcer cases (P: N.S.); 6 and 12-week healing rates were 76.3% and 89.5% for nizatidine-treated gastric ulcer patients versus 67.6% and 83.8% for ranitidine-treated gastric ulcer patients (P: N.S.). No slow healing risk factors were found. Only minor adverse events were registered.

IN CONCLUSION

ranitidine 300 mg and nizatidine 300 mg both proved effective and safe in the treatment of acute peptic ulceration in the elderly.

A controlled comparison of continuous ranitidine and intermittent famotidine infusions on gastric pH

Continuous infusions of any given H2-blocking drug have uniformly been found to be superior to intermittent infusions of the same H2-blocking drug in sustaining elevations in gastric pH. Comparisons of intermittent and continuous infusions among different H2-blocking drugs have heretofore not been made. Owing to its greater potency and longer half-life, the authors were interested in determining whether intermittent infusions of famotidine might be as effective as continuous infusions of ranitidine in sustaining elevations of gastric pH. The effectiveness of a continuous intravenous infusion of ranitidine (6.25 mg/hr) was compared with the effectiveness of intermittent intravenous infusions of famotidine (20 mg every 12 hours) in sustaining gastric pH above 4.0 in 18 young, healthy adult male subjects using a randomized two-way cross-over design. Gastric pH was continuously monitored for 24 hours. The intermittent famotidine regimen was determined to be as effective as the continuous ranitidine regimen with respect to the following parameters: (1) the percentage of the 24-hour dosing period during which gastric pH exceeded 4.0; (2) the area under the pH > or = 4 versus time curve; and (3) median gastric pH.