Comparative efficacy of acid reflux inhibition by drug therapy in reflux esophagitis

The Effect of H2 Receptor Antagonist in Acid Inhibition and Its Clinical Efficacy

The first histamine H₂ receptor antagonists (H₂RAs) were developed in the early 1970s. They played a dominant role in treating peptic ulcer disease and gastroesophageal reflux disease (GERD). H₂RAs block the production of acid by H⁺, K⁺-ATPase at the parietal cells and produce gastric luminal anacidity for varying periods. H₂RAs are highly selective, and they do not affect H1 receptors. Moreover, they are not anticholinergic agents. Sequential development of H₂RAs, proton pump inhibitors (PPIs), and discovery of Helicobacter pylori infection changed the paradigm of peptic ulcer disease with marked decrease of morbidity and mortality. PPIs are known to be the most effective drugs that are currently available for suppressing gastric acid secretion. Many studies have shown its superiority over H₂RAs as a treatment for acid-related disorders, such as peptic ulcer disease, GERD, and Zollinger-Ellison syndrome. However, other studies have reported that PPIs may not be able to render stomach achlorhydric and have identified a phenomenon of increasing gastric acidity at night in individuals receiving a PPI twice daily. These nocturnal acid breakthrough episodes can be eliminated with an addition of H₂RAs at night. The effectiveness of nighttime dose of H₂RA suggests a major role of histamine in nocturnal acid secretion. H₂RAs reduce secretion of gastric acid, and each H₂RA also has specific effects. For instance, nizitidine alleviates not only symptoms of GERD, but also provokes gastric emptying, resulting in clinical symptom improvement of functional dyspepsia. The aim of this paper was to review the characteristics and role of H₂RAs and assess the future strategy and treatment of upper gastrointestinal disease, including acid related disorders.

Effect of omeprazole and domperidone on adult asthmatics with gastroesophageal reflux

AIM: To study the effect of combined omeprazole (Ome) and domperidone (Dom) therapy on asthma symptoms and pulmonary function in asthmatics with gastroesophageal reflux.

METHODS: We selected 198 asthmatics with gastroesophageal reflux diagnosed by 24-h esophageal pH monitoring to receive Ome 20 mg twice daily and Dom 10 mg three times daily or placebo for 16 wk (1:1 double-blind randomization). Spirometry was done at baseline and after 16 wk of treatment. The primary outcome measures were: mean daily daytime and nighttime asthma symptom scores. Mean daily reflux symptom scores, albuterol use as rescue medication (number of puffs), daytime and nighttime peak expiratory flow rate (PEFR), postbronchodilator forced expiratory volume in 1 second (FEV₁) and postbronchodilator forced vital capacity (FVC) were secondary outcome measures.

RESULTS: Comparison of mean change from baseline between antireflux therapy and placebo groups revealed significant reduction in daytime asthma symptom score (17.4% vs 8.9%), nighttime asthma symptom score (19.6% vs 5.4%), reflux symptom score (8.7% vs 1.6%) and rescue medication use (23.2% vs 3.1%) after antireflux therapy compared to mean change in placebo group (P < 0.001). There was significant improvement in morning PEFR (7.9% vs 0.2%), evening PEFR (9.8% vs 0.5%), FEV₁ (11.1% vs 3.78%) and FVC (9.3% vs 1.52%) in the antireflux therapy group compared to placebo on comparing the mean change from baseline after 16 wk (P < 0.01).

CONCLUSION: Combined therapy with Ome and Dom in adult asthmatics with gastroesophageal reflux may be beneficial by reducing asthma symptoms, rescuing medication use, and improving pulmonary function.

Comparative study of nizatidine and famotidine for maintenance therapy of erosive esophagitis

BACKGROUND

The therapeutic effect of combined administration of prokinetics and histamine H2 receptor antagonists (H2RA) in gastroesophageal reflux disease is reported to be superior to that of monotherapy with H2RA alone. In addition to its acid-suppressing effect, the H2RA nizatidine also has a prokinetic action by suppressing acetylcholine esterase. The present multicenter, randomized controlled study was performed to investigate whether nizatidine is superior to famotidine, which does not suppress acetylcholine esterase activity, in maintenance therapy for erosive esophagitis. In addition, the question as to whether the grade of erosive esophagitis affects the non-recurrence rate during the maintenance therapy with H2RA was also investigated.

METHODS

Seventy-two patients with endoscopically healed erosive esophagitis after 8 weeks of initial treatment with proton pump inhibitors were randomly divided into two groups. Patients in the nizatidine group were treated with 150 mg nizatidine twice a day (b.i.d.), while patients in the famotidine group were treated with 20 mg famotidine b.i.d. for 6 months. At the end of therapy, and at the time when patients complained of symptoms, endoscopic investigations were repeated to find out whether the esophagitis had recurred.

RESULTS

Nizatidine produced a significantly higher non-recurrence rate than famotidine (P = 0.049 in intention-to-treat [ITT] analysis). This difference of remission rate between nizatidine and famotidine was observed mainly in grade B esophagitis (P = 0.016 in ITT analysis).

CONCLUSION

Nizatidine is a more effective H2RA than famotidine in the maintenance therapy of patients with reflux esophagitis.

Randomized comparative study of omeprazole and famotidine in reflux esophagitis

BACKGROUND

Although proton pump inhibitors (PPI) and H2-receptor antagonists (H2-RA) are routinely used in the treatment of reflux esophagitis (RE), no consensus has been reached yet as to whether the first-choice drug should be PPI or H2-RA. In this study, the effects of omeprazole (OMP) and famotidine (FAM) on RE have been examined in a randomized comparative study.

METHODS

Protocols of OMP 20 mg once daily or FAM 20 mg twice daily for 8 weeks were allocated to 56 cases with RE at random, using an envelope randomization method. Their efficacy in achieving healing was examined endoscopically and a relief from subjective symptoms was compared.

RESULTS

Patient's background such as sex, age, recurrence, hiatal hernia, smoking and drinking habits, and complications, and the severity of esophagitis at the time of enrolment were not significantly different between the two groups. Healing in the OMP group and the FAM group was observed in 72 and 32% (P = 0.025) of patients at week 4 and 95 and 53% (P = 0.003) of patients at week 8, respectively. Subjective symptoms were relieved more frequently in the OMP group (at week 2, 67% compared with 29%, P = 0.005; at week 4, 95% compared with 55%, P = 0.009), but this superiority was not significant at week 8 (94% compared with 65%, P = 0.085). No serious adverse events occurred.

CONCLUSIONS

Omeprazole provided quicker healing and a greater relief from subjective symptoms than did FAM in the treatment of RE, and was considered more suitable as a first-choice drug.

Comparative role of omeprazole in the treatment of gastroesophageal reflux disease

OBJECTIVE

To review gastroesophageal reflux disease (GERD) and its treatment, with emphasis on the use and place of omeprazole, a proton pump inhibitor.

DATA SOURCES

A compilation prepared by the National Library of Medicine's Interactive Retrieval Services (Medlars II) for the period 1987 to 1994 was used as the data source.

STUDY SELECTION

Focus was placed on human comparative clinical studies with well-accepted measures of esophageal healing (endoscopy) and symptom resolution. Safety data were compiled from the clinical trials literature and large postmarketing data studies. Pharmacoeconomic studies selected were judged to meet the criteria of good design, presence of sensitivity testing, and statement of perspective.

DATA EXTRACTION

Data were obtained from double-blind, controlled clinical studies. Other data were extracted from pertinent literature of good design and significant results.

DATA SYNTHESIS

Overall, the clinical trials of omeprazole for the treatment of patients with erosive GERD demonstrate that omeprazole provides superior therapy in terms of esophageal healing symptom resolution and patient compliance when compared with histamine2-receptor antagonists (H2RAs) and antacids. In addition, studies also indicate that omeprazole is the most effective agent for the treatment of patients with GERD refractory to other treatments. Dosage adjustment is not necessary in patients with impaired renal or hepatic function or in the elderly. Finally, although the acquisition drug cost for daily treatment of patients with GERD is highest with the use of omeprazole, pharmacoeconomic studies indicate that treatment is more cost-effective with the use of omeprazole than with H2RA or antacid treatment alone or combined with nonpharmacologic approaches.

CONCLUSIONS

Based on efficacy, safety, and cost-effectiveness, omeprazole is the drug of choice for the treatment of patients with endoscopically confirmed erosive GERD.

Cisapride. An updated review of its pharmacology and therapeutic efficacy as a prokinetic agent in gastrointestinal motility disorders

Cisapride is an orally administered prokinetic agent which facilitates or restores motility throughout the length of the gastrointestinal tract. It is a substituted piperidinyl benzamide, chemically related to metoclopramide, but unlike metoclopramide, cisapride is largely devoid of central depressant or antidopaminergic effects. In placebo-controlled trials, cisapride improved healing rates and symptoms in both adults and children with reflux oesophagitis. Maintenance therapy with cisapride at half the healing dose is effective in reducing the incidence of relapse. Symptoms are also alleviated in patients with functional dyspepsia, and gastric emptying and symptoms are improved in most patients with gastroparesis, an effect which is sustained during long term administration. However, the efficacy of cisapride in end-stage gastroparesis remains less clear. Cisapride increases stool frequency in patients with chronic constipation, and limited data suggest that the drug may also be beneficial in treating chronic intestinal pseudo-obstruction and irritable bowel syndrome. Cisapride demonstrated efficacy comparable with or superior to that of metoclopramide, and was at least as effective as cimetidine and ranitidine in patients with reflux disease. In patients with functional dyspepsia, cisapride has shown at least equal efficacy to domperidone, metoclopramide and ranitidine, and superior efficacy to cimetidine in the small comparative trials conducted to date. Adverse effects in patients receiving cisapride are generally transient and mild, with abdominal cramping, borborygmi, diarrhoea or loose stools most frequently reported. Central nervous system adverse effects are rare. Thus, with its favourable tolerability profile and demonstrated efficacy in a variety of gastrointestinal motility disorders, the position of cisapride as a valuable agent in the management of patients with gastrointestinal motility disorders is strengthening. However, larger well-controlled comparative trials of the drug with other agents are necessary before the relative position of cisapride in therapy can be categorically defined.