The effects of low doses of ranitidine on intragastric acidity in healthy men

Long-term management of gastroesophageal reflux disease with pantoprazole

Gastroesophageal reflux disease (GERD) is a chronic, relapsing disease that can progress to major complications. Affected patients have poorer health-related quality of life than the general population. As GERD requires continued therapy to prevent relapse and complications, most patients with erosive esophagitis require long-term acid suppressive treatment. Thus GERD results in a significant cost burden and poor health-related quality of life. The effective treatment of GERD provides symptom resolution and high rates of remission in erosive esophagitis, lowers the incidence of GERD complications, improves health-related quality of life, and reduces the cost of this disease. Proton pump inhibitors are accepted as the most effective initial and maintenance treatment for GERD. Oral pantoprazole is a safe, well tolerated and effective initial and maintenance treatment for patients with nonerosive GERD or erosive esophagitis. Oral pantoprazole has greater efficacy than histamine H(2)-receptor antagonists and generally similar efficacy to other proton pump inhibitors for the initial and maintenance treatment of GERD. In addition, oral pantoprazole has been shown to improve the quality of life of patients with GERD and is associated with high levels of patient satisfaction with therapy. GERD appears to be more common and more severe in the elderly, and pantoprazole has shown to be an effective treatment for this at-risk population.

Evidence-based assessment of the efficacy of esomeprazole for the healing of erosive esophagitis

Gastroesophageal reflux disease is generally a lifelong illness that affects many people. Erosive esophagitis can occur in up to 65% of patients with gastroesophageal reflux disease and more seriously, esophageal stricture, Barrett's esophagus and esophageal adenocarcinoma, can develop. The severity of symptoms is not a reliable indicator of the severity of erosive esophagitis and although endoscopy is the preferred method to diagnose and grade erosive esophagitis, its routine use is not practical. Therefore, early initiation of treatment with the most effective agent for treating this disease is a practical and logical strategy. Proton pump inhibitor therapy is preferred for the treatment of gastroesophageal reflux disease. This review provides a quantitative assessment of the efficacy of esomeprazole (Nexium, AstraZeneca), the most effective agent currently available.

Gastroesophageal Reflux Disease

Gastroesophageal reflux disease is a common, usually lifelong, disorder resulting from chronic abnormal exposure of the lower esophagus to gastric contents. Motor dysfunction of the lower esophageal sphincter is the primary cause of this disease. At this writing, no medical therapies can completely resolve abnormal lower esophageal sphincter function; therefore, the treatment of gastroesophageal reflux disease centers on suppression of intragastric acid secretion. Available acid-suppressant medications include proton pump inhibitors, H2-receptor antagonists, and antacids. Of these, the proton pump inhibitors are recognized generally as the mainstays of both short-term and long-term therapy for gastroesophageal reflux disease. All have a low incidence of side effects and are well tolerated by most patients. Five proton pump inhibitors are available currently for patients with gastroesophageal reflux disease. Of these, esomeprazole has shown greater efficacy in controlling intragastric acidity than the others. For patients with erosive esophagitis, esomeprazole has demonstrated higher healing rates and more rapid sustained resolution of heartburn than omeprazole or lansoprazole after up to 8 weeks of once-daily treatment. Because new therapies for gastroesophageal reflux disease are highly effective, patients can be reassured that their disease will be well controlled and their symptoms resolved with a safe and appropriate treatment.

Review article: treatment of mild and severe cases of GERD

GERD prevalence continues to rise in contrast to peptic ulcer disease. The spectrum contains reflux esophagitis and so-called 'endoscopy-negative GERD' or 'non-erosive GERD' (NERD) or S-GERD and patients with 'normal' overall 24-h esophageal acidification but with a high 'symptom-index'. The majority of reflux patients will not need endoscopy initially. Prompt referral for endoscopy is indicated only if the patient has atypical symptoms or alarm symptoms such as dysphagia, anemia, weight loss, severe abdominal pain, or pain that does not respond to acid neutralization or suppression, or develops symptoms after the age of 50 years. Antireflux therapy consist of raising the head of the bed, maintaining normal weight, and avoidance of foods and drugs that precipitate symptoms, together with antacids or over-the-counter H(2) receptor antagonists (H(2)RAs). If symptoms persist after these simple measures or if antacids or H(2)RAs are needed quite often, then a more formal first-line treatment should be started. Many experts feel that a stepdown approach instead of a stepup approach is clinically and economically a more appropriate way of installing such first-line therapy. Physicians increasingly consider prescribing a (low- or standard dose) once-a-day proton pump inhibitor (PPI) as firstline therapy. If symptoms recur after 4-week trial or are in sufficiently relieved, then the patient should be referred for endoscopy. Endoscopy may reveal no abnormalities (NERD) or evidence of reflux-induced damage. Treatment of endoscopy-negative reflux disease should be directed towards rapid relief of symptoms and then maintenance of relief using minimum effective therapy. Responses to PPIs are somewhat lower in endoscopy-negative patients compared to esophagitis. Some form of long-term therapy is needed in the majority of patients. 'On demand' PPI therapy to control reflux symptoms is a new and attractive option. The goal of treatment of GERD should be to relieve symptoms and to heal lesions. Symptom severity and much less endoscopic abnormalities, drives the therapy. When symptoms are mild or intermittent and when esophagitis is absent or minimal, standard dose PPI is usually reinstituted. If there is moderate or severe esophagitis or if symptoms are particularly troublesome, then the patient should start again with standard-dose PPI therapy once a day, but not uncommonly a b.i.d. dosage maybe necessary. Once a dose of the acid suppressant that relieves symptoms is found, this dose should be maintained for a period of 3 months. After this time, an attempt should be made to reduce the dose. A plan should be formulated for long-term treatment.

Determination of the time of onset of action of ranitidine and famotidine on intra-gastric acidity

BACKGROUND

No standard methods exist for determining the onset of action of gastric antisecretory agents in human subjects.

METHODS

Intragastric pH was measured when placebo, ranitidine 150 mg, ranitidine 75 mg or famotidine 10 mg were administered 30 min after the end of a meal.

RESULTS

When the onset of action was defined as the earliest time that mean gastric pH with active treatment was statistically significantly higher (P < 0.05) than the corresponding placebo value, the onsets of action of ranitidine 75 mg and 150 mg were 55 min, and of famotidine 10 mg, 90 min. When onset was defined in terms of a particular decrease in gastric acid concentration for the group as a whole or for individual subjects, there was an important variation in the relative times of onset of ranitidine 75 mg and famotidine 10 mg.

CONCLUSIONS

When administered after a meal, the onset of action of ranitidine and famotidine on gastric pH can be determined for individual subjects as well as for the group as a whole. When onset was determined for the group using statistical significance, which does not depend on arbitrary cut-off points, ranitidine 75 mg had an earlier onset of action than did famotidine 10 mg.

Ranitidine, 75 mg, over-the-counter dose: pharmacokinetic and pharmacodynamic effects in children with symptoms of gastro-oesophageal reflux

BACKGROUND

The use of over-the-counter antacids has increased in children under the age of 12 years, and has been followed by an apparent increase in the use of over-the-counter histamine-2 receptor antagonists. However, the pharmacokinetic and pharmacodynamic effects of over-the-counter histamine-2 receptor antagonists in the paediatric population are largely unknown.

AIM

To evaluate the pharmacokinetics and pharmacodynamics of a single dose of the over-the-counter histamine-2 receptor antagonist, ranitidine, 75 mg, in children with symptoms of gastro-oesophageal reflux disease.

METHODS

Children aged between 4 and 11 years with symptoms of heartburn suspected to be due to gastro-oesophageal reflux disease were recruited at six clinical centres. Following a single dose of either oral ranitidine, 75 mg (n=19), or placebo (n=10), recording of intragastric pH and serial blood sampling were carried out for 6 h.

RESULTS

The estimated pharmacokinetic parameters of ranitidine, 75 mg, were as follows: the median Cmax value of 477 ng/mL occurred within a median of 2.5 h after dosing, and the median half-life was 2.0 h. The intragastric pH began to rise approximately 30 min after dosing with ranitidine to a peak of pH; 4. The pH in the ranitidine group remained higher than that in the placebo group throughout the 6-h evaluation period. Adverse events were generally mild.

CONCLUSIONS

Ranitidine, 75 mg, significantly increased the intragastric pH in children aged 4-11 years. The pharmacokinetic and pharmacodynamic profiles were similar to those in adults. Ranitidine, 75 mg, appears to be effective for the control of intragastric acidity for 5-6 h in children aged 4-11 years.

A study of the nonprescription drug consumer's understanding of the ranitidine product label and actual product usage patterns in the treatment of episodic heartburn

INTRODUCTION

A study of the consumer's understanding of the product label instructions and the resulting product use were conducted to support the switch of a product from prescription to nonprescription status. H2 receptor antagonists have recently been approved for nonprescription use. This study evaluated the consumer's understanding of the product label for ranitidine hydrochloride (Zantac 75) and the product usage pattern in the treatment of episodic heartburn.

OBJECTIVES

Our objectives were to evaluate each aspect of the communication of labeled indications, contraindications, and directions for use of two label formats (old and new) for a new nonprescription preparation of ranitidine (Zantac) and to evaluate nonprescription consumers' use of ranitidine 75-mg tablets (as Zantac 75) in a medically unsupervised, at-home setting to observe whether these consumers used the product appropriately and followed directions as written on the package label.

METHODS

Adult male and female consumers (n = 1405) in a shopping mall environment who were attracted to a poster asking, "Do you have stomach problems?" were recruited for the label comprehension phase (two different label formats) and the 3-week usage phase if after reading the Zantac 75 package label they decided the product was appropriate for them. No instructions regarding the use of Zantac 75 were provided beyond what was printed on the package label. Subjects recorded use in a diary and tablet counts were performed at the end of the study period. A medical history was also taken at this time and an assessment of product use was performed by a physician.

RESULTS

In at least 84% of all subjects, both formats were effective in the communication of label objectives for the contraindication against concurrent prescription stomach ulcer medication, maximum daily dose, and maximum duration of dosing at maximum daily doses. The direction to take one tablet per dose was adhered to by 90% of consumers, and 90% of consumers followed the instructions to take no more than two tablets in 24 hours. Ninety-six percent of consumers complied with the direction not to take the maximum daily dose for more than 14 consecutive days. Notably, the maximum daily dose was taken for < or =3 consecutive days by 79% of consumers. The most frequently reported adverse events were headache, acute nasopharyngitis, upper respiratory tract infection, diarrhea, nausea, and menstrual cramps.

CONCLUSION

The study demonstrated that the vast majority of a large sample of unsupervised consumers understood the package label and fully complied with the package directions by not exceeding the maximum daily dosage and length of use. Nonprescription consumers safely used Zantac 75 without medical supervision.

Nonprescription doses of ranitidine are effective in the relief of episodic heartburn

BACKGROUND

Many Americans have heartburn or related symptoms monthly and >20% experience heartburn at least once per day. Although many self-treat episodic heartburn with nonprescription antacids, newer treatments that decrease gastric volume and increase the pH of refluxed material are proving effective and popular in relieving heartburn.

AIM

To evaluate the safety and efficacy of low-dose regimens of ranitidine for the relief of heartburn.

METHODS

Adults with at least a 3-month history of heartburn were eligible for this randomized, double-blind, parallel group, multicenter dose-ranging study. Following a 1-week, open-label run-in phase to document baseline heartburn frequency, subjects were randomly assigned to receive treatment with one tablet of either ranitidine, 75 mg (n = 537); ranitidine, 25 mg (n = 539); or placebo (n = 544), to be taken as needed up to four times daily for 2 weeks for the relief of heartburn.

RESULTS

The ranitidine 75-mg regimen was statistically (P < 0.05) and clinically (as defined a priori as > or =10% improvement) more effective than placebo in relieving episodic heartburn and in reducing antacid consumption. Ranitidine, 25 mg, was also statistically superior (P < 0.05) to placebo in providing heartburn relief. In addition, both regimens were superior to placebo in providing heartburn relief within 30 to 45 minutes of dosing. Ranitidine continued to be as effective over placebo in the treatment of the last heartburn episode as in the treatment of the first heartburn episode. Ranitidine was also equally effective over placebo in the treatment of mild, moderate, and severe episodes of heartburn. Ranitidine, 75 mg, was statistically superior to placebo for the relief of nocturnal heartburn episodes, whereas ranitidine, 25 mg, was not. All treatments were well tolerated and adverse events occurred no more frequently with the ranitidine regimens than with placebo.

CONCLUSIONS

Low-dose ranitidine provides prompt and lasting relief of heartburn and has a safety profile comparable to that of placebo.

Synergy between low-dose ranitidine and antacid in decreasing gastric and oesophageal acidity and relieving meal-induced heartburn

BACKGROUND

The pathophysiology of recurrent postprandial heartburn and the basis for the effectiveness of antacids or low doses of histamine H2-receptor antagonists have not been well studied.

METHODS

The selected subjects (n=26) had heartburn more than four times a week for at least 2 months, which was responsive to antacids. Gastric pH and oesophageal pH were measured for 1 h before, during, and 4.5 h after ingestion of a meal over 0.5 h. Heartburn severity was assessed at 15-min intervals beginning at the end of the meal. Each subject randomly received placebo, 75 mg ranitidine, 420 mg calcium carbonate, and ranitidine plus calcium carbonate. Values for pH were converted to acid concentration (mM) and integrated acidity was calculated from the cumulative, time-weighted means of the acid concentrations for every second of the postprandial recording period.

RESULTS

There was a close temporal relationship between heartburn and oesophageal acidity. Most oesophageal acid exposure occurred over a 90-min period that began approximately 45 min after the end of the meal. During this period the gastric acid concentration was less than 5% of maximal. Ranitidine significantly decreased gastric but not oesophageal acidity, whilst antacid significantly decreased oesophageal but not gastric acidity. Ranitidine plus antacid significantly decreased both gastric and oesophageal acidity. Antacid alone and ranitidine plus antacid significantly decreased heartburn severity.

CONCLUSIONS

Determining integrated gastric and oesophageal acidity provides novel information regarding the pathophysiology of meal-induced heartburn as well as the actions of low-dose ranitidine and antacid. For subjects with meal-induced heartburn, treatment with low-dose ranitidine plus antacid is particularly effective in decreasing gastric and oesophageal acidity as well as heartburn severity.

Pharmacological and pharmacodynamic essentials of H(2)-receptor antagonists and proton pump inhibitors for the practising physician

The suppression of gastric acid secretion with anti-secretory agents has been the mainstay of medical treatment for patients with acid-related disorders. Although the majority of Helicobacter pylori -related peptic ulcers can be healed with antibiotics, ulcer healing and symptom control can be significantly improved when antibiotics are given with anti-secretory agents, especially with a proton pump inhibitor. There is a dynamic relationship between the suppression of intragastric acidity and the healing of peptic ulcer and erosive oesophagitis and control of acid-related symptoms. The suppression of gastric acid secretion achieved with H(2)-receptor antagonists has, however, proved to be suboptimal for effectively controlling acid-related disorders, especially for healing erosive oesophagitis and for the relief of reflux symptoms. H(2)-receptor antagonists are also not effective in inhibiting meal-stimulated acid secretion, which is required for managing patients with erosive oesophagitis. Furthermore, the rapid development of tolerance to H(2)-receptor antagonists and the rebound acid hypersecretion after the withdrawal of an H(2)-receptor antagonist further limit their clinical use. Although low-dose H(2)-receptor antagonists are currently available as over-the-counter medications for self-controlling acid-related symptoms, their pharmacology and pharmacodynamics have not been well studied, especially in the self-medicating population. Proton pump inhibitors have been proved to be very effective for suppressing intragastric acidity to all known stimuli, although variations exist in the rapidity of onset of action and the potency of acid inhibition after oral administration at the approved therapeutic doses, which may have important clinical implications for the treatment of gastro-oesophageal reflux disease and perhaps for eradicating H. pylori infection when a proton pump inhibitor is given with antibiotics. Once-daily dosing in the morning is more effective than dosing in the evening for all proton pump inhibitors with respect to the suppression of intragastric acidity and daytime gastric acid secretion in particular, which may result from a better bio-availability being achieved with the morning dose. When higher doses are needed, these drugs must be given twice daily to achieve the optimal suppression of 24 hour intragastric acidity. Preliminary results have shown that esomeprazole, the optical isomer of omeprazole, given at 40 mg, is significantly more effective than omeprazole 40 mg, lansoprazole 30 mg or pantoprazole 40 mg for suppressing gastric acid secretion. However, more studies in different patient populations are needed to compare esomeprazole with the existing proton pump inhibitors with regard to their efficacy, cost-effectiveness and long-term safety for the management of acid-related disorders.

A double-blind, placebo-controlled study of the efficacy and safety of non-prescription ranitidine 75 mg in the prevention of meal-induced heartburn

BACKGROUND

Ranitidine 75 mg (Zantac 75) has been shown to be effective for the treatment of pre-existing heartburn symptoms.

AIM

To compare the efficacy of dosing ranitidine 75 mg or placebo 30 min prior to a proven heartburn-provoking meal in completely preventing or reducing subsequent heartburn symptoms.

METHODS

A randomized, double-blind, parallel methodology was used at nine investigative centres. Following a screening visit, patients ate a standard test meal consisting of chili, chips and a soft drink on two occasions. On the first occasion, patients received single-blind placebo 30 min before the meal. This meal was used to qualify patients and to ensure the onset of a minimum level of heartburn. Patients who qualified were randomized (n = 284) to receive double-blind ranitidine 75 mg or placebo 30 min before a second test meal administered 4-14 days later at the treatment visit. Patients recorded whether heartburn was present and rated heartburn severity by completing visual analogue scales at 15-min intervals over the 4. 5 h meal evaluation periods.

RESULTS

Statistically significant differences favouring ranitidine 75 mg were determined for complete prevention of heartburn (P < 0.006), heartburn severity area under the curve (P < 0.001), a clinical success end-point (P < 0.001), and all other end-points (P < 0.001).

CONCLUSIONS

These data clearly demonstrate that ranitidine 75 mg is effective in completely preventing or decreasing heartburn when administered 30 min prior to a provocative meal.

Low-dose ranitidine for the relief of heartburn

BACKGROUND

Approximately 30% of adults in the USA suffer from heartburn or related symptoms monthly; more than 20% of these sufferers experience heartburn at least once per day. Although many rely on self-medication with antacids for the relief of their symptoms, treatments that decrease gastric volume as well as increase the pH of refluxed material should be more effective in relieving heartburn.

AIM

To compare the safety and efficacy of low-dose regimens of ranitidine for the relief of heartburn.

METHODS

Adults with at least a 3-month history of heartburn were eligible for this randomized, double-blind, parallel group, multicentre dose-ranging study. Following a 1-week open-label run-in phase to document baseline heartburn frequency, subjects were randomized to receive treatment with one tablet of either ranitidine 75 mg (n = 491), ranitidine 25 mg (n = 504), or placebo (n = 494), to be taken as needed up to four times daily for 2 weeks for the relief of heartburn.

RESULTS

The ranitidine 75 mg regimen was clinically (> 10 percentage points) and statistically (P < 0.05) significantly more effective than placebo for all measured efficacy end-points in relieving heartburn and reducing antacid consumption. In addition, the ranitidine 75 mg regimen was superior to placebo in providing heartburn relief within 30 min of dosing that lasted for up to 12 h. Ranitidine 25 mg was observed to be statistically superior (P < 0.05) but not clinically different from placebo, as defined a priori, in providing heartburn relief. All treatments were well tolerated and adverse events occurred no more frequently with the ranitidine regimens than with placebo.

CONCLUSIONS

Ranitidine 75 mg provides prompt relief of heartburn that lasts for up to 12 h and has a safety profile comparable to that of placebo.

An evaluation of increasing doses of ranitidine for treatment of heartburn

BACKGROUND

This was a randomized, double-blind, placebo-controlled, multicentre, parallel group, dose-ranging trial of ranitidine tablets for relief of episodic heartburn. Adult out-patients who reported heartburn relieved by antacids at least seven times per week were eligible.

METHODS

Patients who successfully completed a 1-week single-blind placebo run-in phase and who did not achieve adequate relief in more than 50% of heartburn episodes were randomized to a 1-week, double-blind treatment phase during which they received ranitidine doses of 25, 75 or 125 mg, or placebo.

RESULTS

Of 577 patients randomized, 566 had at least one evaluable heartburn episode and were included in the intention-to-treat analysis. All three ranitidine doses were statistically significantly superior to placebo in providing overall episodic heartburn relief for the first episode (P < 0.002), last episode (P</=0.004), and all episodes combined (P < 0.001). The ranitidine 75 mg and 125 mg doses provided sustained relief (relief within 60 min of dosing that lasted throughout the 4-h evaluation period) to a greater proportion of patients for each individual episode (43-56% for 75 mg and 42-57% for 125 mg) than the ranitidine 25 mg dose (35-50%) or placebo (21-29%). The incidence of adverse events was similar in all treatment groups.

CONCLUSIONS

All three ranitidine doses (125, 75 and 25 mg) are safe and superior to placebo in providing adequate relief for heartburn. Ranitidine's onset of relief was progressive and clearly present by 30 min as shown by statistically significant differences for the 75 mg dose when compared to placebo. Similarly, patients treated with ranitidine 75 mg and 125 mg consumed statistically fewer rescue antacids than placebo-treated patients for the first episode. All three doses were well tolerated, with adverse event profiles similar to those of placebo.

Effects of tablet and effervescent formulations of ranitidine 75 mg and cimetidine 200 mg on gastric acidity and oesophageal acid exposure in healthy humans

BACKGROUND

Because of their tolerance and safety, low doses of H2-receptor antagonists are now increasingly used in some countries for self-care medication of gastro-oesophageal reflux symptoms.

AIM

The purpose of this randomized, double-blind, placebo-controlled, five-way crossover study was to determine and to compare the effects of low doses of ranitidine and cimetidine both on gastric pH and on oesophageal acid exposure.

METHODS

Gastric and oesophageal pH were simultaneously monitored in 20 healthy subjects using two glass pH electrodes, after placebo and single doses of ranitidine 75 mg and cimetidine 200 mg (effervescent and tablet forms), for 4 h before and after a meal.

RESULTS

During the fasting period, median gastric pH rose significantly with both drugs, but more rapidly with the effervescent forms; the oesophageal acid exposure was significantly decreased by all drug regimens. After the meal, although there was no significant difference in gastric pH values, oesophageal acid exposure was significantly decreased in comparison with placebo with both forms of ranitidine (P < 0.05), and also for ranitidine tablets in comparison with cimetidine tablets (P < 0.05).

CONCLUSIONS

Low doses of ranitidine and cimetidine increase gastric pH, with a more pronounced effect for ranitidine. Effervescent formulations of both drugs induce a slightly more rapid initial increase in pH than tablets. Ranitidine demonstrates a more prolonged effect than cimetidine and decreases oesophageal acid exposure monitored after a meal ingested 4 h after the drug intake.