A single dose of ranitidine 150 mg modulates oesophageal acid sensitivity in patients with functional heartburn

BACKGROUND

The rapid onset and symptomatic response to histamine-2 receptor antagonists prior to the pharmacological effect on acid secretion suggests a different mechanism of action.

AIM

To determine if ranitidine decreases oesophageal sensitivity to chemical and mechanical stimulation, potentially via oesophageal histamine receptors.

METHODS

A total of 18 patients with functional heartburn received oral ranitidine 150 mg b.d. or placebo for 7 consecutive days in a double-blind randomized crossover design and underwent Barostat balloon distention and Bernstein acid infusion on study day 1 (90 min postdose) and study day 7. First sensation and pain were recorded and pain severity was rated on a 5-point Likert scale and a 100 mm visual analogue scale. Least square mean values were generated and one-tailed t-tests were performed.

RESULTS

After a single dose of ranitidine 150 mg, time to pain with oesophageal acid infusion was increased by 29% (P < 0.05) and visual analogue scale and Likert scores were decreased by 20% (P < 0.06) and 23% (P < 0.02), respectively compared with placebo. After 1 week of ranitidine, positive alterations in sensory parameters persisted. Balloon distention sensory parameters were not altered by ranitidine.

CONCLUSIONS

Ranitidine significantly decreased oesophageal sensitivity to acid. Failure of ranitidine to improve balloon sensory parameters supports existence of multiple sensory pathways in the oesophagus.

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.

Effects of antacid formulation on postprandial oesophageal acidity in patients with a history of episodic heartburn

BACKGROUND

Heartburn self-treatment with antacids is extremely common. If the oesophagus is the primary site of antacid action, chewable antacids might raise the oesophageal pH more effectively than swallowable tablets.

AIM

To establish a model to assess postprandial acid reflux and to compare the onset and duration of action on oesophageal pH of different antacid formulations.

METHODS

Twenty subjects with a history of episodic heartburn underwent eight pH monitoring sessions each for 5.5 h postprandially. One hour after consuming a meal consisting of chili, cheese, raw onions and cola, subjects received 750 mg, 1500 mg and 3000 mg of either chewable or swallowable CaCO3 tablets, an effervescent bicarbonate solution or placebo. Oesophageal and gastric pH data were collected.

RESULTS

Mean intra-oesophageal pH remained lower than baseline for more than 1 h (pH range 5-5.5) postprandially, indicating reflux of somewhat acidic intragastric contents into the oesophagus. The onset of action on oesophageal pH was similar for all antacids (30-35 min). The duration of action on pH varied: chewable tablets and effervescent bicarbonate had relatively long durations of action (oesophagus, 40-45 min; stomach, 100-180 min); swallowable tablets had little effect.

CONCLUSIONS

The meal model used in this study dependably produced acidic gastro-oesophageal reflux. Antacids increased oesophageal pH independent of gastric pH, demonstrating that chewing antacids controls oesophageal acidity more effectively than swallowing antacid tablets.

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.

Managing heartburn at the 'base' of the GERD 'iceberg': effervescent ranitidine 150 mg b.d. provides faster and better heartburn relief than antacids

BACKGROUND

Many individuals with heartburn self-medicate with antacids for relief of their symptoms.

AIM

To compare efficacy of effervescent ranitidine to as-needed calcium carbonate antacids in subjects who self-treat heartburn.

METHODS

A total of 155 subjects with frequent antacid-responsive heartburn were randomized to receive effervescent ranitidine 150 mg tablets b.d., or as-needed calcium carbonate 750 mg for 12 weeks. Endoscopic oesophagitis severity and mucosal histology were assessed at baseline, and at weeks 6 and 12. Heartburn frequency, severity, and antacid consumption were recorded daily, and quality of life was assessed at baseline, and at weeks 6 and 12.

RESULTS

Heartburn frequency and severity were significantly decreased after 1 day of ranitidine (P < 0.02). By week 6, ranitidine had significantly decreased rescue antacid consumption (7.3 tablets, P < 0.001) vs. antacids (14.1 tablets). Endoscopic oesophagitis healing (</= grade 1) was significantly better with ranitidine (55%, P=0.022) vs. antacids (29%). Quality of life was improved by both treatments; however, ranitidine was numerically superior for all quality of life parameters, statistically superior for several quality of life indices at week 6 and for the pain-related index by week 12 (P < 0. 05).

CONCLUSIONS

For subjects self-administering antacids for chronic heartburn, effervescent ranitidine 150 mg b.d. is more effective than antacids in reducing heartburn, healing erosive oesophagitis, alleviating pain, and improving quality of life.

Helicobacter pylori infection rates in duodenal ulcer patients in the United States may be lower than previously estimated

OBJECTIVE

Published studies have estimated the rate of Helicobacter pylori (H. pylori) infection in patients with duodenal ulcer disease to be as high as 95%; the majority of remaining duodenal ulcers have been attributed to the use of ulcerogenic drugs such as nonsteroidal antiinflammatory drugs (NSAIDs). We aimed to assess the H. pylori prevalence rates of U.S. duodenal ulcer patients in large, well-controlled studies.

METHODS

More than 2900 patients with endoscopically diagnosed non-NSAID duodenal ulcers were enrolled in a series of six placebo-controlled, double-blind studies conducted in the United States that assessed H. pylori using a combination of tests. Patients were considered infected with H. pylori only if culture growth was observed, or both histological and CLOtest results were positive. Patients were considered uninfected if the results of at least two tests were negative. Patients with missing test results, results of only a single test, or conflicting test results were not evaluable for H. pylori assessment.

RESULTS

Of the 2394 endoscopically diagnosed evaluable duodenal ulcer patients, 73% (1737) were confirmed infected with H. pylori at study entry.

CONCLUSIONS

The results of six carefully designed and controlled studies suggest that an assumed H. pylori infection rate of approximately 95% may overestimate the actual rate of H. pylori infection in duodenal ulcer patients in the United States. Although H. pylori infection is an important factor in the etiology of noniatrogenic duodenal ulcer disease, other factors may predominate in some patients and should not be overlooked in determining an appropriate course of treatment. The empiric use of antibiotic therapy for ulcer patients without confirmation of the presence of H. pylori cannot be recommended.

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.

Ranitidine bismuth citrate plus clarithromycin: a dual therapy regimen for patients with duodenal ulcer

BACKGROUND

The combination of ranitidine bismuth citrate (RBC) and clarithromycin (CLR) was compared with each treatment alone for the eradication of H. pylori and healing of duodenal ulcers in patients infected with H. pylori.

METHODS

This two-phase, randomized, double-blind, placebo-controlled, multicenter study evaluated 203 patients with an active duodenal ulcer treated with either (1) RBC 400 mg BID for 4 weeks plus CLR 500 mg TID for the first 2 weeks; (2) RBC 400 mg BID for 4 weeks plus placebo TID for the first 2 weeks; (3) placebo BID for 4 weeks plus CLR 500 mg TID for the first 2 weeks; or (4) placebo BID for 4 weeks plus placebo TID for the first 2 weeks. Patients with healed ulcers after treatment entered a 24-week observation phase for the assessment of H. pylori and ulcer relapse.

RESULTS

Four-week ulcer healing rates were higher with RBC + CLR (71%) and RBC alone (66%) compared with placebo (15%; p < 0.05) and CLR alone (49%). H. pylori eradication rates were significantly higher with RBC + CLR (86%) compared with RBC alone (0%, p < .001) or CLR alone (24%, p < .001). Ulcer recurrence rates after 6 months were lower in patients eradicated of H. pylori infection (17%) compared with patients who remained infected (43%). All treatments were well tolerated.

CONCLUSIONS

Ranitidine bismuth citrate plus clarithromycin is a simple, convenient, and well-tolerated dual therapy regimen that is effective in eradicating H. pylori and healing duodenal ulcers in patients infected with H. pylori. The eradication of H. pylori in patients with healed ulcers significantly reduces the rate of ulcer relapse.

An alternative non-macrolide, non-imidazole treatment regimen for curing Helicobacter pylori and duodenal ulcers: ranitidine bismuth citrate plus amoxicillin. The RBC H. pylori Study Group

BACKGROUND

Because patients who fail to be cured of H. pylori infection following macrolide or imidazole therapy are difficult to treat, there is a clear need for a reasonably effective and simple second-line treatment regimen. The purpose of these two studies was to evaluate the efficacy of ranitidine bismuth citrate (RBC) plus amoxicillin for the cure of H. pylori infection and for healing duodenal ulcers and preventing ulcer relapse.

MATERIALS AND METHODS

Two identically designed randomized, double-blind, double-dummy studies were conducted in patients with an H. pylori-associated duodenal ulcer. Patients were treated with either RBC 400 mg bid for 4 weeks plus amoxicillin 500 mg qid for 2 weeks, RBC 400 mg bid for 4 weeks and placebo qid for 2 weeks, placebo bid for 4 weeks and amoxicillin 500 mg qid for 2 weeks, or placebo bid for 4 weeks and placebo qid for 2 weeks. Patients with healed ulcers after 4 weeks of treatment were eligible for entry into a 24-week observation phase for the assessment of H. pylori status (culture, histology, and CLOtest) and ulcer relapse.

RESULTS

A total of 229 patients with confirmed H. pylori infection at baseline were evaluated. Of these, 132 whose ulcers had healed entered the 24-week posttreatment observation phase. The combination of RBC plus amoxicillin resulted in higher H. pylori cure rates (55%) and higher duodenal ulcer healing (74%) than did either treatment alone. All treatment were well tolerated.

CONCLUSIONS

The combination of ranitidine bismuth citrate plus amoxicillin cures H. pylori infection in more than half of the patients treated. This treatment regimen shows promise as the basis for future non-macrolide, non-imidazole triple therapy regimens for curing H. pylori infection. Such regimens may be appropriate second-line treatment for patients who are resistant to or who are unable to tolerate macrolide- or imidazole-containing therapies.

Effects of ranitidine bismuth citrate on gastric acid secretion and gastrin release in subjects with and without Helicobacter pylori infection

BACKGROUND

Ranitidine bismuth citrate is a novel antiulcerant that provides the antisecretory activity of ranitidine and the gastric mucosal protection and antibacterial properties of bismuth.

METHODS

This randomized, double-blind, placebo-controlled study evaluated the effects of single doses of ranitidine bismuth citrate 200 mg, 400 mg and 800 mg and ranitidine hydrochloride 150 mg on gastrin release and suppression of gastric acid secretion, and compared acid secretory profiles and gastrin release between Helicobacter pylori-negative and -positive patients. Plasma gastrin concentrations were determined by radioimmunoassay under basal conditions and in response to peptone meal stimulation. Acid secretion was measured under basal conditions and in response to peptone meal stimulation. Presence of H. pylori was determined by both 14C-urea breath test and ELISA serology.

RESULTS

Inhibition of gastric acid output by ranitidine bismuth citrate was both time- and dose-dependent over the 9-h post-dose study period. Doses of ranitidine bismuth citrate 400 mg and ranitidine hydrochloride 150 mg, which are equimolar, produced similar suppression of acid output regardless of H. pylori status. Ranitidine bismuth citrate had no effect on plasma gastrin concentrations regardless of H. pylori status. All doses of ranitidine bismuth citrate were well tolerated.

CONCLUSIONS

Ranitidine bismuth citrate caused time- and dose-dependent reductions in meal-stimulated and between-meal gastric acid output regardless of H. pylori status. The magnitude of decreased acid secretion was similar with ranitidine bismuth citrate 400 mg and ranitidine hydrochloride 150 mg. Ranitidine bismuth citrate had no effect on plasma gastrin concentrations.

Ranitidine bismuth citrate plus clarithromycin is effective for healing duodenal ulcers, eradicating H. pylori and reducing ulcer recurrence. RBC H. pylori Study Group

AIM

To compare the efficacy of the coadministration of ranitidine bismuth citrate plus the antibiotic clarithromycin, with ranitidine bismuth citrate alone or clarithromycin alone for the healing of duodenal ulcers, eradication of H. pylori and the reduction of ulcer recurrence.

METHODS

This two-phase, randomized, double-blind, placebo-controlled, multicentre study consisted of a 4-week treatment phase followed by a 24-week post-treatment observation phase. Patients with an active duodenal ulcer were treated with either ranitidine bismuth citrate 400 mg b.d. for 4 weeks plus clarithromycin 500 mg t.d.s. for the first 2 weeks; ranitidine bismuth citrate 400 mg b.d. for 4 weeks plus placebo t.d.s. for first 2 weeks; placebo b.d. for 4 weeks plus clarithromycin 500 mg t.d.s. for the first 2 weeks; or placebo b.d. for 4 weeks plus placebo t.d.s. for the first 2 weeks.

RESULTS

Ulcer healing rates after 4 weeks of treatment were highest with ranitidine bismuth citrate plus clarithromycin (82%) followed by ranitidine bismuth citrate alone (74%; P = 0.373), clarithromycin alone (73%; P = 0.33) and placebo (52%; P = 0.007). Ranitidine bismuth citrate plus clarithromycin provided significantly better ulcer symptom relief compared with clarithromycin alone or placebo (P < 0.05). The coadministration of ranitidine bismuth citrate plus clarithromycin resulted in significantly higher H. pylori eradication rates 4 weeks post-treatment (82%) than did treatment with either ranitidine bismuth citrate alone (0%; P < 0.001), clarithromycin alone (36%; P = 0.008) or placebo (0%; P < 0.001). Ulcer recurrence rates 24 weeks post-treatment were lower following treatment with ranitidine bismuth citrate plus clarithromycin (21%) compared with ranitidine bismuth citrate alone (86%; P < 0.001), clarithromycin alone (40%; P = 0.062) or placebo (88%; P = 0.006). All treatments were well tolerated.

CONCLUSIONS

The coadministration of ranitidine bismuth citrate plus clarithromycin is a simple, well-tolerated and effective treatment for active H. pylori-associated duodenal ulcer disease. This treatment regimen effectively heals duodenal ulcers, provides effective symptom relief, eradicates H. pylori infection and reduces the rate of ulcer recurrence. The eradication of H. pylori infection in patients with recently healed duodenal ulcers is associated with a significant reduction in the rate of ulcer recurrence.

Dual and triple therapy regimens of antisecretory agents and antibiotics for the eradication of Helicobacter pylori: an overview

BACKGROUND

Studies evaluating therapeutic regimens that combine antisecretory agents with antibiotics for the eradication of H. pylori have reported significant variations in efficacy.

METHODS

We reviewed the published literature to compare H. pylori eradication rates in patients treated with either omeprazole, ranitidine bismuth citrate (RBC), or ranitidine plus metronidazole combined with either amoxicillin or clarithromycin.

RESULTS

Wide variations in H. pylori eradication rates have been reported with omeprazole plus either amoxicillin (0-100%) or clarithromycin (42-88%). Eradication rates ranging from 45% to 89% and from 74% to 94% have been reported with RBC plus either amoxicillin or clarithromycin, respectively. Eradication rates ranging from 48% to 90% have been reported with ranitidine plus metronidazole and amoxicillin and one study reported an eradication rate of 95% with ranitidine plus metronidazole and clarithromycin

CONCLUSIONS

Well-controlled trials with ranitidine bismuth citrate plus clarithromycin suggest that this combination may provide the most consistent and effective regimen for the eradication of H. pylori infection.

Effect of administration of ranitidine bismuth citrate with food on the suppression and eradication of Helicobacter pylori in infected volunteers

OBJECTIVE

This study examined the effect of administration with food on the ability of ranitidine bismuth citrate to suppress and eradicate Helicobacter pylori in 41 infected volunteers.

RESULTS

After a 7-day course of treatment with ranitidine bismuth citrate (400 mg b.i.d.), 90% (18/20) of subjects who received the drug with food compared with 55% (11/20) of subjects who received the drug without food tested H. pylori-negative in a 13C-urea breath test (p = 0.031). Follow-up 13C-urea breath tests performed at least 3 months after therapy showed that H. pylori was eradicated in 14% (2/14) of subjects who received ranitidine bismuth citrate with food compared with 0% (0/18) of subjects who received ranitidine bismuth citrate without food (p = 0.183). The incidence of potentially drug-related adverse events was similar regardless of whether subjects received ranitidine bismuth citrate with or without food. Headache was the most common potentially drug-related adverse event.

CONCLUSIONS

These data demonstrate that administration of ranitidine bismuth citrate with food compared with without food significantly improves the suppression of H. pylori in infected volunteers.

Efficacy of oral ondansetron, a selective antagonist of 5-HT3 receptors, in the treatment of nausea and vomiting associated with cyclophosphamide-based chemotherapies. Ondansetron Study Group

We evaluated the efficacy and safety of oral ondansetron, a selective antagonist of 5-HT3 receptors, for the treatment of nausea and vomiting associated with cyclophosphamide-based chemotherapy (> 500 mg/m2). In this trial 324 chemotherapy-naive cancer patients, mostly females with breast cancer, were randomized to receive either placebo or ondansetron 1 mg, 4 mg, or 8 mg three times per day for 3 days. There were no differences in the doses of cyclophosphamide, doxorubicin, and methotrexate between the study groups. All ondansetron dose groups were superior to the placebo control group (p < .001) for all measured efficacy parameters (complete response, number of emetic episodes, therapeutic failures, need of rescue antiemetics). No emetic episodes were reported by 9 (12%), 29 (37%), 48 (64%), and 47 (66%) of the placebo patients and the 1-mg, 4-mg, and 8-mg dose of ondansetron patients, respectively. Nausea was reduced and food intake was improved for all the ondansetron groups. A more severe emetic response was observed in patients receiving cyclophosphamide and doxorubicin combination chemotherapy. In this subgroup of patients, 66%, 38%, 25%, and 16% of the placebo group and 1-mg, 4-mg, and 8-mg ondansetron patients, respectively, required rescue antiemetics. No significant toxic effects were observed in this study. A higher incidence of headaches and gastrointestinal complaints (constipation, abdominal pain) were observed in the three ondansetron groups. In conclusion, oral ondansetron is an effective and well-tolerated antiemetic treatment in the management of cancer patients receiving ambulatory cyclophosphamide-based chemotherapy. These results support the view that serotonin and 5-HT3 receptors play an important role in cyclophosphamide-induced nausea and vomiting.

Efficacy of oral ondansetron in the prevention of emesis in outpatients receiving cyclophosphamide-based chemotherapy. The Ondansetron Study Group

OBJECTIVE

To evaluate the efficacy and safety of oral ondansetron (Zofran) as an antiemetic in patients receiving cyclophosphamide-based chemotherapy.

DESIGN

A multicenter, randomized, double-blind, stratified, placebo-controlled trial conducted between March 1989 and January 1990.

SETTING

Twenty-seven oncology centers including university hospitals, community cancer centers, and private medical oncology practices.

PATIENTS

A total of 349 chemotherapy-naive patients having their first cycle of cyclophosphamide (> or = 450 mg/m2)-based chemotherapy. Patients also received methotrexate (> or = 30 mg/m2) or doxorubicin (> or = 35 mg/m2). All patients were evaluated for safety and 318 (91%) were evaluated for efficacy.

INTERVENTIONS

Patients were randomly assigned to one of four treatment groups: placebo, 1 mg, 4 mg, or 8 mg of ondansetron. Assigned study medication was taken three times per day for 3 consecutive days.

MEASUREMENTS

Time and number of emetic episodes as well as degree of nausea were recorded by patients for each of the 3 study days.

RESULTS

Compared with placebo, all three doses of ondansetron were superior (P < 0.001) in preventing vomiting and controlling nausea. A complete response (no emetic episodes) was observed in 19%, 57%, 65%, and 66% of patients in the placebo, 1-mg, 4-mg, and 8-mg ondansetron groups, respectively. For patients who received higher-dose cyclophosphamide and doxorubicin, a dose-related trend in antiemetic efficacy of ondansetron was observed. Mild headache and constipation were the most frequently reported adverse events. No extrapyramidal reactions were observed.

CONCLUSION

Oral ondansetron is a safe and effective antiemetic that is more efficacious than placebo for patients receiving cyclophosphamide-based chemotherapy.

Teratogenic and behavioral anomalies induced by acute exposure of mice to ethanol and their possible relation to fetal brain DNA synthesis

Physical and behavioral anomalies of fetal alcohol syndrome were studied after the i.p. administration of a single 3- or 6-g/kg dose of ethanol (25%, v/v) to gravid mice on either day 15 or day 18 of gestation. The physical effects of ethanol administered on either day 8, day 10, or day 12 of gestation (N = 6/group) were also examined and compared to the saline-administered controls. The identification of these anomalies and the effect of ethanol on the rate of fetal brain DNA synthesis were investigated. The physical anomalies were identified by standard procedures. Behavioral anomalies were measured as the inhibition of the development of various neonatal reflexes (N = 6-13/group) as compared to the saline-administered controls. The possible mechanism for these ethanol-induced abnormalities was identified by using [3H]thymidine to measure the rate of DNA synthesis (N = 6/group) in fetal mouse brains. Blood alcohol concentrations (N = 6/group) ranged from 410.2 mg/dl at 30 min to 25.8 mg/dl at 4.5 hr following the dosage of 3 g/kg of ethanol. Concentrations following the dosage of 6 g/kg of ethanol ranged from 753.7 mg/dl at 15 min to 127.1 mg/dl at 10.5 hr postinjection. Fetal and maternal weight gains were significantly inhibited compared to those of the controls. Various cranial facial, urogenital, skeletal, and cardiovascular anomalies were observed (P less than or equal to 0.05). Delays in the onset of the air and surface righting, visual placing, and negative geotaxis reflexes were observed for the ethanol-treated neonates, as compared to control values.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of the teratogenicity of morphine sulfate administered via a miniature implantable pump

A technique has been developed for the implantation of miniature infusion pumps in pregnant mice with minimal teratogenic and toxic side effects. In 7- to 10-day pregnant CF-1 mice receiving constant low doses of morphine sulfate via the infusion pump, the results, including fetal weight reduction and various skeletal and soft tissue abnormalities, were similar to those reported in previous investigations using single injections.