Effect of 7-day therapy with different doses of the proton pump inhibitor lansoprazole on the intragastric pH in healthy human subjects

Interchangeable Use of Proton Pump Inhibitors Based on Relative Potency

Although proton pump inhibitors (PPIs) are widely used, their relative potency and ideal dosing regimens remain unclear. We analyzed data from randomized clinical trials that performed pH testing in patients receiving solid-dose PPI formulations (omeprazole, esomeprazole, lansoprazole, pantoprazole, rabeprazole) for a minimum of 5 days. We used omeprazole equivalency and the surrogate biomarker, percentage time pH > 4 over a 24-hour period (pH4time), to compare PPI effectiveness for different PPIs given once, twice, or 3 times daily. We found that increasing strength of once-daily PPIs (9-64 mg omeprazole equivalents) increased pH4time linearly from approximately 10.0 to 15.6 hours; higher doses produced no further increase in pH4time. Increasing the frequency to twice-daily PPI increased pH4time linearly, from approximately 15.8 to 21.0 hours. Three-times daily PPIs performed similarly to twice-daily PPIs. The costs of PPIs varied greatly, but the cost variation was not directly related to potency. We conclude that PPIs can be used interchangeably based on potency. Using twice-daily PPIs is more effective in increasing efficacy increasing once-daily PPI dosage. Omeprazole and lansoprazole (30 mg) and 20 mg of esomeprazole rabeprazole are functionally equivalent.

Relative potency of proton-pump inhibitors-comparison of effects on intragastric pH

AIM

Comparative potency of proton-pump inhibitors (PPIs) is an important clinical issue. Most available trials have compared the different PPIs at one or a few selected specific dosages, making it difficult to derive quantitative equivalence dosages. Here we derived PPI dose equivalents based on a comprehensive assessment of dose-dependent effects on intragastric pH.

METHODS

All available clinical studies reporting the effects of PPIs on mean 24-h intragastric pH were sought from electronic databases including Medline. Studies included were restricted to those targeting the Caucasian population, and healthy volunteers or gastroesophageal reflux disease (GERD) patients. The dose-effect relationships for mean 24-h intragastric pH and for percentage of time with pH > 4 in 24 h were analyzed for each PPI using pharmacodynamic modeling with NONMEM and a model integrating all available data.

RESULTS

Fifty-seven studies fulfilled the inclusion criteria. Based on the mean 24-h gastric pH, the relative potencies of the five PPIs compared to omeprazole were 0.23, 0.90, 1.00, 1.60, and 1.82 for pantoprazole, lansoprazole, omeprazole, esomeprazole, and rabeprazole, respectively. Compared with healthy volunteers, patients with GERD needed a 1.9-fold higher dose and Helicobacter pylori-positive individuals needed only about 20% of the dose to achieve a given increase in mean 24-h intragastric pH.

CONCLUSION

The present meta-analysis provides quantitative estimates on clinical potency of individual PPIs that may be helpful when switching between PPIs and for assessing the cost-effectiveness of specific PPIs. However, our estimates must be viewed with caution because only a limited dose range has been tested and not exactly the same study conditions were applied for the different substances.

Absence of gastrointestinal infections in a cohort of patients with Zollinger-Ellison syndrome and other acid hypersecretors receiving long-term acid suppression with lansoprazole

BACKGROUND

The relationship between proton pump inhibitor therapy and other acid suppressing medications and the risk of gastrointestinal infections remains controversial.

METHODS

Patients enrolled in a long-term trial of lansoprazole for Zollinger-Ellison syndrome and other acid hypersecretory states had interval histories taken every six months regarding hospitalizations or other intercurrent medical conditions. All medications taken were also reviewed at each visit. In addition, available patients were specifically queried during the study period 2006-2007 regarding the development of any gastrointestinal infections, hospitalizations, and prescriptions for antibiotics.

RESULTS

Ninety patients were enrolled in our long-term study and 81 were available for review. The median basal gastric pH for the cohort after stabilization on therapy was 2.9 and ranged from 1.1 - 8.4 with a median pentagastrin stimulated gastric pH of 1.60 (range 1.0 - 8.2). No patient developed a clinically significant gastrointestinal infection during the study. The median patient years of follow-up were 6.25 years.

CONCLUSION

In a cohort of patients with gastric acid hypersecretion in whom acid secretion status was monitored on lansoprazole, all were free of significant gastrointestinal infections on long-term follow-up.

TRIAL REGISTRATION

NCT00204373.

Acid control with esomeprazole and lansoprazole: a comparative dose-response study

OBJECTIVE

To determine the level of acid control and the dose-response relationships achieved with esomeprazole and lansoprazole. These data are relevant in helping clinicians to decide on whether to increase a proton-pump inhibitor dose, or whether to switch to an alterative drug for increased acid control.

MATERIAL AND METHODS

In an open-label, single-centre, randomized, six-way crossover study, 40 healthy subjects received esomeprazole 20, 40 and 80 mg, and lansoprazole 15, 30 and 60 mg once daily for 5 days. The mean time with intragastric pH >4 and mean 24-h median intragastric pH on day 5 were analyzed using a mixed-model ANOVA. Post-hoc analyses were completed for 0-12-h (daytime) and 12-24-h (night-time) post-dose intervals.

RESULTS

Increasing the dose of esomeprazole from 20 mg to 40 mg resulted in significantly improved acid control over 0-12, 12-24 and 0-24 h post-dose (p<0.001), but no significant improvement in acid control for either period was seen when further increasing the dose to 80 mg. Increasing the dose of lansoprazole from 15 mg to 30 mg or from 30 mg to 60 mg significantly improved acid control over 0-12 and 0-24 h (p<0.01) but not over 12-24 h. With the exception of the esomeprazole 20 mg versus lansoprazole 30 mg comparisons, and the esomeprazole 20 mg versus lansoprazole 15 mg during 12-24 h post-dose comparison, esomeprazole provided significantly greater acid control than lansoprazole at each dose level over 0-12, 12-24 and 0-24 h (p<0.05). Mean 24-h median intragastric pH was higher following esomeprazole dosing compared with lansoprazole at each dose level.

CONCLUSIONS

For low-, standard- and double-dose comparisons, esomeprazole achieved greater elevation of gastric pH and better acid control in more subjects than lansoprazole. Use of esomeprazole may therefore reduce the need for dose adaptations or drug switching.

Rabeprazole 10 mg twice daily is superior to 20 mg once daily for night-time gastric acid suppression

BACKGROUND

Insufficient acid suppression is one of the main causes of proton pump inhibitor-refractory gastro-oesophageal reflux disease.

AIM

To achieve more potent and long-lasting acid suppression, different dosage regimens of rabeprazole were compared in relation to the CYP2C19 genotype status.

METHODS

In a cross-over study, 18 healthy Helicobacter pylori-negative males (six homozygous extensive metabolizers, six heterozygous extensive metabolizers and six poor metabolizers) were given rabeprazole 10 mg once daily, 20 mg once daily or 10 mg twice daily, or water only (baseline data), for 7 days each. On day 7 of each regimen, 24-h intragastric pH-metry was performed.

RESULTS

No significant differences were observed in median pH values and pH>4 holding time ratios between rabeprazole 10 mg once daily and 20 mg once daily. However, with rabeprazole 10 mg twice daily, these parameters were significantly higher than those with 20 mg once daily. The potency of acid suppression by rabeprazole was influenced by the CYP2C19 genotype status. The differences were somewhat significant but not large. The incidence of nocturnal acid breakthrough was lowest with rabeprazole 10 mg twice daily.

CONCLUSIONS

Rabeprazole 10 mg twice daily, not 20 mg once daily, should be administered to achieve more potent and long-lasting acid suppression.

Daily low-dose versus alternate day full-dose lansoprazole in the maintenance treatment of reflux esophagitis

OBJECTIVE

For the long term maintenance treatment of reflux esophagitis several strategies have been proposed with the aim of reducing the daily dosage or the frequency of drug administration. However, the available clinical studies are scarce and are often not controlled or conducted on a reduced number of cases. We aimed to compare the efficacy of two doses of lansoprazole (15 mg once daily and 30 mg on alternate days) in maintaining endoscopic healing and symptom relief over a 6-month period.

METHODS

One hundred thirty-seven patients with Savary-Miller grades I-III reflux esophagitis healed after an 8-wk treatment with lansoprazole (30 mg daily) were divided into two main groups for a 6-month maintenance therapy period: lansoprazole, 15 mg once daily (group 15qd) and lansoprazole, 30 mg on alternate days (group 30qod). These two main groups were further subdivided according to the time of drug administration; morning (15qdm and 30qodm) and evening (15qde and 30qode). Each patient underwent esophagogastroduodenoscopy before entry into the study, after 8 wk of acute therapy, and after 6 months of maintenance therapy; 24-h esophageal-gastric pH monitoring was performed at baseline and during the last week of maintenance therapy.

RESULTS

At the end of the maintenance period the recurrence of esophagitis was observed in 12.1% of group 15qd patients and in 19.0% of group 30qod patients, without significant differences between the two groups. The frequency of patients without reflux symptoms after the 6-month period was the same for both groups; however, a significant increase of heartburn was observed in group 30qod patients (from 12.1% to 28.6%, p = 0.007). The time of drug administration (morning and evening) had no influence on the outcome of treatment. Both regimens significantly reduced esophageal acid exposure time and increased the median 24-h gastric pH.

CONCLUSIONS

Both long term lansoprazole regimens are equally effective in preventing the recurrence of esophagitis, independent of the modality of drug administration. The daily administration seems to have a better effect on the prevention of symptom recurrence.

Lansoprazole: an update of its place in the management of acid-related disorders

Lansoprazole is an inhibitor of gastric acid secretion and also exhibits antibacterial activity against Helicobacter pylori in vitro. Current therapy for peptic ulcer disease focuses on the eradication of H. pylori infection with maintenance therapy indicated in those patients who are not cured of H. pylori and those with ulcers resistant to healing. Lansoprazole 30 mg combined with amoxicillin 1g, clarithromycin 250 or 500mg, or metronidazole 400 mg twice daily was associated with eradication rates ranging from 71 to 94%, and ulcer healing rates were generally >80% in well designed studies. In addition, it was as effective as omeprazole- or rabeprazole-based regimens which included these antimicrobial agents. Maintenance therapy with lansoprazole 30 mg/day was significantly more effective than either placebo or ranitidine in preventing ulcer relapse. Importantly, preliminary data suggest that lansoprazole-based eradication therapy is effective in children and the elderly. In the short-term treatment of patients with gastro-oesophageal reflux disease (GORD), lansoprazole 15, 30 or 60 mg/day was significantly more effective than placebo, ranitidine 300 mg/day or cisapride 40 mg/day and similar in efficacy to pantoprazole 40 mg/day in terms of healing of oesophagitis. Lansoprazole 30 mg/day, omeprazole 20 mg/day and pantoprazole 40 mg/day all provided similar symptom relief in these patients. In patients with healed oesophagitis. 12-month maintenance therapy with lansoprazole 15 or 30 mg/day prevented recurrence and was similar to or more effective than omeprazole 10 or 20 mg/day. Available data in patients with NSAID-related disorders or acid-related dyspepsia suggest that lansoprazole is effective in these patients in terms of the prevention of NSAID-related gastrointestinal complications, ulcer healing and symptom relief. Meta-analytic data and postmarketing surveillance in >30,000 patients indicate that lansoprazole is well tolerated both as monotherapy and in combination with antimicrobial agents. After lansoprazole monotherapy commonly reported adverse events included dose-dependent diarrhoea, nausea/vomiting, headache and abdominal pain. After short-term treatment in patients with peptic ulcer, GORD, dyspepsia and gastritis the incidence of adverse events associated with lansoprazole was generally < or = 5%. Similar adverse events were seen in long-term trials, although the incidence was generally higher (< or = 10%). When lansoprazole was administered in combination with amoxicillin, clarithromycin or metronidazole adverse events included diarrhoea, headache and taste disturbance. In conclusion, lansoprazole-based triple therapy is an effective treatment option for the eradication of H. pylori infection in patients with peptic ulcer disease. Preliminary data suggest it may have an important role in the management of this infection in children and the elderly. In the short-term management of GORD, lansoprazole monotherapy offers a more effective alternative to histamine H2-receptor antagonists and initial data indicate that it is an effective short-term treatment option in children and adolescents. In adults lansoprazole maintenance therapy is also an established treatment option for the long-term management of this chronic disease. Lansoprazole has a role in the treatment and prevention of NSAID-related ulcers and the treatment of acid-related dyspepsia; however, further studies are needed to confirm its place in these indications. Lansoprazole has emerged as a useful and well tolerated treatment option in the management of acid-related disorders.

Proton pump inhibitor resistance in the treatment of laryngopharyngeal reflux

OBJECTIVE

To describe the occurrence of relative proton pump inhibitor (PPI) drug resistance in the treatment of laryngopharyngeal reflux (LPR).

STUDY DESIGN AND SETTING

A retrospective review was performed for 1053 consecutive adults undergoing double-probe (simultaneous esophageal and pharyngeal) pH testing in our laboratory. Two hundred five patients who had pH studies performed while taking at least a daily dose of PPI therapy were identified; 167 qualified for further analysis. The pH data was reviewed for the presence of abnormalities in either esophageal or pharyngeal acid exposure to evaluate drug efficacy.

RESULTS

Forty-four percent (74/167) of the study patients demonstrated abnormal levels of acid exposure. Results were further analyzed to compare failure rates based on different dosage regimens. Patients on once daily doses of PPI failed at a rate of 56%, with lower failure rates for higher-dose regimens.

CONCLUSIONS

A significant number of LPR patients on PPI therapy demonstrate relative drug resistance.

Helicobacter pylori eradication and standardized 3-month omeprazole therapy in functional dyspepsia

OBJECTIVES

The role of Helicobacter pylori in functional dyspepsia remains unclear. This study evaluated the long term consequences for symptoms and quality of life in patients with H. pylori-positive functional dyspepsia after H. pylori eradication therapy with a standardized 3-month omeprazole treatment.

METHODS

A total of 151 H. pylori-positive patients with functional dyspepsia were randomized to receive either eradication therapy or placebo-antibiotics. The initial medication was administered in a double-blinded fashion. In addition, to standardize acid suppression, every patient received omeprazole therapy for the first 3-month period. Dyspeptic symptoms were evaluated by a questionnaire every 3 months, and quality of life was measured by a validated RAND 36-item health survey 1.0 questionnaire at the beginning of the study and after 12 months of follow-up. As the main outcome measure, the scores of patients who had received H. pylori eradication therapy and omeprazole were compared with those who received placebo and omeprazole during the 12 months of follow-up.

RESULTS

A total of 136 patients completed the 1-yr follow-up. In all, 77 patients received eradication therapy and 74 patients remained as controls. After 12 months, the mean reduction in the dyspepsia score was 28.8% in patients with H. pylori eradication therapy and 21.7% in the control group. The reduction of dyspepsia was significant (p < 0.0001) in both groups compared to baseline value, but no statistically significant differences in changes of dyspeptic symptoms or in quality of life were demonstrated between the H. pylori eradication therapy group and controls after 1 yr. In both patient groups, regurgitation (p < 0.001) and heartburn (p < 0.01) revealed relapse after cessation of 3-month omeprazole treatment.

CONCLUSIONS

No clear differences in symptoms or in quality of life were found between patients treated with H. pylori eradication therapy and omeprazole compared with patients receiving placebo and omeprazole after 1 yr. Regardless of H. pylori status, omeprazole treatment reduced heartburn and regurgitation. The placebo effect on the symptoms of functional dyspepsia and on quality of life was marked.

Does short-term treatment with proton pump inhibitors cause rebound aggravation of symptoms?

BACKGROUND

Rebound acid hypersecretion might occur after treatment with proton pump inhibitors. This study looks for a rebound aggravation of symptoms after short-term treatment with lansoprazole.

STUDY

Sixty-two patients (19 men and 43 women; mean age, 54 years; range, 32-77 years) with heartburn and regurgitation and normal upper endoscopy findings were studied in a randomized, double-blind, placebo-controlled trial with a crossover design. There were two 5-day treatment periods with lansoprazole 60 mg once daily or placebo in random order, separated by a 9-day washout period. Reflux, total, and antacid scores were calculated for each of the treatment periods. Higher scores during the placebo period in the group given lansoprazole first than in the group given placebo first indicated a rebound aggravation of symptoms.

RESULTS

The mean symptom scores during the placebo period in the groups given lansoprazole first and placebo first were as follows: reflux score, 21.5 and 17.6, respectively (not significant); total score, 11.2 and 10.3, respectively (not significant); and antacid score, 8.2 and 7.2, respectively (not significant).

CONCLUSIONS

There is no indication of a rebound aggravation of symptoms 12 to 14 days after a 5-day treatment with lansoprazole 60 mg once daily in patients with reflux symptoms.

Proton pump inhibitors in the treatment of gastro-oesophageal reflux disease

Gastro-oesophageal reflux disease (GERD) is the most common peptic acid disease in the western world and is the commonest indication for acid suppression therapy. Major advances have been made over the past 30 years in the understanding of lower oesophageal sphincter function and the mechanism of acid secretion. Developments in surgical and pharmacological therapy have paralleled these advances. Pharmacotherapy for GERD has evolved from antacids to H2-receptor antagonists (H2RAs) to prokinetics to proton pump inhibitors (PPIs). The H2RAs, while modestly effective in symptom relief and healing of GERD, are limited by pharmacological tolerance. The prokinetics (metoclopramide and cisapride) are limited by low efficacy, pharmacological tolerance and toxicity. The PPIs have emerged as the most effective therapy for symptom relief, healing and long-term maintenance. They have also proved to be remarkably safe and cost-effective in long-term therapy. This review evaluates the pharmacology, efficacy, tolerability, safety and cost-effectiveness of the four currently available PPIs, lansoprazole, omeprazole, pantoprazole and rabeprazole, in the treatment of GERD.