Comparison of lansoprazole with omeprazole on 24-hour intragastric pH, acid secretion and serum gastrin in healthy volunteers

Effects of H2-Receptor Antagonists on the Exposure of Dacomitinib

Dacomitinib is an irreversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor indicated for the treatment of patients with advanced non-small-cell lung cancer (NSCLC) and EGFR-activating mutations. Proton-pump inhibitors decreased dacomitinib exposure. This analysis summarizes the effect of Histamine-2 receptor antagonists (H2RAs) on dacomitinib exposure. A within-patient comparison of the steady-state trough concentrations (Ctrough,ss) of dacomitinib and its active metabolite and active moiety with and without concomitant use of H2RAs was conducted using a linear mixed effects model with pooled data from 11 clinical studies in patients with NSCLC. An oral absorption physiologically based pharmacokinetic (PBPK) model was constructed and verified using clinical pharmacokinetic (PK) data after a single dose of dacomitinib in healthy volunteers to estimate the effect of gastric pH altered by an H2RA on dacomitinib's PKs. The adjusted geometric mean of the dacomitinib Ctrough,ss of the dacomitinib parent, metabolite and active moiety following co-administration with an H2RA was approximately 86%, 104% and 100% relative to that following dacomitinib 45 mg administration without an H2RA (p > 0.05). The PBPK modeling showed negligible change in dacomitinib maximum concentration (Cmax) and area under the drug concentration-time curve (AUC) over 0-24 h after H2RA administration when compared with those administered dacomitinib alone. Co-administration of an H2RA with dacomitinib is not expected to have any clinically relevant effect on dacomitinib exposure.

Chemotherapy-induced gastrointestinal toxicity: Pathogenesis and current management

Chemotherapy is the most common treatment for malignant tumors. However, chemotherapy-induced gastrointestinal toxicity (CIGT) has been a major concern for cancer patients, which reduces their quality of life and leads to treatment intolerance and even cessation. Nevertheless, prevention and treatment for CIGT are challenging, due to the prevalence and complexity of the condition. Chemotherapeutic drugs directly damage gastrointestinal mucosa to induce CIGT, including nausea, vomiting, anorexia, gastrointestinal mucositis, and diarrhea, etc. The pathogenesis of CIGT involves multiple factors, such as gut microbiota disorders, inflammatory responses and abnormal neurotransmitter levels, that synergistically contribute to its occurrence and development. In particular, the dysbiosis of gut microbiota is usually linked to abnormal immune responses that increases inflammatory cytokines' expression, which is a common characteristic of many types of CIGT. Chemotherapy-induced intestinal neurotoxicity is also a vital concern in CIGT. Currently, modern medicine is the dominant treatment of CIGT, however, traditional Chinese medicine (TCM) has attracted interest as a complementary and alternative therapy that can greatly alleviate CIGT. Accordingly, this review aimed to comprehensively summarize the pathogenesis and current management of CIGT using PubMed and Google Scholar databases, and proposed that future research for CIGT should focus on the gut microbiota, intestinal neurotoxicity, and promising TCM therapies, which may help to develop more effective interventions and optimize managements of CIGT.

Treatment outcomes in patients with globus: A randomized control trial of psychoeducation, neuromodulators, and proton pump inhibitors

BACKGROUND

Globus is a persistent or intermittent nonpainful sensation of a lump or foreign body, which markedly affect patient's quality of life. Treatment options for globus are limited and unsatisfying. This study aims to compare the effects of cognitive-behavioral-theory-based psychoeducation (CBT), neuromodulators (NMD), and proton pump inhibitor (PPI) on treatment outcomes in patients with globus.

METHODS

Eligible patients were randomly received CBT, 0.5 mg flupenthixol and 10 mg melitracen; NMD, or omeprazole 20 mg; PPI, for 4 weeks. The primary endpoint was the reduction in symptom scores; Glasgow Edinburgh Throat Scale (GETS). The secondary endpoints included treatment efficacy on Reflux Symptom Index (RSI), Hospital Anxiety Depression Scale (HADS), and quality of life (QoL) based on a 36-item short-form health survey (SF-36). Treatment compliance and adverse effects were recorded.

KEY RESULTS

Forty patients were completed study. Baseline characteristics between the groups were comparable. By the end of treatment, both CBT and NMD provided greater reduction in GETS than PPI (CBT vs PPI; 6.46 ± 8.56 vs 0.21 ± 5.42; p = 0.031, NMD vs PPI; 6.92 ± 9.85 vs 0.21 ± 5.42; p = 0.036). The improvement of RSI, HADS, and SF-36 among the groups was similar. Neuromodulators caused more adverse events.

CONCLUSIONS & INFERENCES

Both CBT and NMD provided equally effective treatment and better than PPI in patients with globus determined by the reduction in GETS. The improvement in RSI, HADS, and QoL of the three groups was not different. Given less of adverse effect than NMD, CBT should be considered as a substantial treatment.

Application of Physiologically-Based Pharmacokinetic Modeling to Predict Gastric pH-Dependent Drug-Drug Interactions for Weak Base Drugs

Weak‐base drugs are susceptible to drug–drug interactions (DDIs) when coadministered with gastric acid–reducing agents (ARAs). We developed PBPK models to evaluate the potential of such pH‐dependent DDIs for four weak‐base drugs, i.e., tapentadol, darunavir, erlotinib, and saxagliptin. The physiologically‐based pharmacokinetic (PBPK) models of these drugs were first optimized using pharmacokinetic (PK) data following oral administration without ARAs, which were then verified with data from additional PK studies in the presence and absence of food. The models were subsequently used to predict the extent of DDIs with ARA coadministration. Sensitivity analysis was conducted to explore the impact of gastric pH on quantitative prediction of drug exposure in the presence of ARA. The results suggested that the PBPK models developed could adequately describe the lack of the effect of ARA on the PK of tapentadol, darunavir, and saxagliptin and could qualitatively predict the effect of ARA in reducing the absorption of erlotinib. Further studies involving more drugs with positive pH‐dependent DDIs are needed to confirm the findings and broaden our knowledge base to further improve the utilization of PBPK modeling to evaluate pH‐dependent DDI potential.

Rabeprazole and Psychiatric Symptoms

Objective:

To report the case of a patient who developed marked anxiety associated with episodes of panic attacks after starting rabeprazole therapy.

Case Summary:

An otherwise healthy 55-year-old woman was prescribed rabeprazole 20 mg/day administered in the morning tor persistent symptoms of dyspepsia. Ten days later, she presented with a 7 day history of marked anxiety associated with panic attacks, night terror (pavor nocturnus), episodic mental confusion, and attention deficit. Within 2 days of discontinuing rabeprazole, the patient recovered completely from the neuropsychiatric manifestations. Subsequent esomeprazole therapy did not cause psychiatric symptoms.

Discussion:

Rabeprazole-induced hypergastrinemia may have played a role in this neuropsychiatric adverse reaction. Several lines of evidence have indicated that gastrin-releasing peptide, whose release is mediated by proton pump inhibitor (PPI)–induced secretion of gastrin, is involved in regulating aspects of behavior that might be altered in disorders such as anxiety, depression, and dementia. The fact that rabeprazole has the highest capacity of inducing gastrin increase compared with other PPIs might explain why our patient's panic symptoms disappeared after switching to esomeprazole. Based on the Naranjo probability scale, rabeprazole was the probable cause of the adverse reaction.

Conclusions:

Specific studies are needed to investigate the potential role of PPI-induced hypergastrinemia in neuropsychiatrie adverse reactions.

Comparison of paroxetine and amitriptyline in the treatment of refractory globus pharyngeus

BACKGROUND

Clinical trials of antidepressants for treatment of globus are generally rare, let alone for refractory globus pharyngeus.

AIMS

To illustrate the efficacy and side-effects of antidepressants between paroxetine and amitriptyline for refractory globus patients.

METHODS

Refractory globus patients were randomized into paroxetine group; amitriptyline group and lansoprazole group for 6-week treatment. All the subjects were asked to complete the following questionnaires pre- and post-therapy: Glasgow Edinburgh Throat Scale (GETS), Pittsburgh Sleep Quality Index, Hamilton Rating Scale Anxiety/Depression and Medical outcome short-form 36. Treatment response was defined as a >50% reduction in the GETS score.

RESULTS

One hundred and forty-eight patients completed the study. After 6 week treatment, 71.7% of paroxetine group (33/46) were calculated as treatment response, significantly higher than that in amitriptyline group (46.2%, 24/52) and lansoprazole group (14.0%, 7/50). Compared with lansoprazole group or amitriptyline group, a more distinct improvement of emotional well-being, quality of life and quality of sleep were observed in paroxetine group after 6-week treatment.

CONCLUSION

Paroxetine therapy is more efficacious than empirical high-dose antisecretory treatment, or even the low-dose amitriptyline therapy in alleviating globus symptoms, and producing global improvements for refractory globus patients.

Therapeutic substitution post-patent expiry: the cases of ACE inhibitors and proton pump inhibitors

This paper examines whether there is a switch in total (originator and generic) consumption after generic entry from molecules that face generic competition towards other molecules of the same class, which are still in-patent. Data from six European countries for the time period 1991 to 2006 are used to study the cases of angiotensin-converting enzyme inhibitors and proton pump inhibitors. Empirical evidence shows that patent expiry of captopril and enalapril led to a switch in total (off-patent originator and generic) consumption towards other in-patent angiotensin-converting enzyme inhibitors, whereas patent expiry of omeprazole led to a switch in consumption towards other proton pump inhibitors. This phenomenon makes generic policies ineffective and results in an increase in pharmaceutical expenditure due to the absence of generic alternatives in the market of in-patent molecules.

Gastric acid, calcium absorption, and their impact on bone health

Calcium balance is essential for a multitude of physiological processes, ranging from cell signaling to maintenance of bone health. Adequate intestinal absorption of calcium is a major factor for maintaining systemic calcium homeostasis. Recent observations indicate that a reduction of gastric acidity may impair effective calcium uptake through the intestine. This article reviews the physiology of gastric acid secretion, intestinal calcium absorption, and their respective neuroendocrine regulation and explores the physiological basis of a potential link between these individual systems.

Clinical predictors for response to proton pump inhibitor treatment in patients with globus

Background/Aims

Globus is a persistent or intermittent non-painful sensation of a lump or foreign body in the throat. Given the benign nature of the condition and the association of gastroesophageal reflux disease, empirical therapy with proton pump inhibitor seems reasonable for patients with typical globus. The aim of this study was to investigate the clinical predictors for symptom response to short-term proton pump inhibitor treatment in patients with globus symptom.

Methods

Fifty-four patients with globus symptom were enrolled prospectively. All patients were treated with pantoprazole 40 mg daily for 4 weeks. Treatment response was defined as a > 50% reduction in symptom scores between symptom assessments. Univariate and multivariate logistic regression analysis between responders and non-responders was performed to identify variables predicting response to pantoprazole treatment.

Results

Of the 54 consecutive patients considered, 13 were excluded on the basis of exclusion criteria and/or refusal to participate in the study. Finally, 41 patients were included in this study. After 4-week pantoprazole treatment, 22 patients (53.7%) were classified as responders. On multivariate analysis, the presence of reflux symptom was associated with a higher response rate to 4-week pantoprazole treatment (OR, 68.56; P = 0.043), and long symptom duration (≥ 3 months) were associated with a lower response rate to pantoprazole treatment (OR, 0.03; P = 0.034).

Conclusions

Presence of reflux symptom and short symptom duration were independent predictors of responsiveness to 4-week pantoprazole treatment in patients with globus.

Pharmacokinetics and pharmacodynamics of the proton pump inhibitors

Proton pump inhibitor (PPI) is a prodrug which is activated by acid. Activated PPI binds covalently to the gastric H⁺, K⁺-ATPase via disulfide bond. Cys813 is the primary site responsible for the inhibition of acid pump enzyme, where PPIs bind. Omeprazole was the first PPI introduced in market, followed by pantoprazole, lansoprazole and rabeprazole. Though these PPIs share the core structures benzimidazole and pyridine, their pharmacokinetics and pharmacodynamics are a little different. Several factors must be considered in understanding the pharmacodynamics of PPIs, including: accumulation of PPI in the parietal cell, the proportion of the pump enzyme located at the canaliculus, de novo synthesis of new pump enzyme, metabolism of PPI, amounts of covalent binding of PPI in the parietal cell, and the stability of PPI binding. PPIs have about 1hour of elimination half-life. Area under the plasmic concentration curve and the intragastric pH profile are very good indicators for evaluating PPI efficacy. Though CYP2C19 and CYP3A4 polymorphism are major components of PPI metabolism, the pharmacokinetics and pharmacodynamics of racemic mixture of PPIs depend on the CYP2C19 genotype status. S-omeprazole is relatively insensitive to CYP2C19, so better control of the intragastric pH is achieved. Similarly, R-lansoprazole was developed in order to increase the drug activity. Delayed-release formulation resulted in a longer duration of effective concentration of R-lansoprazole in blood, in addition to metabolic advantage. Thus, dexlansoprazole showed best control of the intragastric pH among the present PPIs. Overall, PPIs made significant progress in the management of acid-related diseases and improved health-related quality of life.

Recent advances in noncardiac chest pain in Korea

Gastroesophageal reflux disease (GERD) is the most common cause of noncardiac chest pain (NCCP) and is present in up to 60% of patients with NCCP in Western countries. In Korea, after a reasonable cardiac evaluation, GERD is reported to underlie 41% of NCCP cases. Typical reflux symptoms are frequent in Korean patients suffering from NCCP. Therefore, a careful history of the predominant symptoms, including heartburn and acid regurgitation, is relatively indicative of the GERD diagnosis in Korea. In Korea, in contrast to Western countries, patients aged 40 years and over who have been diagnosed with NCCP but who are without alarming features should undergo endoscopy to exclude gastric cancer or peptic ulcers because of the higher prevalence of peptic ulcer disease and gastric cancers in the region. In a primary care setting, in the absence of any alarming symptoms, a symptomatic response to a trial of a proton pump inhibitor (PPI) is sufficient for the presumptive diagnosis of GERD. In addition, the optimal duration of a PPI test may be at least 2 weeks, as GERD symptoms tend to be less frequent or atypical in Korean patients than in patients from Western countries. In patients diagnosed with GERD-related NCCP, long-term therapy (more than 2 months) with double the standard dose of a PPI is required to alleviate symptoms. Esophageal dysmotility is relatively uncommon, and pain modulators seem to offer significant improvement of chest pain control in non-GERD-related NCCP. Most traditionally available tricyclics or heterocyclics have many undesirable effects. Therefore, newer drugs with fewer side effects (for example, the serotonin - norepinephrine reuptake inhibitors) may be needed.

A multicenter, randomized, comparative study to determine the appropriate dose of lansoprazole for use in the diagnostic test for gastroesophageal reflux disease

Background/Aims

The diagnostic proton pump inhibitor test (PPI test) is a method used in diagnosing gastroesophageal reflux disease (GERD). This study aimed to determine the appropriate dose of lansoprazole for use in the diagnostic test for GERD.

Methods

This study was a randomized, controlled, multicenter trial in the Daegu-Gyeongbuk area. Patients with typical reflux symptoms such as regurgitation and heartburn for at least three months were enrolled in this study. Patients were divided into two groups, the erosive reflux disease (ERD) group and the non-erosive reflux disease (NERD) group, and randomized to 14 days of treatment with lansoprazole at a dose of 15 mg, 30 mg or 60 mg once daily. The PPI test was considered positive if the patient's symptoms improved by more than 50%.

Results

A total of 218 patients were enrolled, and analysis was performed on the 188 patients who completed the study. The PPI test was positive in 93.2% of the ERD group and 87.2% of the NERD group. A positive PPI test was observed in 91.7%, 89.4%, and 87.2% of the 15 mg, 30 mg, and 60 mg groups, respectively. Significant symptom score changes were observed starting on day 8 for the 15 mg, 30 mg, and 60 mg groups.

Conclusions

In this multicenter, randomized study of Korean patients, the standard dose of lansoprazole was as effective as a high dose of lansoprazole in relieving the symptoms of GERD, regardless of the presence of ERD, by day 14 of treatment.

The proton pump inhibitor test for gastroesophageal reflux disease: optimal cut-off value and duration

BACKGROUND

There is no accepted gold standard for the diagnosis of gastroesophageal reflux disease (GERD).

AIM

To assess the optimal cut-off value and duration of the proton pump inhibitor (PPI) test in GERD patients with and without oesophagitis.

METHODS

Prospective study of 544 patients undergoing upper GI endoscopy and treated for 2 weeks with PPIs at double dose, and for 3 additional months at standard dose. The status of the patient at end of treatment was used as an independent diagnostic standard, i.e. patients completely asymptomatic were considered as "true" GERD patients.

RESULTS

PPI test was positive in 89.7-97.8% of the patients according to the cut-off or duration of test used. Test sensitivity ranged from 95.5% to 98.8%, whereas specificity did not exceed 36.3%. Positive predictive values ranged from 87% to 80%, negative predictive values ranged from 58% to 70%, respectively.

CONCLUSIONS

The PPI test is a sensitive but poorly specific test in GERD patients. Its optimal duration is 1 week, and the optimal cut-off value is a decrease of heartburn score ≥75%. The diagnostic yield is higher in erosive oesophagitis compared with non-erosive reflux disease patients, similarly to the symptomatic response to 3-month PPI therapy.

The proton pump inhibitor test and the diagnosis of gastroesophageal reflux disease

There continues to be significant controversy related to diagnostic testing for gastroesophageal reflux disease (GERD). Symptoms of GERD may be associated with physiologic esophageal acid exposure measured by intraesophageal pH monitoring or pH-impedance monitoring, and a significant percentage of patients with abnormal esophageal acid (or weak acid) exposure have no or minimal clinical symptoms of reflux. On the other hand, endoscopic lesions are only present in a minority of GERD patients. In clinical practice, presumptive diagnosis of GERD is reasonably assumed by the substantial reduction or elimination of suspected reflux symptoms during the therapeutic trial of acid reduction therapy, the so-called proton pump inhibitor (PPI) test. We aimed to assess the optimal cutoff value and duration of this test in GERD patients with and without esophagitis. We conducted a prospective study of 544 patients, endoscopically investigated and treated for 2 weeks with PPIs at double dose, and for an additional 3 months at standard dose. The status of the patient at the end of the study was used as an independent diagnostic standard. We found esophagitis present in 55.8% and absent in 44.2% of patients (corresponding to a diagnosis of nonerosive reflux disease [NERD]). The test was positive in 89.7-97.8% of the patients according to the cutoff or duration of the test used. The sensitivity of the PPI test was excellent, ranging from 95.5 to 98.8%, whereas the specificity was poor, not exceeding 36.3%. Erosive esophagitis patients responded more favorably to the PPI test and subsequent PPI therapy compared with NERD patients. In conclusion, the PPI test is a sensitive but less specific test. Its optimal duration is 1 week, and the optimal cutoff value is a decrease of heartburn score of more than 75%. NERD patients respond less satisfactorily to PPIs, even when functional heartburn patients are excluded and only 'true' NERD patients are considered.

High-output fistula

Despite improvements in healthcare delivery, mortality rates for high-output fistulae remain unchanged. The pathophysiology and causes of fistulae are reviewed in this article. An overview of the diagnostic procedures to delineate fistulae and underlying bowel disease together with their complications is included. Management of high-output fistulae consists of assessment and stabilization of patients, followed by conservative management by a multidisciplinary team until spontaneous or surgical closure of fistulae.

Safety of the long-term use of proton pump inhibitors

The proton pump inhibitors (PPIs) as a class are remarkably safe and effective for persons with peptic ulcer disorders. Serious adverse events are extremely rare for PPIs, with case reports of interstitial nephritis with omeprazole, hepatitis with omeprazole and lansoprazole, and disputed visual disturbances with pantoprazole and omeprazole. PPI use is associated with the development of fundic gland polyps (FGP); stopping PPIs is associated with regression of FGP. In the absence of Helicobacter pylori infection, the long-term use of PPIs has not been convincingly proven to cause or be associated with the progression of pre-existing chronic gastritis or gastric atrophy or intestinal metaplasia. Mild/modest hypergastrinemia is a physiological response to the reduction in gastric acid secretion due to any cause. The long-term use of PPIs has not been convincingly proven to cause enterochromaffin-like cell hyperplasia or carcinoid tumors. PPIs increase the risk of community acquired pneumonia, but not of hospital acquired (nosocomial) pneumonia. There is no data to support particular care in prescribing PPI therapy due to concerns about risk of hip fracture with the long-term use of PPIs. Long-term use of PPIs does not lead to vitamin B12 deficiencies, except possibly in the elderly, or in persons with Zollinger-Ellison Syndrome who are on high doses of PPI for prolonged periods of time. There is no convincingly proven data that PPIs increase the risk of Clostridium difficile-associated diarrhea in persons in the community. The discontinuation of PPIs may result in rebound symptoms requiring further and even continuous PPI use for suppression of symptoms. As with all medications, the key is to use PPIs only when clearly indicated, and to reassess continued use so that long-term therapy is used judiciously. Thus, in summary, the PPIs are a safe class of medications to use long-term in persons in whom there is a clear need for the maintenance of extensive acid inhibition.

Comparison of one-week and two-week empirical trial with a high-dose rabeprazole in non-cardiac chest pain patients

BACKGROUND

In patients with non-cardiac chest pain (NCCP), the optimal duration of an empirical trial with a high-dose proton pump inhibitor (PPI) is unclear. We aimed to compare the efficacy of one-week and two-week PPI trial in patients with weekly or more than weekly NCCP and to determine its optimal duration for diagnosing gastroesophageal reflux disease (GERD)-related NCCP.

METHODS

Forty-two patients with at least weekly NCCP were enrolled. The baseline symptoms were assessed using a daily symptom diary for seven days. Also, esophago-gastro-duodenoscopy and 24 h esophageal pH monitoring were performed for the diagnosis of GERD. Then, patients were treated with rabeprazole 20 mg twice daily for 14 days. To assess NCCP improvement during the PPI trial, the first week and the second week symptom diary were kept for 1-7 and 8-14 days. The PPI test was considered positive if a symptom score improved (50% compared to the baseline.

RESULTS

There was no significant difference for a positive PPI test between GERD-related NCCP group (n = 8, 50%) and non GERD-related NCCP group (n = 6, 23%) during the first week of the PPI test. However, during the second week, GERD-related NCCP had a higher positive PPI test (n = 13, 81%) than non GERD-related NCCP (n = 7, 27%) (P = 0.001) with a sensitivity and specificity of 81% and 62%, respectively.

CONCLUSIONS

The rabeprazole empirical trial was diagnostic for patients with GERD-related NCCP, and its optimal duration was determined to be at least two weeks.

Continuous distal oesophageal acidification decreases postprandial gastric acidity in healthy human subjects

BACKGROUND

Previously, we hypothesized that exposing the distal oesophagus to acid signals the stomach to decrease gastric acidity.

AIM

To test the hypothesis that exposing the distal oesophagus to acid signals the stomach to decrease gastric acidity.

METHODS

Twenty-two healthy humans ingested a standard meal containing [(14)C]octanoic acid and [(13)C]glycine over 30 min on 2 separate occasions. Gastric pH was measured for 90 min before and 240 min after the meal. 10 mm HCl was infused continuously at 1 mL/min into either the distal oesophagus or stomach in a 2-way crossover fashion for 60 min before and 240 min after the meal. Gastric emptying of solid and liquid were determined with breath tests.

RESULTS

Compared to gastric infusion, oesophageal infusion significantly decreased gastric acidity after the meal, but not before the meal and the magnitude of the decrease varied directly with gastric acidity. Gastric emptying of solid or liquid with oesophageal infusion was not significantly different from that with gastric infusion.

CONCLUSIONS

These findings support the hypothesis of the existence of a physiological oesophago-gastric feedback mechanism that might contribute to regulation of postprandial gastric acidity. Oesophageal acidification might decode gastric information and signal the stomach to decrease gastric acidity. Further studies are needed to assess the characteristics of such feedback mechanism in-patients with gastro-oesophageal reflux disease (GERD).

Response rate and predictors of response in a short-term empirical trial of high-dose rabeprazole in patients with globus

BACKGROUND

Although the aetiology of globus (the sensation of a lump in the throat) remains unclear, gastro-oesophageal reflux disease is associated with globus. A short-term trial with a high-dose proton pump inhibitor has been shown to be a sensitive tool for diagnosing gastro-oesophageal reflux disease.

AIM

To see whether patients with globus symptom responded to short-term high-dose rabeprazole trial and assess predictors of symptom response.

METHODS

Sixty-four patients with globus symptom were analysed. Patients received rabeprazole 20 mg b.d. for 14 days. Patients completed a daily diary assessing the severity and frequency of globus.

RESULTS

Forty-one patients (64%) were diagnosed clinically with gastro-oesophageal reflux disease. Based on the pH testing and endoscopy, the prevalence of gastro-oesophageal reflux disease was 22% (14 of 64). The globus symptom score was significantly higher in patients with gastro-oesophageal reflux disease compared with patients without gastro-oesophageal reflux disease (P = 0.004). Two patients (3%) had complete resolution and 22 (34%) had more than a 50% improvement in the globus symptom score. Endoscopic findings (P = 0.714), pathological acid exposure on pH testing (P = 0.741) or baseline gastro-oesophageal reflux disease symptoms (P = 0.606) were not associated with improvement of globus symptom.

CONCLUSION

While gastro-oesophageal reflux disease may be an aggravating factor in patients with globus, it does not appear to be the sole cause of globus symptom.

H pylori eradication: A randomized prospective study of triple therapy with or without ecabet sodium

AIM: To investigate whether adding ecabet sodium to the standard triple therapy for H pylori infection improve eradication rate.

METHODS: Two hundred and fifty-seven H pylori-infected patients were randomly assigned to standard triple therapy (group A, n = 129) or triple therapy plus ecabet sodium (group B, n = 128). Successful eradication was defined as a negative ¹³C-urea breath test 6-8 wk after completion of treatment.

RESULTS: After completion of therapy, 194/257 patients showed negative ¹³C-urea breath test results. According to intention-to-treat analysis, the infection was eradicated in 93/129 (72.1%) patients in group A and 101/128 (78.9%) in group B (P = 0.204). Per-protocol analysis showed successful eradication in 93/118 (78.8%) patients from group A and 101/114 (88.6%) from group B (P = 0.044). There were no significant differences in the side effects experienced by the patients in the two treatment groups.

CONCLUSION: Our results suggest that the addition of ecabet sodium improves the efficacy of the standard triple therapy for H pylori.

Comparison of the effects of single and repeated oral doses of lansoprazole and rabeprazole on ambulatory 24-hour intragastric pH in healthy volunteers

BACKGROUND

As the comparative pharmacokinetics and pharmacodynamics of lansoprazole and rabeprazole have not previously been studied, we set out in this study to compare the pharmacokinetics and pharmacodynamics of single and repeated daily doses of lansoprazole 15 mg and 30 mg with those of rabeprazole 10 mg and 20 mg.

METHODS

This was an open-label, randomised, crossover, two-centre study in 72 healthy volunteers. Each subject received each of the four treatments for 5 days, with 2-week washout periods. Continuous 24-hour intragastric pH and pharmacokinetics were studied on days 1 and 5.

RESULTS

Mean 24-hour pH and percentage time for pH > 4 were not significantly different between lansoprazole 30 mg and rabeprazole 20 mg. Mean 24-hour pH and percentage time for pH > 4 were significantly greater after lansoprazole 30 mg and rabeprazole 20 mg than after lansoprazole 15 mg and rabeprazole 10 mg, respectively. Lansoprazole resulted in greater acid suppression during hours 0-5 on days 1 and 5, whereas rabeprazole had greater suppression during hours 11-24 on day 5. Time to maximum plasma concentration was significantly shorter for lansoprazole on both days.

CONCLUSION

Lansoprazole had a consistently faster onset of action, whereas rabeprazole had a greater effect during the evening hours after 5 days of administration.

What is potent acid inhibition, and how can it be achieved?

The clinical response to antisecretory treatment correlates directly with the degree of inhibition of acid secretion achieved. Acid inhibition able to maintain the intragastric pH at a value greater than 4 for at least 16 h/day seems to heal even the most refractory acid-related diseases. It has also been shown that the degree of inhibition of acid secretion in response to antisecretory treatment depends on the genetic characteristics of the patient and on the presence of Helicobacter pylori infection. A possible definition of potent (or profound) acid inhibition is, therefore, the achievement of the aforementioned level of control of acid secretion regardless of patient characteristics or of the presence of H. pylori infection. Antisecretory drugs differ in their ability to reach potent acid inhibition. As far as the comparative efficacy of different drugs for inhibiting acid secretion is concerned, proton pump inhibitors are more efficient in inhibiting gastric acid secretion than histamine (H2) receptor antagonists. Among the different proton pump inhibitors, esomeprazole 40 mg/day exhibits greater antisecretory potency than the others at standard doses. Rabeprazole 20 mg/day and lansoprazole 30 mg/day exhibit a more rapid onset of action than omeprazole 20 mg/day or pantoprazole 40 mg/day.

Frequency analyses of gastric pH in control and gastro-oesophageal reflux disease subjects treated with a proton-pump inhibitor

BACKGROUND

We are unaware of any solid theoretical or pathophysiological basis for selecting pH 4 or any other pH value to assess gastric acidity.

AIM

To examine the frequency of different gastric pH values in control and GERD subjects.

METHODS

Gastric pH was measured for 24 h in 26 control subjects, 26 gastro-oesophageal reflux disease subjects at baseline and the same 26 gastro-oesophageal reflux disease subjects during treatment with a proton-pump inhibitor. Histograms were constructed using the 21 600 values generated from each recording and bins of 0.25 pH units.

RESULTS

The distribution of gastric pH values in gastro-oesophageal reflux disease subjects was significantly different from that in controls and in some instances the distributions detected significant differences that were not detected by integrated acidity. Proton-pump inhibitor treatment significantly altered the distribution of gastric pH values and the nature of this alteration during the postprandial period was different from that during the nocturnal period. Using time pH< or =4 can significantly underestimate the magnitude of inhibition of gastric acidity caused by a proton-pump inhibitor.

CONCLUSIONS

The distribution of gastric pH values provides a rationale for selecting a particular pH value to assess gastric acidity. In some instances, the distribution of gastric pH values detects significant differences between gastro-oesophageal reflux disease and normal subjects that are not detected by integrated acidity.

Masking of 13C urea breath test by proton pump inhibitors is dependent on type of medication: comparison between omeprazole, pantoprazole, lansoprazole and esomeprazole

BACKGROUND

The need to withhold acid suppression therapy while awaiting urea breath test results is a common clinical problem in symptomatic patients. It is unclear at present if the dose or type of proton pump inhibitor or the type of test meal govern the apparent masking effect of proton pump inhibitors on the urea breath test.

AIM

To prospectively evaluate Helicobacter pylori detection rates during treatment with four different proton pump inhibitors, utilizing a high-dose citric acid-based 13C urea breath test.

METHODS

Patients positive for Helicobacter pylori by urea breath test were randomized to receive either omeprazole 20 mg/day, pantoprazole 40 mg/day, lansoprazole 30 mg/day or esomeprazole 40 mg/day for 14 days. A repeat breath test was performed on day 14 of treatment.

RESULTS

One hundred and seventy-nine patients, mean age 45.8 +/- 16.8, completed the study. Treatment with omeprazole or pantoprazole prior to urea breath test (UBT) was associated with low false negative results, while lansoprazole and esomeprazole caused clinically unacceptable high false negative rates (pantoprazole 2.2% vs. lansoprazole 16.6%, P = 0.02, vs. esomeprazole 13.6%, P = 0.05; omeprazole 4.1% vs. lansoprazole 16.6%, P = 0.05).

CONCLUSIONS

Proton pump inhibitor-induced false negative results on high-dose citric acid based urea breath test vary with the type of proton pump inhibitor used. Selection of the appropriate test meal and proton pump inhibitor may allow symptomatic individuals to continue their proton pump inhibitors prior to performing a urea breath test.

Tenatoprazole, a novel proton pump inhibitor with a prolonged plasma half-life: effects on intragastric pH and comparison with esomeprazole in healthy volunteers

BACKGROUND

Proton pump inhibitors control gastric acidity better during the day than at night, when nocturnal acid breakthrough can occur. Tenatoprazole is a novel proton pump inhibitor with a seven-fold longer plasma half-life. Aim : To compare the effects of tenatoprazole 20 mg (T20), tenatoprazole 40 mg (T40) and esomeprazole 40 mg (E40) on intragastric acidity in healthy volunteers.

METHODS

This randomized, three-period, cross-over study enrolled 18 Helicobacter pylori-negative volunteers, who received E40, T20 and T40 once daily for 7 days with a 14-day washout between periods. Twenty-four-hour gastric pH monitoring was performed on day 7. Serum gastrin was assessed on day 8.

RESULTS

T40 induced a more potent acid inhibition than T20 (24-h median pH: 4.6 vs. 4.0, P < 0.01; daytime: 4.5 vs. 3.9, P < 0.01; night-time: 4.7 vs. 4.1, P < 0.05). T40 was more potent than E40 (24-h median pH: 4.6 vs. 4.2, P < 0.05; night-time: 4.7 vs. 3.6, P < 0.01); the pH > 4 holding time was higher during the night for T40 than for E40: 64.3% vs. 46.8%, P < 0.01; the nocturnal acid breakthrough duration was significantly shorter for T40 than for E40. No significant gastrin increase was observed and all drugs were well tolerated.

CONCLUSION

T40 is significantly more potent than T20 and E40 during the night. The therapeutic relevance of this pharmacological advantage deserves further study.

Comparative pharmacokinetics and safety of lansoprazole oral capsules and orally disintegrating tablets in healthy subjects

BACKGROUND

Many individuals with acid-related gastrointestinal disorders have difficulty in swallowing oral agents.

AIM

To compare the bio-availability of a single dose of lansoprazole orally disintegrating tablet with that of an intact capsule.

METHODS

One hundred and twenty healthy subjects participated in two prospective, Phase I, open-label, two-period cross-over studies to receive lansoprazole, 15 mg or 30 mg. Within each study, subjects were randomized into two parallel cohorts consisting of 30 subjects per regimen, dispensed in opposing sequence over two periods separated by a 7-day washout period. Blood samples were collected on day 1 of both periods to determine the pharmacokinetic parameters.

RESULTS

Tmax occurred at 1.8 and 2.0 h with the 15-mg and 30-mg tablets, respectively. Dose proportional increases in Cmax, AUCt and AUC infinity were observed in the 15-mg and 30-mg groups. The terminal elimination half-lives (t1/2) were identical in both dose groups (1.18 h). Lansoprazole administered as the orally disintegrating tablet was bio-equivalent to the intact capsule formulation with respect to Cmax, AUCt and AUC infinity.

CONCLUSIONS

Lansoprazole orally disintegrating tablets, 15 mg and 30 mg, are bio-equivalent to the respective dose administered as the intact capsule. This novel dosage formulation represents an option for patients who have difficulty in swallowing oral agents.

Effects of rabeprazole, lansoprazole and omeprazole on intragastric pH in CYP2C19 extensive metabolizers

AIM

To investigate the inhibitory effects on gastric acid secretion of three proton pump inhibitors, omeprazole, lansoprazole and rabeprazole, using a three-way crossover design in healthy Helicobacter pylori-negative,S-mephenytoin 4'-hydroxylase (CYP2C19) homo- and hetero-extensive metabolizers.

METHODS

Eight healthy Japanese male volunteers were enrolled. After the administration of rabeprazole (10 mg/day), lansoprazole (30 mg/day) or omeprazole (20 mg/day), intragastric pH monitoring was commenced from 24 h before the first proton pump inhibitor dose, and continued for days 1-3 after proton pump inhibitor administration. The pH electrode was used for 48 h and changed just before pH monitoring on day 2.

RESULTS

For the administration of 10 mg/day rabeprazole, the mean ratios of the 24-h pH > or = 3 holding time were 5.7 +/- 1.1%,13.6 +/- 2.2%, 35.3 +/- 2.7% and 62.8 +/- 3.1% for the pre-treatment day and days 1, 2 and 3, respectively. The same ratios for lansoprazole (30 mg/day) were 5.7 +/- 0.7%, 7.4 +/- 1.5%, 13.6 +/- 3.4% and 26.6 +/- 4.9%; the same ratios for 20 mg/day omeprazole were 5.9 +/- 0.9%, 6.1 +/- 1.2%, 11.4 +/- 2.8% and 16.4 +/- 4.6%. The mean ratio of the 24-h pH > or = 3 holding time of days 1-3 increased significantly compared to the pre-treatment day (P < 0.01) with the administration of rabeprazole and lansoprazole. The magnitude of inhibition of gastric acid secretion after rabeprazole administration was stronger than that after lansoprazole. A significant elevation of the mean ratio of the 24-h pH > or = 3 holding time was demonstrated on days 2 and 3 with omeprazole (P < 0.01).

CONCLUSIONS

In H. pylori-negative CYP2C19 extensive metabolizers, rabeprazole (10 mg/day) shows a faster onset of rising intragastric pH and a stronger inhibition of gastric acid secretion than do lansoprazole (30 mg/day) or omeprazole (20 mg/day).

Acid suppression in healthy subjects following lansoprazole or pantoprazole

AIM

To compare the effect of lansoprazole, 30 mg once daily, with that of pantoprazole, 40 mg once daily, for the inhibition of gastric acid secretion.

METHODS

Two randomized, single-blind, two-way, crossover studies were conducted in 74 healthy male volunteers. Lansoprazole, 30 mg, or pantoprazole, 40 mg, was administered once daily for five consecutive days with at least a 2-week washout period between regimens. Ambulatory 24-h intragastric pH was recorded at baseline and on days 1 and 5 of each crossover treatment period.

RESULTS

On day 1 in both studies, lansoprazole, 30 mg, produced significantly higher mean 24-h intragastric pH values when compared to pantoprazole, 40 mg (3.78 vs. 3.08, P < 0.001, and 3.97 vs. 3.20, P < 0.001, in the first and second studies, respectively). In both studies, lansoprazole, 30 mg, produced significantly greater proportions of time that the intragastric pH was above 3, 4 and 5 when compared with pantoprazole, 40 mg (P < 0.005 in all comparisons). By treatment day 5 in the first study, lansoprazole, 30 mg, continued to produce a higher mean 24-h intragastric pH (4.15 vs. 3.91, P=0.014) and a significantly greater percentage of time that the intragastric pH was above 4 (63% vs. 56%, P=0.017) and 5 (41% vs. 30%, P < 0.001) when compared with pantoprazole, 40 mg. In the second study, the effects on intragastric pH were comparable between the two treatment groups. Headache was the most commonly reported adverse experience (nine lansoprazole-treated subjects, seven in the first study and two in the second study; six pantoprazole-treated subjects, five in the first study and one in the second study).

CONCLUSIONS

Lansoprazole, 30 mg once daily, produces a faster onset and greater degree of acid inhibition than pantoprazole, 40 mg once daily. The implications for these differences on symptom relief and healing of erosive oesophagitis should be explored.

Integrated acidity and rabeprazole pharmacology

BACKGROUND

Integrated gastric and oesophageal acidity can be calculated from measurements of gastric and oesophageal pH and used to quantify gastric and oesophageal acidity over time. Rabeprazole is a new proton pump inhibitor that is effective in treating gastro-oesophageal reflux disease (GERD).

AIM

To use measurement of integrated gastric and oesophageal acidity to determine the onset, duration and overall effect of rabeprazole in subjects with GERD.

METHODS

Subjects with GERD were required to have oesophageal pH less-than-or-equal 4 for at least 10% of a 24-h recording. Effects of 20 mg rabeprazole on 24-h gastric and oesophageal pH were measured on days 1 and 7 of dosing. Integrated gastric and oesophageal acidity were calculated from time-weighted average hydrogen ion concentrations at each second of the 24-h record.

RESULTS

At steady-state, 20 mg rabeprazole inhibited gastric acidity by 89% and oesophageal acidity by 95%. The first dose of rabeprazole inhibited gastric and oesophageal acidity by at least 70% of the steady-state effect. Oesophageal acidity could be divided into monophasic and biphasic patterns, and rabeprazole had different effects on oesophageal and gastric acidity in these two GERD subpopulations. The onset of action of the first dose of rabeprazole on gastric acidity was 4 h and on oesophageal acidity was 4 h in monophasic subjects and 7 h in biphasic subjects. Integrated acidity was more sensitive than time pH less-than-or-equal 4 in measuring the inhibitory actions of rabeprazole.

CONCLUSIONS

Integrated gastric and oesophageal acidity are quantitative measurements that provide useful and novel information regarding the pathophysiology of GERD as well as the impact of antisecretory agents such as rabeprazole.

A comparison of simplified lansoprazole suspension administered nasogastrically and pantoprazole administered intravenously: effects on 24-h intragastric pH

AIM

To compare the 24-h intragastric pH effects of simplified lansoprazole suspension, 30 mg, administered nasogastrically, with pantoprazole, 40 mg, administered intravenously.

METHODS

Thirty-six healthy adults were enrolled and given simplified lansoprazole suspension, 30 mg (nasogastrically), or pantoprazole, 40 mg (intravenously), once daily for five consecutive days in a cross-over fashion. Intragastric pH was monitored at baseline and on Days 1 and 5 of each treatment period. The pharmacokinetic parameters of lansoprazole and pantoprazole were also determined on Days 1 and 5.

RESULTS

No statistically significant changes in pharmacokinetic parameters occurred between Days 1 and 5 with either regimen, except for pantoprazole Cmax. On Days 1 and 5, significantly higher mean 24-h intragastric pH values were observed with 30 mg simplified lansoprazole suspension compared with 40 mg intravenous pantoprazole (Day 1, 3.13 vs. 2.67; Day 5, 3.95 vs. 3.61, respectively; P < 0.05). Additionally, 30 mg simplified lansoprazole suspension produced significantly (P < 0.05) higher percentages of time intragastric pH was above 3, 4, 5 or 6 as compared with 40 mg intravenous pantoprazole throughout Days 1 and 5.

CONCLUSIONS

A 30 mg dose of simplified lansoprazole suspension administered nasogastrically was consistently more effective at controlling intragastric pH than pantoprazole, 40 mg, administered intravenously.

Lansoprazole in children: pharmacokinetics and efficacy in reflux oesophagitis

BACKGROUND

Data on the proton pump inhibitor lansoprazole in paediatric patients are limited.

AIM

To investigate the pharmacokinetics, optimal dosage and efficacy of lansoprazole in paediatric patients.

METHODS

A 24-h gastric pH recording and a pharmacokinetic study were performed after 7 days of lansoprazole, 17 mg/m2, in 23 patients with reflux oesophagitis (median age, 3.5 years). Response was defined as pH > 3 for > 65% of the recording. The dosage was doubled in non-responders. Patients with no response on day 14 were excluded. Responders underwent endoscopy after 4 weeks on the response-inducing dosage; abnormal findings led to a repeat endoscopy after four additional weeks.

RESULTS

Nine patients responded to 17 mg/m2 and six to 30.3 mg/m2. On day 7, time with pH > 3 was significantly correlated with the area under the plasma concentration-time curve (P=0.003). The area under the plasma concentration-time curve was significantly greater in the nine responders to 17 mg/m2 than in the 14 other patients. Pharmacokinetic parameters were similar in responders and non-responders to the higher dose. After 4 weeks, oesophagitis was healed in 80% of responders. Adverse events occurred in three patients and required treatment discontinuation in one.

CONCLUSIONS

Lansoprazole is effective and safe in children. The optimal starting dosage is 30 mg/m2 or 1.4 mg/kg.

Effects on 24-hour intragastric pH: a comparison of lansoprazole administered nasogastrically in apple juice and pantoprazole administered intravenously

OBJECTIVE

To compare the 24-h intragastric pH effects of lansoprazole, 30 mg administered nasogastrically, with pantoprazole, 40 mg administered i.v.

METHODS

Healthy adults were enrolled in an open label, two-way crossover, single-center study. Thirty milligrams of lansoprazole (administered nasogastrically in apple juice) or pantoprazole (i.v.) were administered once daily at 8:00 AM for 5 consecutive days with at least a 2-wk washout period between the regimens. Ambulatory 24-h intragastric pH was monitored at baseline and on days 1 and 5 of each treatment period. Blood specimens were collected on days I and 5 for pharmacokinetic parameter determinations.

RESULTS

Thirty-three adults completed both crossover periods, with the exception of one patient with a zero lansoprazole plasma concentration on day 1 of period 2. Lansoprazole, 30 mg per nasogastric tube, produced significantly higher mean 24-h intragastric pH values relative to pantoprazole, 40 mg i.v., on both day 1 (3.05 vs 2.76, p < 0.002) and day 5 (3.65 vs 3.45, p = 0.024). Lansoprazole sustained the intragastric pH above 3 (days 1 and 5), 4, and 5 (day 1) significantly longer relative to pantoprazole. Lansoprazole's time to the maximum observed concentration and area under the plasma concentration-time curve over the 24-h time interval increased significantly from day I to day 5 (1.7 h vs 2.0 h and 1865 ng x h/ml vs 2091 ng x h/ml, respectively), and a significant increase in half-life relative to day 1 (0.96 h) was observed on day 5 (1.03 h) during pantoprazole treatment.

CONCLUSION

Lansoprazole, 30 mg administered nasogastrically, effectively controls intragastric pH and is an alternative to i.v. pantoprazole in patients who are unable to swallow solid dosage formulations.

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.

Control of intragastric pH with omeprazole 20 mg, omeprazole 40 mg and lansoprazole 30 mg

BACKGROUND

Single daily doses of proton pump inhibitors, omeprazole and lansoprazole provide effective acid suppression and equal healing and symptom relief in patients with GERD. Despite this, controversy exists as to the efficacy of available proton pump inhibitors in the control of gastric acidity.

AIM

To assess the efficacy of omeprazole 20 mg vs. lansoprazole 30 mg and omeprazole 40 mg vs. lansoprazole 30 mg in intragastric pH control.

METHODS

Study I: 12 Helicobacter pylori-negative volunteers (mean age 33 years) were treated with omeprazole 20 mg and lansoprazole 30 mg in random order before breakfast for 7 days. Study II: 24 subjects (mean age 36 years) were similarly treated with omeprazole 40 mg and lansoprazole 30 mg for 7 days after a baseline pH study. One week washout was allowed between studies. Subjects had the same meal on each study day. On day seven, a 24-h intragastric pH study was performed. The percentage time for which gastric pH > 4 was analysed (Gastrosoft, Synectics Medical Inc.) and expressed as mean +/- s.d.

RESULTS

(1) Omeprazole 20 mg and lansoprazole 30 mg showed no significant difference in the percentage time for which gastric pH > 4 in the daytime and night-time periods. (2) The percentage time for which pH > 4 with omeprazole 40 mg was significantly greater than lansoprazole 30 mg in both daytime (61 +/- 19% vs. 48 +/- 14%, P < 0.001), and night-time periods (34 +/- 21% vs. 26 +/- 14%, P < 0.05). (3) A large inter-subject variation existed in both studies. (4) In 10 subjects who participated in both studies, omeprazole 40 mg showed a significantly higher percentage time for which pH > 4 in the daytime (69 +/- 18% vs. 51 +/- 15%, P=0.015) than omeprazole 20 mg.

CONCLUSION

These pH data support the therapeutic equivalency of FDA approved doses of omeprazole and lansoprazole.

Review article: comparison of the pharmacokinetics, acid suppression and efficacy of proton pump inhibitors

Proton pump inhibitors have dramatically influenced the management of acid-peptic disorders in recent years. They all have a broadly similar mechanism of action and are extensively metabolized in the liver via cytochromes P450 2C19 and 3A4. There is some variation in their potential for drug interactions due to differences in enzyme inhibition. Relatively few serious adverse effects have been reported for the proton pump inhibitors. Comparative studies of acid suppression suggest that lansoprazole and pantoprazole have a potency similar to that of omeprazole on a mg for mg basis; however, rabeprazole may have a greater potency than omeprazole. Lansoprazole and rabeprazole display a more rapid onset of maximal acid suppression than the other proton pump inhibitors. Comparative studies using proton pump inhibitors for the treatment of reflux oesophagitis, duodenal ulcer healing and Helicobacter pylori eradication show little overall difference in outcome between the proton pump inhibitors when used in their standard doses. Lansoprazole and rabeprazole provide earlier and better symptom relief than the other proton pump inhibitors in some studies of peptic ulcer treatment. The few studies of gastric ulcer treatment suggest that there is an advantage in using the proton pump inhibitors that have a higher standard daily dose.

Clinical and fiscal impact of lansoprazole intolerance in veterans with gastro-oesophageal reflux disease

BACKGROUND

Omeprazole was replaced by lansoprazole as the only proton pump inhibitor on the Veterans Affairs (VA) formulary in February 1997. We aimed to assess the clinical and fiscal impact of this conversion at two VA hospitals.

METHODS

We identified lansoprazole intolerant patients using pharmacy databases. We reviewed medical records to obtain data regarding reasons for lansoprazole intolerance. The costs of the formulary change and the savings to the VA were calculated.

RESULTS

A total of 3833 patients required long-term proton pump inhibitor therapy; 2224 (58%) were started on lansoprazole and 1479 (39%) were converted from omeprazole to lansoprazole. The remaining 130 (3.4%) patients were never converted from omeprazole to lansoprazole. Of the 3833 patients, 325 (8.5%) currently receive omeprazole therapy; of these, 195 out of 3703 (5.3%) patients are true lansoprazole failures; 172 of these 195 patients completed the study. Most (87%) of the lansoprazole intolerant patients received prior omeprazole. Discontinuation of lansoprazole was due to poor symptom control in 69% and/or side-effects (22%) including diarrhoea (10%), abdominal pain (5%), or hives (1%). The 1-year cost of managing lansoprazole failure in 195 patients was $61 690. However, the savings to the VA during the same time period, which totalled $321 360, more than offset the costs associated with the conversion.

CONCLUSIONS

Lansoprazole intolerance requiring omeprazole conversion occurred in 5% of veterans on proton pump inhibitor therapy for chronic gastro-oesophageal reflux disease (GERD) symptoms and in 10% of patients with prior omeprazole success. The VA realized substantial cost savings in association with the formulary change.

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

BACKGROUND

Systematic, randomized, and controlled studies on the effect of low to high doses of the proton pump inhibitor lansoprazole on intragastric acidity and plasma gastrin levels have not previously been performed.

METHODS

We investigated the effect of 7-day therapy with different doses of lansoprazole (15 mg once or twice daily, 30 mg once or twice daily, and 15 mg three times daily) on intragastric acidity and meal-stimulated daytime plasma gastrin levels in 12 healthy Helicobacter pylori-negative human subjects in a randomized, double-blind, placebo-controlled, 6-way crossover study. On days 1, 2, and 7 of the study 24-h intragastric pH-metry and 12-h integrated daytime plasma gastrin determinations were done.

RESULTS

Lansoprazole in a dose regimen of 1 x 30 mg/day, 3 x 15 mg/daily, and 2 x 30 mg/day significantly (P < 0.05) increased the intragastric 24-h median pH on days 1, 2, and 7 of therapy as compared with placebo. Lansoprazole in doses of 1 x 15 mg/day and 2 x 15 mg/day significantly increased the intragastric 24-h median pH on days 2 and 7 but not on day 1 of therapy. Doses of 3 x 15 mg and 2 x 30 mg lansoprazole daily significantly increased the intragastric 24-h median pH on days 2 and 7 of treatment as compared with 1 x 30 mg lansoprazole daily. Except for 1 x 15 mg lansoprazole on day 1 of therapy, all given dose regimens of lansoprazole (15-60 mg/day) significantly (P < 0.05) stimulated the 12-h integrated meal-stimulated daytime plasma gastrin response (pM x min) on days 1, 2, and 7 of therapy as compared with placebo.

CONCLUSION

A dose of 1 x 30 mg/day is nearly as potent as higher dose regimens of lansoprazole. Thus it most likely is the optimum dose for therapy of gastric and duodenal peptic lesions. A dose of 1 x 15 mg lansoprazole daily is a potent inhibitor of gastric acid output and could be a therapeutic dose for prevention of peptic lesions (that is, reflux oesophagitis or ulcers).

Eradication of Helicobacter pylori with lansoprazole, roxithromycin and metronidazole--an open pilot study

BACKGROUND

The most extensively studied Helicobacter pylori eradication regimen comprises omeprazole, clarithromycin and metronidazole. Macrolide antibiotics other than clarithromycin should achieve similar efficacy, but they have not yet been thoroughly tested.

AIM

To determine the efficacy and safety of a triple therapy regimen using lansoprazole, roxithromycin, and metronidazole on the basis of multicentre outpatient care in an open pilot study.

METHODS

163 patients with duodenal ulcer and proven H. pylori infection received lansoprazole 30 mg b.d., roxithromycin 300 mg b.d. and metronidazole 500 mg b.d. for 7 days followed by another 7 days of lansoprazole 30 mg once daily. H. pylori status was determined by urease quick test, histology, microbiology and 13C-urea breath test before starting and at least 4 weeks after completing treatment.

RESULTS

150 patients were available for evaluation; H. pylori was successfully eradicated in 84.7% (127/ 150) as determined by urease quick test, 78.0% (117/150) by histology, 81.3% (109/134) by 13C-urea breath test; and in 75.3% (113/150), at least two tests were negative. Side-effects were reported in 34 patients (most commonly diarrhoea and changes in liver function tests), in two cases the study medication was interrupted. Prior to treatment, 23% of the H. pylori isolates were resistant against metronidazole and 3.4% against roxithromycin. After unsuccessful treatment, 84% of the isolates were resistant against metronidazole and 21% against roxithromycin. Primary resistance to metronidazole increased the chance of treatment failure approximately sevenfold (7% vs. 53%).

CONCLUSIONS

For H. pylori eradication, the combination of lansoprazole, roxithromycin and metronidazole proved to be as safe as other current triple therapy regimens, while a comparison of efficacy rates yet remains to be assessed in prospective controlled trials. The metronidazole-resistant H. pylori is not rare in Germany and, in the present study, has strongly influenced treatment success.

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.

Proton pump inhibitors. Pharmacology and rationale for use in gastrointestinal disorders

Proton pump inhibitors (PPIs) are drugs which irreversibly inhibit proton pump (H+/K+ ATPase) function and are the most potent gastric acid-suppressing agents in clinical use. There is now a substantial body of evidence showing improved efficacy of PPIs over the histamine H2 receptor antagonists and other drugs in acid-related disorders. Omeprazole 20 mg/day, lansoprazole 30 mg/day, pantoprazole 40 mg/day or rabeprazole 20 mg/day for 2 to 4 weeks are more effective than standard doses of H2-receptor antagonists in healing duodenal and gastric ulcers. Patients with gastric ulcers should receive standard doses of PPIs as for duodenal ulcers but for a longer time period (4 to 8 weeks). There is no conclusive evidence to support the use of a particular PPI over another for either duodenal or gastric ulcer healing. For Helicobacter pylori-positive duodenal ulceration, a combination of a PPI and 2 antibacterials will eradicate H. pylori in over 90% of cases and significantly reduce ulcer recurrence. Patients with H. pylori-positive gastric ulcers should be managed similarly. PPIs also have efficacy advantages over ranitidine and misoprostol and are better tolerated than misoprostol in patients taking nonsteroidal anti-inflammatory drugs (NSAIDs). In endoscopically proven gastro-oesophageal reflux disease, standard daily doses of the PPIs are more effective than H2-receptor antagonists for healing, and patients should receive a 4 to 8 week course of treatment. For severe reflux, with ulceration and/or stricture formation, a higher dose regimen (omeprazole 40 mg, lansoprazole 60 mg, pantoprazole 80 mg or rabeprazole 40 mg daily) appears to yield better healing rates. There is little evidence that PPIs lead to resolution of Barrett's oesophagus or a reduction of subsequent adenocarcinoma development, but PPIs are indicated in healing of any associated ulceration. In Zollinger-Ellison syndrome, PPIs have become the treatment of choice for the management of gastric acid hypersecretion.

Prospective evaluation of a new anti-ulcer agent, ecabet sodium, for the treatment of Helicobacter pylori infection

BACKGROUND

A new anti-ulcer agent, ecabet sodium, is active against Helicobacter pylori.

AIM

To assess the efficacy of ecabet sodium for the eradication of H. pylori in patients with gastroduodenal diseases.

METHODS

In a prospective, randomized and controlled study, patients infected with H. pylori were assigned to one of the following two groups: group LA, who received lansoprazole 30 mg o.d. + amoxycillin 500 mg q.d.s. after meals for 2 weeks, and group LAE, who received lansoprazole 30 mg o.d. + amoxycillin 500 mg q.d.s. + ecabet sodium 1000 mg b.d. after meals for 2 weeks. H. pylori status was determined before and at least 4 weeks after the therapy by rapid urease test, histology and a urea breath test.

RESULTS

Of 101 patients (mean age 53 years, range 17-77 years, M/F: 68/33) enrolled in the study, 97 patients completed the protocol. Four patients were withdrawn because of diarrhoea (three from group LA) and skin rash (one from group LAE). The eradication of H. pylori was achieved in 28/48 (58%) patients in group LA and 38/49 (78%) patients in group LAE. The rate of eradication of H. pylori produced by the LAE treatment was significantly higher than that produced by the LA treatment. Side-effects appeared in two patients (malaise 1, skin rash 1) in group LAE and in seven patients (diarrhoea 6, dizziness 1) in group LA. These side effects disappeared spontaneously with cessation of the treatment.

CONCLUSIONS

Ecabet sodium in combination with lansoprazole and amoxycillin increased the rate of eradication of H. pylori. Ecabet sodium appeared to reduce the incidence of diarrhoea as a side-effect of the dual LA therapy.

Acid-inhibitory effects of omeprazole and lansoprazole in Helicobacter pylori-negative healthy subjects

BACKGROUND

Omeprazole 20 mg once daily (o.d.) and lansoprazole 30 mg o.d. have similar acid-inhibitory effects in healthy Helicobacter pylori-positive subjects. However, little is known about the acid-inhibitory effects of the o.d. and twice daily (b.d.) doses in H. pylori-negative subjects.

AIM

To compare the decrease in gastric acidity of omeprazole 20 mg (o.d. and b.d.) with lansoprazole 30 mg (o.d. and b.d.) in healthy H. pylori-negative subjects on day 6-7 of dosing.

METHODS

A randomized, investigator-blind, crossover study design was used. Intragastric pH was measured continuously with glass electrodes positioned in the gastric corpus. Sixteen H. pylori-negative subjects, whose intragastric acidity fell below pH 4 for 70% of a 24-h baseline period. were entered in the study.

RESULTS

Both dosing regimens of omeprazole and lansoprazole significantly increased median gastric pH and percentages of time above pH 4 during the entire 24-h period, night- and daytime, compared to baseline. There were no significant differences in median gastric pH values or time above pH thresholds 3, 4 and 5 between the o.d. dosing regimens. During the night the percentage of time spent above pH 3 and 4 was significantly higher with omeprazole 20 mg b.d. than with lansoprazole 30 mg b.d.

CONCLUSIONS

This comparative study demonstrates that daily doses of omeprazole 20 mg and lansoprazole 30 mg are equally effective in raising intragastric pH in H. pylori-negative subjects on day 6 of dosing. During the night, omeprazole 20 mg b.d. provides superior gastric acid suppression compared to lansoprazole 30 mg b.d.

The comparative effects of lansoprazole, omeprazole, and ranitidine in suppressing gastric acid secretion

The effects on 24-hour intragastric pH levels of once-daily doses of lansoprazole 15 mg and lansoprazole 30 mg were compared with the effects of omeprazole 20 mg QD and ranitidine 150 mg QID in a phase I, randomized, double-masked, four-way crossover study conducted in 29 healthy male volunteers. Subjects received each treatment regimen for 5 consecutive days with at least a 2-week washout between treatment periods. Ambulatory 24-hour intragastric pH values were monitored in each subject at baseline (2 days before crossover period 1) and again before dosing on day 5 of each of the four crossover treatment periods. Gastric pH values increased during all four regimens, with significantly higher mean 24-hour pH values noted in subjects receiving lansoprazole 30 mg QD (4.53 +/- 0.16) compared with those receiving lansoprazole 15 mg QD (3.97 +/- 0.16), omeprazole 20 mg QD (4.02 +/- 0.16), or ranitidine 150 mg QID (3.59 +/- 0.16). Lansoprazole 30 mg produced significantly greater mean percentages of time that the gastric pH was above 3.0 and 4.0 (75% and 63%, respectively) compared with the other treatment regimens. The mean percentages of time during which gastric pH was above 3.0 and 4.0, respectively, for the other treatments were lansoprazole 15 mg, 64% and 48%; omeprazole 20 mg, 63% and 51%; and ranitidine 150 mg, 52% and 38%. All treatment regimens were well tolerated, with no clinically significant differences between the regimens. Multiple-dose lansoprazole 30 mg QD produced a significantly increased intragastric pH level and significantly longer durations of increased intragastric pH level compared with lansoprazole 15 mg QD, omeprazole 20 mg QD, and ranitidine 150 mg QID.

24-hour recording of intragastric pH in clinical trials: preconditions, methodology, and standardization strategies

At present, intragastric pH recording by stomach probe is the standard method for the assessment of the pharmacodynamic effect of newly developed antisecretory drugs, and it is being used increasingly as a diagnostic method. Intraluminal pH can be measured by a variety of different electrode systems, systematic differences among these systems require international standardization of the method. In clinical trials, some recommendations should be followed to standardize the study conditions to assure that repeated measurements are comparable. Standardization of food and liquid intake and a correct positioning of the stomach probe are of paramount importance in assuring that the data are reliable; but there are other factors that may influence the study results, for example, the daily activities of the study participants and the method of data processing. Furthermore, several technical aspects must be considered to guarantee accurate and reproducible recordings, including the type of pH-sensitive electrode and the method of calibration used. Further efforts should be made to create an international standard for the method to assure more comparable study results.

Gastric antisecretory activity of lansoprazole in different experimental models: comparison with omeprazole

1. The activity of the novel proton pump with inhibitor lansoprazole was examined in different gastric secretion models in vitro and in vivo, in comparison with omeprazole. 2. In the conscious cat with gastric fistula lansoprazole (0.25-2 mumol/kg i.v.) caused a dose-dependent reduction of the acid secretion induced by dimaprit, pentagastrin, 2-deoxy-D-glucose and bombesin, being approximately as potent as omeprazole (0.25-1.5 mumol/kg i.v.). Similar to omeprazole, lansoprazole was also more effective when administered in hyperacidic states. 3. In the anaesthetized rat with lumen perfused stomach lansoprazole (0.03-1 mumol/kg i.v.) was approximately 3 times more potent than omeprazole (0.1-3 mumol/kg i.v.) in inhibiting the acid secretion induced by histamine, 2-deoxy-D-glucose and forskolin. 4. In the isolated gastric fundus from the immature rat lansoprazole (1-30 microM) reduced basal acid secretion and the acid response to histamine and forskolin, with a potency not significantly different from that of omeprazole. 5. No significant differences were found in the different species between lansoprazole and omeprazole as for the duration of action. 6. In conclusion, lansoprazole exerts a marked antisecretory effect in a variety of gastric secretion models from different species. However, it did not significantly differ from omeprazole when considering either the potency or the duration of action.

Lansoprazole versus ranitidine for the treatment of reflux oesophagitis. UK Lansoprazole Clinical Research Group

BACKGROUND

Lansoprazole is a H+.K(+)-ATPase (proton pump) inhibitor with an anti-secretory action and is therefore potentially useful in the treatment of gastro-oesophageal reflux.

METHODS

This study was conducted to determine the efficacy and short-term safety of lansoprazole at doses of 30 mg or 60 mg once daily, compared with ranitidine 150 mg twice daily, in the treatment of patients with reflux oesophagitis. This was a double-blind, stratified, randomized, comparative, parallel group study conducted in five centres in the UK. A total of 229 patients (155 men) aged 18-79 years with endoscopically-confirmed oesophagitis were randomized to receive lansoprazole 30 mg p.o. daily, lansoprazole 60 mg p.o. daily, or ranitidine 150 mg p.o. b.d. Efficacy was assessed by endoscopic examination at 4 weeks and 8 weeks, together with symptom relief and antacid usage.

RESULTS

Lansoprazole 30 mg and 60 mg were superior at 4 and 8 weeks (P < 0.01) to ranitidine in healing reflux oesophagitis: respective healing rates being 84%, 72% and 39% after 4 weeks and 92%, 91% and 53% after 8 weeks. Relief of heartburn with lansoprazole 30 mg and 60 mg was superior to that achieved with ranitidine at both week 4 (P < 0.01) and week 8 (P < 0.02). Sixty-four patients experienced a total of 85 adverse events, one-third of which were considered drug-related. The incidence and severity were similar in the three groups.

CONCLUSION

Lansoprazole 30 mg and 60 mg once daily are more effective than ranitidine 150 mg twice daily in the short-term treatment of reflux oesophagitis.