Nocturnal gastric acidity and acid breakthrough on different regimens of omeprazole 40 mg daily

Proton Pump Inhibitors Do Not Affect the Bioavailability of a Novel Liquid Formulation of Levothyroxine

OBJECTIVE

This study evaluates the impact of a representative proton pump inhibitor (PPI) (omeprazole), administered simultaneously or staggered, on the pharmacokinetics of levothyroxine (LT4) solution (Tirosint-SOL).

METHODS

This was a randomized, 3-way crossover, comparative bioavailability study in 36 healthy adults under fasting conditions. Omeprazole 40 mg delayed-release capsule was administered once daily from Day 1 to 6 (mornings, Treatment-A; evenings, Treatment-B; none, Treatment-C) to increase and stabilize gastric pH. In the morning of Day 5, a single dose of LT4 solution 600 mcg was administered. Blood samples were collected 0 to 48 hours post-LT4 administration. Noncompartmental pharmacokinetic parameters were calculated for total serum thyroxine using baseline-corrected data. Maximum concentration (Cmax) and area under the concentration-time curve (AUC0-48) were included in an analysis of variance to obtain geometric mean ratios and 90% confidence intervals.

RESULTS

For both comparisons (A/C and B/C), geometric mean ratios and 90% confidence intervals for all parameters were within the equivalence boundaries (80%-125%), indicating bioequivalence: for A/C, AUC0-48 98.98% [94%-104%], and Cmax 91.68% [87%-97%]; for B/C, AUC0-48 98.94% [95%-103%], and Cmax 94.90% [90%-100%]. Median Tmax (time associated with Cmax) was similar across treatments.

CONCLUSION

This study demonstrated that Tirosint-SOL bioavailability is unaffected by coadministration of a representative PPI, given simultaneously or staggered by about 12 hours, compared to administration of LT4 solution alone. For hypothyroid patients on PPI therapy, administration of LT4 solution may reduce variations in thyroid stimulating hormone levels related to intermittent use of acid-reducing drugs and consequently the need for dose adjustments.

Twice-Daily Proton Pump Inhibitor Induces Higher Remission Rate in Eosinophilic Esophagitis Than Once-Daily Regimen Regardless of Total Daily Dose

INTRODUCTION

The optimal proton pump inhibitor (PPI) regimen for eosinophilic esophagitis (EoE) is unclear. We compared histologic response rates of different dosing combinations.

METHODS

A total of 305 patients with newly diagnosed EoE received standard (omeprazole 20 mg daily), once-daily moderate (40 mg daily), twice-daily moderate (20 mg twice daily), or high (40 mg twice daily) dose PPI for ≥8 weeks.

RESULTS

Approximately 42.3% achieved histologic response to PPI, with higher rates for twice-daily (moderate 52.8%/high 54.3%) than once-daily (standard 11.8%/moderate 10%) dosing ( P < 0.0001). On multivariable analysis, twice-daily moderate (adjusted odds ratio 6.75, confidence interval 2.53-18.0, P = 0.0008) and high (adjusted odds ratio 12.8, confidence interval 4.69-34.8, P < 0.0001) doses independently predicted histologic response.

DISCUSSION

Twice-daily PPI is associated with higher EoE histologic response rates than once-daily regimen.

Nocturnal acid breakthrough and esophageal acidification during treatment with dexlansoprazole as compared to omeprazole in patients with gastroesophageal reflux disease

BACKGROUND

Nocturnal acid breakthrough (NAB) may differ based on duration of proton pump inhibitor (PPI) action and Helicobacter pylori (H. pylori) infection; NAB may influence esophageal acidification (EA) and mucosal damage. Dexlansoprazole, a long-acting PPI, was not compared with omeprazole for NAB, gastric acid suppression, and EA in relation to H. pylori infection.

METHODS

In this prospective open-label comparative observational study, gastroesophageal reflux disease (GERD) patients were evaluated using 24-h dual-channel pH-impedance monitoring while on dexlansoprazole (60 mg, n = 39) and omeprazole (20 mg, n = 41) to study the degree of gastric acid suppression, esophageal acid exposure, and NAB (primary outcome measures). H. pylori was detected by rapid urease test and histology.

RESULTS

NAB tended to be frequent with omeprazole than dexlansoprazole (33/41 [80.5%] vs. 23/39 [59%]; p = 0.06). Though nocturnal mean esophageal pH was comparable between the dexlansoprazole and omeprazole groups, its duration was less with the former (181.5 [15.2-334.2] vs. 283 [158-366] min, p = 0.03). NAB was as frequent in the H. pylori-infected than the non-infected group (11/19 [57.9%] vs. 45/61 [73.8%]; p = 0.1). The nocturnal gastric and esophageal pH in the H. pylori-infected group was higher than in the non-infected group (4.6 ± 1.7 vs. 4 ± 1.6, p = 0.157; 6.1 ± 0.6 vs. 5.8 ± 0.6, p = 0.128). Dexlansoprazole tended to increase 24-h and nocturnal mean gastric pH among H. pylori-infected more than omeprazole (5.9 ± 1.1 vs. 4.2 ± 1.7, p = 0.023; 5.7 ± 1.2 vs. 3.8 ± 1.5, p = 0.006).

CONCLUSION

Dexlansoprazole is more effective than omeprazole in suppressing gastric acid secretion, resulting in lesser EA and NAB, particularly in the presence of H. pylori.

ACG Clinical Guideline for the Diagnosis and Management of Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD) continues to be among the most common diseases seen by gastroenterologists, surgeons, and primary care physicians. Our understanding of the varied presentations of GERD, enhancements in diagnostic testing, and approach to patient management have evolved. During this time, scrutiny of proton pump inhibitors (PPIs) has increased considerably. Although PPIs remain the medical treatment of choice for GERD, multiple publications have raised questions about adverse events, raising doubts about the safety of long-term use and increasing concern about overprescribing of PPIs. New data regarding the potential for surgical and endoscopic interventions have emerged. In this new document, we provide updated, evidence-based recommendations and practical guidance for the evaluation and management of GERD, including pharmacologic, lifestyle, surgical, and endoscopic management. The Grading of Recommendations, Assessment, Development, and Evaluation system was used to evaluate the evidence and the strength of recommendations. Key concepts and suggestions that as of this writing do not have sufficient evidence to grade are also provided.

Refractory Gastroesophageal Reflux Disease: A Management Update

Gastroesophageal reflux disease (GERD) is one of the most frequent gastrointestinal disorders. Proton pump inhibitors (PPIs) are effective in healing lesions and improving symptoms in most cases, although up to 40% of GERD patients do not respond adequately to PPI therapy. Refractory GERD (rGERD) is one of the most challenging problems, given its impact on the quality of life and consumption of health care resources. The definition of rGERD is a controversial topic as it has not been unequivocally established. Indeed, some patients unresponsive to PPIs who experience symptoms potentially related to GERD may not have GERD; in this case the definition could be replaced with “reflux-like PPI-refractory symptoms.” Patients with persistent reflux-like symptoms should undergo a diagnostic workup aimed at finding objective evidence of GERD through endoscopic and pH-impedance investigations. The management strategies regarding rGERD, apart from a careful check of patient's compliance with PPIs, a possible change in the timing of their administration and the choice of a PPI with a different metabolic pathway, include other pharmacologic treatments. These include histamine-2 receptor antagonists (H2RAs), alginates, antacids and mucosal protective agents, potassium competitive acid blockers (PCABs), prokinetics, gamma aminobutyric acid-B (GABA-B) receptor agonists and metabotropic glutamate receptor-5 (mGluR5) antagonists, and pain modulators. If there is no benefit from medical therapy, but there is objective evidence of GERD, invasive antireflux options should be evaluated after having carefully explained the risks and benefits to the patient. The most widely performed invasive antireflux option remains laparoscopic antireflux surgery (LARS), even if other, less invasive, interventions have been suggested in the last few decades, including endoscopic transoral incisionless fundoplication (TIF), magnetic sphincter augmentation (LINX) or radiofrequency therapy (Stretta). Due to the different mechanisms underlying rGERD, the most effective strategy can vary, and it should be tailored to each patient. The aim of this paper is to review the different management options available to successfully deal with rGERD.

Effect of Food and Dosing Regimen on Safety and Efficacy of Proton Pump Inhibitors Therapy-A Literature Review

Proton pump inhibitors (PPIs) are the first-choice drugs used to prevent and treat acid-related diseases. However, a lack of satisfactory response to the standard PPI dose ("PPI failure") is often reported, especially in patients with gastroesophageal reflux disease. Poor compliance seems to be one of the main causes of PPI failure; hence, it is crucial to gain knowledge on how to properly administer PPIs. In this review, we aimed to evaluate the effect of food, beverages, and dosing regimen on pharmacokinetics and pharmacodynamics of PPIs and to frame recommendations for healthcare professionals to improve both patient's counseling and compliance to treatment with PPIs. A total of 201 papers were identified following a literature search. After full-text evaluation, 64 studies were included in the review. Co-administration of PPIs with a meal may affect both their bioavailability and effectiveness; however, the influence of food depends on the type of drug and its formulation. Except for pantoprazole, PPIs can be administered in the morning or evening; however, morning intake generally provides better daytime control of gastric acidity. In most cases, the choice of the proper schedule of administration should be based on the patient's symptoms and individual dosing preferences.

Rethinking gastroesophageal reflux disorder

Gastroesophageal reflux disease (GERD) is a common clinical condition for which our understanding has evolved over the past decades. It is now considered a cluster of phenotypes with numerous anatomical and physiological abnormalities contributing to its pathophysiology. As such, it is important to first understand the underlying mechanism of the disease process for each patient before embarking on therapeutic interventions. The aim of our paper is to highlight the mechanisms contributing to GERD and review investigations and interpretation of these results. Finally, the paper reviews the available treatment modalities for this condition, ranging from medical intervention, endoscopic options through to surgery and its various techniques.

Clinical consequences of controversies in gastric physiology

Studies on the regulation of gastric acid secretion started more than 100 years ago at an early phase of experimental physiology. In nearly the whole last century there were disputes about the interpretation of the findings: the interaction between the three principle gastric acid secretagogues acetylcholine, gastrin and histamine, the cell producing the relevant histamine which turned out to be the ECL cell, the ability of the ECL cell to divide and thus develop into tumours, the classification of gastric carcinomas and the mechanism for Helicobacter pylori carcinogenesis. The elucidation of the central role of the ECL cell and thus its main regulator, gastrin, solve all these controversies, and gives a solid base for handling upper gastrointestinal diseases.

Proton Pump Inhibitors: The Good, Bad, and Ugly

Proton pump inhibitors (PPIs) continue to be the medication of choice for treatment of acid-related disease, with few if any overt side effects seen with daily use. They are often prescribed empirically, often in high doses and with many patients being treated with multiple PPIs without an objective diagnosis. Therefore, they are believed to be overprescribed and used without indication. In this article we discuss the appropriate clinical indications for PPIs, review in detail the major associated adverse events, and put in perspective key issues in balancing benefits and risk of this exceptional (and safe) class of drug.

Impact of head of bed elevation in symptoms of patients with gastroesophageal reflux disease: a randomized single-blind study (IBELGA)

BACKGROUND

The clinical impact of head-of-bed elevation in patients with gastro-oesophageal reflux disease is unclear, because of inconsistency and methodological limitations of previous studies.

PATIENTS AND METHODS

A randomised single-blind single-centre controlled clinical trial with a 2x2 cross-over design, in 39 pharmacologically treated patients with gastro-oesophageal reflux disease. Active intervention was to use a head-of-bed-elevation of 20cm for 6 weeks and then to sleep without inclination for 6 additional weeks, with a wash-out of 2 weeks between periods. The primary outcome was a change ≥10% in RDQ score and secondary outcomes were a change ≥10% in SF-36 score, patient preference and frequency of adverse events.

RESULTS

27 (69.2%) patients who used the intervention reached the primary outcome vs 13 (33.3%) patients in the control group (RR: 2.08; 95 CI%: 1.19 - 3.61). No effect was found in SF-36 score (RR: 1.11; 95% CI: 0.47 - 2.60). Preference favouring the intervention was 77.1% and adverse event proportion was 54.0%.

CONCLUSION

Head-of-bed elevation improved reflux symptoms but there was no effect on quality of life. The finding of a non-optimal risk-benefit ratio warrants additional studies before this intervention can be recommended (IBELGA, ClinicalTrials.gov identifier NCT02706938).

Practical considerations in the management of proton-pump inhibitors

Proton-pump inhibitors (PPIs) are one of the most active ingredients prescribed in Spain. In recent decades there has been an overuse of these drugs in both outpatient clinics and hospitals that has lead to a significant increase in healthcare spending and to an increase in the risk of possible side effects. It is important for health professionals to know the accepted indications and the correct doses for the use of these drugs. On the market there are different types of PPI: omeprazole, pantoprazole, lansoprazole, rabeprazole and esomeprazole. Omeprazole is the oldest and most used PPI, being also the cheapest. Although there are no important differences between PPIs in curing diseases, esomeprazole, a new-generation PPI, has proved to be more effective in eradicating H. pylori and in healing severe esophagitis compared to other PPIs. In recent years the use of generic drugs has spread; these drugs have the same bioavailability than the original drugs. In the case of PPIs, the few comparative studies available in the literature between original and generic drugs have shown no significant differences in clinical efficacy.

Diagnosis and treatment of gastroesophageal reflux disease: recommendations of the Asociación Mexicana de Gastroenterología

Emerging concepts in the pathophysiology of gastroesophageal reflux disease (GERD) and the constant technologic advances in the diagnosis and treatment of this clinical condition make it necessary to frequently review and update the clinical guidelines, recommendations, and official statements from the leading academic groups worldwide. The Asociación Mexicana de Gastroenterología (AMG), aware of this responsibility, brought together national experts in this field to analyze the most recent scientific evidence and formulate a series of practical recommendations to guide and facilitate the diagnostic process and efficacious treatment of these patients. The document includes algorithms, figures, and tables for convenient consultation, along with opinions on GERD management in sensitive populations, such as pregnant women and older adults.

Gastroesophageal Acid Reflux Control 5 Years After Antireflux Surgery, Compared With Long-term Esomeprazole Therapy

BACKGROUND & AIMS

We compared the ability of laparoscopic antireflux surgery (LARS) and esomeprazole to control esophageal acid exposure, over a 5-year period, in patients with chronic gastroesophageal reflux disease (GERD). We also studied whether intraesophageal and intragastric pH parameters off and on therapy were associated with long-term outcomes.

METHODS

We analyzed data from a prospective, randomized, open-label trial comparing the efficacy and safety of LARS vs esomeprazole (20 or 40 mg/d) over 5 years in patients with chronic GERD. Ambulatory intraesophageal and intragastric 24-hour pH monitoring data were compared between groups before LARS or the start of esomeprazole treatment, and 6 months and 5 years afterward. A secondary aim was to evaluate the association between baseline and 6-month pH parameters and esomeprazole dose escalation, reappearance of GERD symptoms, and treatment failure over 5 years in patients receiving LARS or esomeprazole.

RESULTS

In the LARS group (n = 116), the median 24-hour esophageal acid exposure was 8.6% at baseline and 0.7% after 6 months and 5 years (P < .001 vs baseline). In the esomeprazole group (n = 151), the median 24-hour esophageal acid exposure was 8.8% at baseline, 2.1% after 6 months, and 1.9% after 5 years (P < .001, therapy vs baseline, and LARS vs esomeprazole). Gastric acidity was stable in both groups. Patients who required a dose increase to 40 mg/d had more severe supine reflux at baseline, and decreased esophageal acid exposure (P < .02) and gastric acidity after dose escalation. Esophageal and intragastric pH parameters, off and on therapy, did not predict long-term symptom breakthrough.

CONCLUSIONS

In a prospective study of patients with chronic GERD, esophageal acid reflux was reduced greatly by LARS or esomeprazole therapy. However, patients receiving LARS had significantly greater reductions in 24-hour esophageal acid exposure after 6 months and 5 years. Esophageal and gastric pH, off and on therapy, did not predict long-term outcomes of patients. Abnormal supine acid exposure predicted esomeprazole dose escalation. ClinicalTrials.Gov identifier: NCT00251927 (available: http://clinicaltrials.gov/ct2/show/NCT00251927).

Potent Gastric Acid Inhibition Over 24 Hours by 4-Times Daily Dosing of Esomeprazole 20 mg

BACKGROUND

When administered at a standard dose, proton pump inhibitors (PPIs) do not always provide sufficient acid inhibition for all subjects, particularly in extensive metabolizers (EMs) of CYP2C19. Whether esomeprazole at a dose of 20 mg four times daily dosing (q.i.d.) can attain sufficient acid inhibition throughout 24 h in EMs remains unclear. We therefore investigated the efficacy of esomeprazole q.i.d. for acid inhibition.

METHODS

In a randomized cross-over design, 30 Helicobacter pylori-negative healthy young Japanese volunteers received esomeprazole at a dose of 20 mg two times a day (b.i.d.) or q.i.d. for 7 days. A pH monitoring was conducted before the trial as a control and on day 7 of both regimens.

RESULTS

Median pH values in the q.i.d. regimen were significantly higher than those with the b.i.d. regimen in EMs (b.i.d.: 5.3, q.i.d.: 6.6, p = 0.022), intermediate metabolizer (IM) (b.i.d.: 5.5, q.i.d.: 6.8, p = 0.005) and poor metabolizer (PM) (b.i.d.: 6.2, q.i.d.: 7.0, p = 0.047), respectively. Median pH with the b.i.d. regimen differed significantly by CYP2C19 genotypes (p = 0.004), but not the q.i.d. regimen (p = 0.384).

CONCLUSION

Esomeprazole q.i.d. achieved potent acid inhibition in all Helicobacter pylori-negative subjects, irrespective of CYP2C19 genotype, which might be one of the rescue regimens for patients' refractory to PPI treatment.

Refractory gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a condition that develops when the reflux of stomach contents into the esophagus causes troublesome symptoms, esophageal injury, and/or complications. Use of proton pump inhibitors (PPI) remains the standard therapy for GERD and is effective in most patients. Those whose symptoms are refractory to PPIs should be evaluated further and other treatment options should be considered, according to individual patient characteristics. Response to PPIs could be total (no symptoms), partial (residual breakthrough symptoms), or absent (no change in symptoms). Patients experiencing complete response do not usually need further management. Patients with partial response can be treated surgically or by using emerging endoscopic therapies. Patients who exhibit no response to PPI need further evaluation to rule out other causes.

Diagnosis and treatment of gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a common disease with a prevalence as high as 10%-20% in the western world. The disease can manifest in various symptoms which can be grouped into typical, atypical and extra-esophageal symptoms. Those with the highest specificity for GERD are acid regurgitation and heartburn. In the absence of alarm symptoms, these symptoms can allow one to make a presumptive diagnosis and initiate empiric therapy. In certain situations, further diagnostic testing is needed to confirm the diagnosis as well as to assess for complications or alternate causes for the symptoms. GERD complications include erosive esophagitis, peptic stricture, Barrett’s esophagus, esophageal adenocarcinoma and pulmonary disease. Management of GERD may involve lifestyle modification, medical therapy and surgical therapy. Lifestyle modifications including weight loss and/or head of bed elevation have been shown to improve esophageal pH and/or GERD symptoms. Medical therapy involves acid suppression which can be achieved with antacids, histamine-receptor antagonists or proton-pump inhibitors. Whereas most patients can be effectively managed with medical therapy, others may go on to require anti-reflux surgery after undergoing a proper pre-operative evaluation. The purpose of this review is to discuss the current approach to the diagnosis and treatment of gastroesophageal reflux disease.

Pharmacokinetic evaluation of esomeprazole for the treatment of gastroesophageal reflux disease

INTRODUCTION

Proton pump inhibitors (PPIs) are widely used for the treatment of acid-related diseases such as gastroesophageal reflux disease (GERD). They are recommended by the American College of Gastroenterology for healing erosive esophagitis (EO) and as long-term treatment in patients with healed EO. The available PPIs differ somewhat in their pharmacokinetics and clinical properties, but whether these differences are of clinical relevance is a matter of debate. Some safety concerns have been raised with the use of PPIs, mostly an increased incidence of infectious diseases such as community-acquired pneumonia or Clostridium difficile diarrhea.

AREAS COVERED

This article explores the results of clinical studies on the pharmacokinetics and pharmacodynamics of esomeprazole , as well as on its clinical efficacy to manage patients with GERD.

EXPERT OPINION

GERD is a public health concern as its worldwide incidence and associated complications are increasing alongside the exponentially increasing problem of obesity. PPIs are the first pharmacological option because of their efficacy and overall positive risk-to-benefit ratio. Improved efficacy with the use of stereospecific isomers of PPIs, such as esomeprazole, has not yet been convincingly demonstrated. Nevertheless, because of individual experience with former treatment, some patients may report better symptom control when treated with a specific PPI rather than with others.

Comparison of acid inhibition with standard dosages of proton pump inhibitors in relation to CYP2C19 genotype in Japanese

INTRODUCTION

The aim of therapeutic regimens using proton pump inhibitors (PPIs) in patients with acid-related diseases is to potently inhibit acid secretion for the full 24 h. However, optimum treatment is still unclear because the pharmacodynamics of PPIs differ among CYP2C19 genotypes and most of the previous studies have had loss of sample power.

METHODS

Using pH monitoring, we compared acid inhibition at standard dosage of omeprazole (20 mg, 50 times), lansoprazole (30 mg, 68 times), and rabeprazole (10 mg, 65 times) in Helicobacter pylori-negative healthy young Japanese volunteers.

RESULTS

Median pH with rabeprazole was 5.4 (3.3-7.5), which was significantly greater than with either omeprazole [4.4 (2.1-7.3)] or lansoprazole [4.8 (3.5-6.4)] (both P < 0.05). Median 24-h pH differed among the different CYP2C19 genotypes in all three PPIs. In CYP2C19 extensive metabolizers (EMs), the genotype that is refractory to PPI treatment, median pH with omeprazole, lansoprazole, and rabeprazole was 3.8 (2.1-4.4), 4.5 (3.5-5.3) and 4.8 (3.3-7.5), respectively.

DISCUSSION

Treatment with the selected PPIs at their standard dosages had difficulty maintaining acid inhibition for a full 24 h, especially in CYP2C19 EM. However, rabeprazole has the merit of less influence of CYP2C19 genotype compared with the other PPIs.

Acid peptic diseases: pharmacological approach to treatment

Acid peptic disorders are the result of distinctive, but overlapping pathogenic mechanisms leading to either excessive acid secretion or diminished mucosal defense. They are common entities present in daily clinical practice that, owing to their chronicity, represent a significant cost to healthcare. Key elements in the success of controlling these entities have been the development of potent and safe drugs based on physiological targets. The histamine-2 receptor antagonists revolutionized the treatment of acid peptic disorders owing to their safety and efficacy profile. The proton-pump inhibitors (PPIs) represent a further therapeutic advance due to more potent inhibition of acid secretion. Ample data from clinical trials and observational experience have confirmed the utility of these agents in the treatment of acid peptic diseases, with differential efficacy and safety characteristics between and within drug classes. Paradigms in their speed and duration of action have underscored the need for new chemical entities that, from a single dose, would provide reliable duration of acid control, particularly at night. Moreover, PPIs reduce, but do not eliminate, the risk of ulcers in patients taking NSAIDs, reflecting untargeted physiopathologic pathways and a breach in the ability to sustain an intragastric pH of more than 4. This review provides an assessment of the current understanding of the physiology of acid production, a discussion of medications targeting gastric acid production and a review of efficacy in specific acid peptic diseases, as well as current challenges and future directions in the treatment of acid-mediated diseases.

New and future drug development for gastroesophageal reflux disease

Medical therapy remains the most popular treatment for gastroesophageal reflux disease (GERD). Whilst interest in drug development for GERD has declined over the last few years primarily due to the conversion of most proton pump inhibitor (PPI)'s to generic and over the counter compounds, there are still numerous areas of unmet needs in GERD. Drug development has been focused on potent histamine type 2 receptor antagonist's, extended release PPI's, PPI combination, potassium-competitive acid blockers, transient lower esophageal sphincter relaxation reducers, prokinetics, mucosal protectants and esophageal pain modulators. It is likely that the aforementioned compounds will be niched for specific areas of unmet need in GERD, rather than compete with the presently available anti-reflux therapies.

Effects of Esomeprazole on the Pharmacokinetics of Lapatinib in Breast Cancer Patients

The aqueous solubility of lapatinib declines significantly at pH >4, suggesting that its bioavailability might be lowered by acid-reducing drugs. A study was therefore conducted to assess the effects of esomeprazole on lapatinib pharmacokinetics (PK). Women with metastatic human epidermal growth factor receptor 2 positive (HER2(+) ) breast cancer were enrolled. Patients received 1,250 mg lapatinib once daily (QD) in the morning on Days 1-7 (Period 1) and Days 8-14 (Period 2) with 40 mg esomeprazole QD at bedtime 3 hours after dinner on Days 8-14. Lapatinib PK sampling occurred during the 24-hour steady-state dosing intervals on Day 7 (lapatinib alone) and Day 14 (lapatinib with esomeprazole). Esomeprazole treatment resulted in decreased lapatinib bioavailability (mean 26%, range 6-49%) that was inversely associated with patient age as a significant covariate.

Proton pump inhibitors: the good, the bad, and the unwanted

Proton pump inhibitors (PPIs) are one of the most commonly prescribed classes of medications in the United States. By inhibiting gastric H/K adenosine triphosphatase via covalent binding to the cysteine residues of the proton pump, they provide the most potent acid suppression available. Long-term PPI use accounts for the majority of total PPI use. Absolute indications include peptic ulcer disease, chronic nonsteroidal anti-inflammatory drugs use, treatment of Helicobacter pylori, and erosive esophagitis. Although PPIs are generally considered safe, numerous adverse effects, particularly associated with long-term use have been reported. Many patients receiving chronic PPI therapy do not have clear indications for their use, prompting consideration for reduction or discontinuation of their use. This article reviews the indications for PPI use, the adverse effects/risks involved with their use, and conditions in which their use is controversial.

Step-by-step management of refractory gastresophageal reflux disease

Up to a third of the patients who receive proton pump inhibitor (PPI) once daily will demonstrate lack or partial response to treatment. There are various mechanisms that contribute to PPI failure and they include residual acid reflux, weakly acidic and weakly alkaline reflux, esophageal hypersensitivity, and psychological comorbidity, among others. Some of these underlying mechanisms may coincide in the same patient. Evaluation for proper compliance and adequate dosing time of PPIs should be the first management step before ordering invasive diagnostic tests. Doubling the PPI dose or switching to another PPI is the second step of management. Upper endoscopy and pH testing appear to have limited diagnostic value in patients who failed PPI treatment. In contrast, esophageal impedance with pH testing (multichannel intraluminal impedance MII-pH) on therapy appears to provide the most insightful information about the subsequent management of these patients (step 3). In step 4, treatment should be tailored to the specific underlying mechanism of patient's PPI failure. For those who demonstrate weakly acidic or weakly alkaline reflux as the underlying cause of their residual symptoms, transient lower esophageal sphincter relaxation reducers, endoscopic treatment, antireflux surgery and pain modulators should be considered. In those with functional heartburn, pain modulators are the cornerstone of therapy.

Rabeprazole 10 mg q.d.s. decreases 24-h intragastric acidity significantly more than rabeprazole 20 mg b.d. or 40 mg o.m., overcoming CYP2C19 genotype

BACKGROUND

Standard dosing (i.e. once daily) of proton pump inhibitors (PPIs) cannot inhibit acid secretion for a full 24 h. Better therapeutic regimens using PPIs are required to sustain potent acid inhibition for the full 24 h in all patients with acid-related diseases.

AIM

To evaluate acid inhibitory effects by different dosing times of a PPI at the same daily dosage, in a study involving 70 rounds of pH monitoring.

METHODS

Using pH monitoring, we evaluated the efficacy of different divided treatment regimens with the same total daily dose of rabeprazole (40 mg o.m., 15 rounds; 20 mg b.d., 20 rounds; 10 mg q.d.s., 35 rounds) on day 7 or 8 of PPI dosing.

RESULTS

In the study of divided treatment, the median pH (when administered once, twice or four times to achieve a daily dose of 40 mg) was 4.8 (3.6-6.4), 5.7 (4.1-7.4), 6.6 (4.9-8.4), respectively. When comparing the median pHs at the same CYP2C19 genotype among different dosing times of rabeprazole, the median pH attained with 10 mg q.d.s. was significantly higher than that in 40 mg o.m. or 20 mg b.d. Increase in the frequency of dosing effectively increased pH [median percent time of pH > 4.0 with q.d.s. therapy: 95.5% (63.2-100.0%)], irrespective to CYP2C19 genotype.

CONCLUSION

Four times daily dosing with rabeprazole 10 mg achieved potent acid inhibition, including during the night-time, suggesting its potential usefulness as a regimen for patients who are refractory to standard once daily PPI treatment.

Gastroesophageal reflux disease and sleep disturbances

Nighttime reflux during sleep plays a crucial role in several conditions associated with gastroesophageal reflux disease (GERD). Reflux patterns during arousal and sleep are different because of delayed gastric emptying, reduced esophageal peristalsis, decreases in swallowing and salivary secretion, and prolonged esophageal clearance during sleep. Clinical evidence strongly suggests that GERD is associated with sleep disturbances such as shorter sleep duration, difficulty falling asleep, arousals during sleep, poor sleep quality, and awakening early in the morning. New mechanisms on how GERD affects sleep have been recently identified by using actigraphy, and sleep deprivation was found to induce esophageal hyperalgesia to acid perfusion. Thus, the relationship between GERD and sleep disturbances is bidirectional. Among lifestyle modifications, avoidance of a late night meal plays a role in prevention of nighttime reflux. Treatment with a proton pump inhibitor (PPI) improves both nighttime symptoms and subjective sleep parameters, but its effects on objective sleep parameters remain unclear. Better control of nighttime acid secretion by administering a PPI at different times or by providing a double-dose PPI, adding H(2) receptor antagonists, or other new agents is proposed. The effects of such treatments on sleep disturbances remain to be elucidated. GERD patients with sleep disturbances report more severe symptoms and poorer quality of life as compared to those without sleep disturbances. Consequently, GERD should also be classified as GERD with sleep disturbance and GERD without sleep disturbance.

Therapeutic options for refractory gastroesophageal reflux disease

Refractory gastroesophageal reflux disease may affect up to one-third of the patients that consume proton pump inhibitor (PPI) once daily. Treatment in clinical practice has been primarily focused on doubling the PPI dose, despite lack of evidence of its value. In patients who failed PPI twice daily, medical treatment has been primarily focused on reducing transient lower esophageal sphincter relaxation rate or attenuating esophageal pain perception using visceral analgesics. In patients with evidence of reflux as the direct trigger of their symptoms, endoscopic treatment or antireflux surgery may be helpful in remitting symptoms. The role of psychological interventions, as well as non-traditional therapeutic strategies remains to be further elucidated.

Relative bioavailability of a 5 mg mosapride/10 mg rabeprazole fixed dose combination tablet versus separate single tablets in healthy volunteers: a single-dose randomized open-label crossover study

OBJECTIVE

To evaluate the relative bioavailability of a new formulation containing 5 mg mosapride and 10 mg rabeprazole (T) and compare it with the branded formulations of both drugs co-administered in separate tablets (R) to meet the regulatory requirements of bioequivalence in Argentina.

METHODS

A randomized-sequence, open-label, two-period crossover study was conducted on 24 healthy Caucasian volunteers in a fasting state. A single oral dose of either T or R formulations was followed by a 7-day washout period. Blood samples for mosapride were collected before administration (baseline) and at 0.5, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 12, 18, and 24 h after administration. Samples for rabeprazole were taken baseline and at 1, 2, 2.5, 3, 3.5, 4, 4.5, 5, 6, 7, 8 and 10 h after dosing. Mosapride and rabeprazole concentrations were determined using a validated LC-MS/MS method. Adverse events were monitored based on clinical parameters and volunteer reports.

RESULTS

The geometric means (90% CI) C(max) for mosapride in T and R were 23.13 (20.05-39.45) and 23.09 (21.69-32.37) ng/mL, the AUC(0-)(t) were 70.80 (66.23-102.37) and 70.81 (66.35-93.26) ng h/mL and the AUC(0-∞) were 74.05 (69.29-106.11) and 74.98 (70.43-97.77) ng h/mL. For rabeprazole T and R the C(max) were 197.42 (186.12-239.91) and 195.50 (186.08-250.07) ng/mL, the AUC(0-)(t) were 294.90 (275.13-374.15) and 296.96 (280.11-387.89) ng h/mL and the AUC(0-∞) were 301.12 (280.78-380.82) and 304.07 (286.60-394.21), respectively. No differences were detected between the formulations. The T/R ratios (90% CI) for C(max), AUC(0-)(t) and AUC(0-∞) were 100.17% (82.35-121.84), 99.99% (87.58-114.16) and 98.77% (87.02-112.11) for mosapride, and 100.99% (85.14-119.77), 99.31% (84.74-116.38) and 99.03% (85.07-115.28) for rabeprazole. No subject complained of adverse events.

CONCLUSIONS

In this single-dose study, the mosapride/rabeprazole tablets (test formulation) met the criterion for bioequivalence with the reference formulations. Study limitations include single-dose, open-label design, and a small sample of healthy volunteers.

Pharmacological management of GERD: where does it stand now?

Gastroesophageal reflux disease (GERD) is very common and advances in drug development over recent years have markedly improved GERD management. A wide range of medications are currently used in GERD treatment, including antacids, Gaviscon, sucralfate, histamine-2 receptor antagonists and prokinetics. However, proton pump inhibitors (PPIs) remain the mainstay of treatment for GERD owing to their profound and consistent inhibitory effect on acid secretion. Despite the presence of a wide armamentarium of therapeutic modalities for GERD, many areas of unmet needs remain. Drug development has focused primarily on improving PPI efficacy, reducing the transient lower esophageal sphincter relaxation rate, attenuating esophageal sensitivity and developing esophageal mucosal protectants.

An algorithm for diagnosis and treatment of refractory GERD

Patients with gastro-esophageal reflux disease (GERD) who are not responding to proton pump inhibitors (PPIs) given once daily are very common. These therapy-resistant patients have become the new face of GERD in clinical practice in the last decade. Upper endoscopy appears to have a limited diagnostic value. In contrast, esophageal impedance with pH testing on therapy appears to provide the most insightful information about the subsequent management of these patients. Commonly, doubling the PPI dose or switching to another PPI will be offered to patients who failed PPI once daily. Failure of such therapeutic strategies is commonly followed by assessment for weakly or residual acidic reflux. There is growing information about the potential value of compounds that can reduce transient lower esophageal sphincter relaxation rate. Esophageal pain modulators are commonly offered to patients with functional heartburn although supportive clinical studies are still missing.

The effects of dose and timing of esomeprazole administration on 24-h, daytime and night-time acid inhibition in healthy volunteers

BACKGROUND

Symptoms of gastro-oesophageal reflux disease (GERD) may persist despite daily treatment with a proton pump inhibitor (PPI).

AIM

To compare the pharmacodynamic effect of various esomeprazole dosage and timing regimens in healthy volunteers.

METHODS

The effect of different esomeprazole dosage regimens [20 mg once daily (od) before breakfast or dinner; 20 mg twice daily (b.d.); 40 mg od before breakfast, dinner or at bedtime; and 40 mg b.d.] on 24-h, daytime and night-time acid inhibition was evaluated in a randomized, seven-way crossover study in healthy volunteers. Each regimen was taken for 5 days.

RESULTS

Over the 24-h period (day 5), esomeprazole 20 mg b.d. was associated with superior acid inhibition vs. all 20 mg and 40 mg od regimens (P < 0.05), but was less effective than esomeprazole 40 mg b.d. (P < 0.05). Dosing with esomeprazole 20 mg or 40 mg od before breakfast gave improved 24-h and daytime acid inhibition vs. the corresponding administration before dinner or at bedtime (all P < 0.05). Night-time acid inhibition was improved when esomeprazole 40 mg od was administered before dinner or at bedtime vs. before-breakfast dosing (P < 0.05).

CONCLUSION

Varying the dose and timing of esomeprazole administration may provide acid inhibition appropriate for the symptom pattern of individual patients with GERD.

Relationship between esomeprazole dose and timing to heartburn resolution in selected patients with gastroesophageal reflux disease

OBJECTIVE

To increase response rates to therapy by increasing the dosage of proton pump inhibitor (PPI) therapy in patients with gastroesophageal reflux disease (GERD) whose symptoms are predominantly associated with acid reflux.

METHODS

In this double-blind, randomized, proof-of-concept study, 369 patients with GERD and moderate heartburn lasting ≥three days/week, a history of response to antacids/acid suppression therapy, and a positive esophageal acid perfusion test result were randomized to esomeprazole 20 or 40 mg once daily, or to 40 mg twice daily for four weeks. Heartburn symptom relief/resolution was subsequently evaluated.

RESULTS

In this study population, no relationship was apparent between esomeprazole dosage and efficacy variables for sustained heartburn resolution (seven days without symptoms) at week 4 (48.0%, 44.0%, and 41.4% for esomeprazole 20 mg once daily, 40 mg once daily, and 40 mg twice daily, respectively). Nocturnal heartburn resolution with esomeprazole 40 mg twice daily showed a numeric improvement trend versus esomeprazole 20 and 40 mg once daily, but this was not statistically significant.

CONCLUSIONS

Heartburn resolution rates at four weeks were similar for all esomeprazole dosages and comparable with rates reported previously, suggesting a plateau effect in terms of clinical response to acid suppression with PPI therapy in this population of selected GERD patients.

Novel pyrimidines as acid pump antagonists (APAs)

A series of pyrimidine derivatives as acid pump antagonists (APAs) was synthesized and the inhibitory activities against H(+)/K(+) ATPase isolated from hog gastric mucosa were determined. After elaborating on substituents at C2 and C4 position of the pyrimidine scaffold, we have observed that the compound 7h is a potent APA with H(+)/K(+) ATPase, IC(50) = 52 nM.

Management of gastroesophageal reflux disease that does not respond well to proton pump inhibitors

PURPOSE OF REVIEW

Patients with gastroesophageal reflux disease (GERD) who are not responding to proton pump inhibitors (PPIs) given once daily are very common. These therapy-resistant patients have become the new face of GERD in clinical practice in the last decade and presently pose a significant therapeutic challenge to the practicing physician. We reviewed newly accumulated information about the management of PPI failure that has been published over the past 2 years.

RECENT FINDINGS

There are diverse mechanisms that contribute to the failure of PPI treatment in GERD patients and they are not limited to residual reflux. Some of the causes of PPI failure may coincide in the same patient. Upper endoscopy appears to have limited diagnostic value. In contrast, esophageal impedance with pH testing on therapy appears to provide the most insightful information about the subsequent management of these patients. Commonly, doubling the PPI dose or switching to another PPI will be offered to patients who failed PPI once daily. Failure of such therapeutic strategies is commonly followed by assessment for residual reflux. There is growing information about the potential value of compounds that can reduce transient lower esophageal sphincter relaxations. Esophageal pain modulators are commonly offered to patients with functional heartburn, although supportive clinical studies are still missing.

SUMMARY

Management of refractory GERD patients remains an important clinical challenge. Recent studies have cemented the value of impedance-pH testing in pursuing proper treatment. Presently, the most promising therapeutic development for this patient population is transient lower esophageal sphincter relaxation reducers.

Proton pump inhibitors in the management of GERD

INTRODUCTION

Management of gastroesophageal reflux disease (GERD) is based on the concept that gastric contents, principally acid and pepsin, are responsible for symptoms of reflux and esophageal injury. Pharmacologic treatment is based on the principle that controlling intragastric pH will affect esophageal healing and subsequently symptom relief.

RESULTS AND DISCUSSION

Control of pH can be accomplished with antisecretory agents, principally proton pump inhibitors (PPIs). The majority of patients respond to a single daily dose of a PPI; however, some will require higher doses, and a small percentage are "refractory" to twice daily dosing of these drugs. The success of these agents, and in fact the reasons for "failure," is elucidated by understanding the mechanism of action of PPIs and the effect of dose timing and meals on their efficacy.

CONCLUSION

Awareness of new concerns regarding potential side effects of PPIs when used long-term require careful thought as GERD is a chronic disease with most needing some form of medical treatment over time. This article reviews the pharmacologic properties of PPIs and the impact on the treatment of GERD.

The pharmacokinetic profile of fesoterodine 8 mg with daytime or nighttime dosing

PURPOSE

Diurnal variation can affect drug pharmacokinetics. Fesoterodine is a new antimuscarinic drug for the treatment of overactive bladder (OAB). We estimated the relative bioavailability of 5-hydroxymethyl tolterodine (5-HMT), the active metabolite of fesoterodine, following nighttime and daytime administration.

METHODS

In this randomized, open-label, two-period, two-treatment crossover, single-dose study, healthy subjects received daytime and nighttime oral dosing of fesoterodine 8-mg sustained-release tablets, separated by a minimum 60-h washout period. Blood samples for 5-HMT PK determination were collected before dosing and at specified intervals up to 48 h postdose. Safety was assessed by adverse event (AE) reports.

RESULTS

Fourteen subjects completed the study. Plasma concentration versus time profiles (AUC) of 5-HMT were similar for daytime and nighttime dosing. Mean AUC(infinity) 5-HMT values were 47.9 and 51.4 ng h/mL for nighttime and daytime dosing, respectively; the mean time to reach maximum concentration (C(max)) values were 3.9 and 5.0 ng/mL, respectively. Nighttime versus daytime AUC(infinity) and C(max) ratios of 5-HMT were 93 and 79%, respectively; 90% confidence intervals (CIs) indicated equivalence for AUC(infinity) but not for C(max). The median time to reach maximum concentration (T(max)) was 5.0 h for both dosing regimens, and the mean terminal elimination half-life (T((1/2))) was 5.9 and 5.7 h for nighttime and daytime dosing, respectively. Seven treatment-related AEs, most commonly headache, occurred in five subjects.

CONCLUSIONS

The AUC values for daytime and nighttime administration of fesoterodine were equivalent. The 21% reduction in the C(max) for nighttime dosing is unlikely to be clinically relevant. No safety issues were apparent. These results support both daytime and nighttime administration of fesoterodine for OAB treatment.

Insights into the future of gastric acid suppression

The development of effective acid-suppression therapy (particularly PPIs) has revolutionized the treatment of acid-related diseases. Despite the overall effectiveness of these agents, they have some shortcomings, including a delayed onset of action, incomplete acid suppression in the majority of patients, and the need for ingestion before a meal to achieve maximal efficacy. Attempts to overcome these issues have included the development of isomeric PPIs (such as esomeprazole), alterations in drug delivery (such as delayed-release dexlansoprazole), and combined therapy with nonenterically coated PPIs and antacids (such as 'naked' omeprazole combined with sodium biocarbonate). Other acid-suppression agents in development or in late-phase trials include potassium-competitive acid blockers, new histamine receptor 2 antagonists, and gastrin antagonists. Although these agents could potentially achieve complete gastric acid suppression, risks may be associated with this level of suppression, including enteric infections and malabsorption of nutrients such as vitamin B(12), iron and calcium. This Review provides an update on the status of acid-suppression therapy and discusses directions for future research.

The relationship between gastroesophageal reflux disease and sleep

Recent studies demonstrate a bidirectional relationship between gastroesophageal reflux disease (GERD) and sleep in which nighttime reflux leads to sleep deprivation and sleep deprivation can exacerbate GERD by enhancing perception of intraesophageal stimuli. Current treatment primarily focuses on reducing nighttime reflux, thus improving sleep quality. Future studies are needed to further explore the relationship between GERD and sleep and the potential of novel therapeutic options to interrupt the vicious cycle between them.

A systematic review of the definitions, prevalence, and response to treatment of nocturnal gastroesophageal reflux disease

BACKGROUND & AIMS

More than half of patients with chronic gastroesophageal reflux (GERD) report nocturnal symptoms. We performed systematic literature review to define nocturnal heartburn and to determine potential causality between nocturnal reflux and extraesophageal manifestations.

METHODS

We performed a search of literature published from 1974-2007. Each study was examined by 2 reviewers and rated on the basis of study type and outcome.

RESULTS

Screening of 445 trials identified 59 (13%) studies relevant for analysis. Twenty-two (5%) of the trials described potential changes in sleep parameters resulting from treatment of heartburn. In most studies, nocturnal reflux was defined as heartburn symptoms that impacted sleep quality and duration. On the basis of 5 large population studies, the mean +/- standard deviation prevalence of nocturnal heartburn was 54% +/- 22%. Consequences of nocturnal reflux included poor sleep quality, daytime fatigue, difficulty initiating sleep or arousals from sleep, and impaired work productivity. The strength of the association between the occurrence of nocturnal reflux and late evening meals was flawed as a result of the confounding effect of the evening meal content. There was no evidence supporting causality between nocturnal heartburn and asthma or obstructive sleep apnea. Subjective, but not objective, measures of sleep improved with antireflux therapy. Head of bed elevation, proton pump inhibitor therapy, H(2)-receptor antagonists, and Nissen fundoplication alleviated nocturnal heartburn and associated sleep disturbances.

CONCLUSIONS

Nocturnal GERD is common and is associated with adverse sleep parameters. It can be effectively managed with medical and surgical therapy.

Control of 24-hour intragastric acidity with morning dosing of immediate-release and delayed-release proton pump inhibitors in patients with GERD

GOALS

To compare the effects of immediate-release omeprazole and 2 different delayed-release proton pump inhibitors on 24-hour intragastric acidity in gastroesophageal reflux disease patients.

BACKGROUND

Because of its unique pharmacokinetic properties, immediate-release omeprazole does not need to be dosed before a meal to control intragastric acidity. Previous studies showed effectiveness of immediate-release omeprazole in controlling nocturnal intragastric acidity with bedtime dosing. This is the first study to compare the effects of prebreakfast dosing of immediate-release omeprazole and delayed-release lansoprazole and pantoprazole on 24-hour intragastric acidity.

AIM

To compare the effects of prebreakfast dosing of immediate-release omeprazole 40 mg capsules, lansoprazole 30 mg capsules, and pantoprazole 40 mg tablets on 24-hour intragastric acidity.

METHODS

Fifty-five patients with gastroesophageal reflux disease received 7 consecutive once-daily morning doses of each drug in this open-label, randomized, 3-period crossover study. On day 7, intragastric pH was recorded for 24 hours.

RESULTS

After 7 days, the percentage of time with intragastric pH >4 over 24 hours was 59.7% (14.3 hours) with immediate-release omeprazole, 48.8% (11.7 hours) with lansoprazole (P=0.005), and 41.8% (10.0 hours) with pantoprazole (P<0.001). Median intragastric pH was significantly higher with immediate-release omeprazole than with lansoprazole (P=0.003) or pantoprazole (P<0.001). All drugs were well tolerated.

CONCLUSIONS

When dosed in the morning, immediate-release omeprazole provided significantly better control of 24-hour intragastric acidity than lansoprazole and pantoprazole.