Drug interaction studies with dexlansoprazole modified release (TAK-390MR), a proton pump inhibitor with a dual delayed-release formulation: results of four randomized, double-blind, crossover, placebo-controlled, single-centre studies

The Clinician's Guide to Proton Pump Inhibitor Related Adverse Events

A substantial volume of literature exists linking proton pump inhibitor (PPI) use with a multitude of serious adverse events. There is uncertainty, however, over whether these associations are clinically important. Excessive concern about PPI-related adverse events may leave patients at risk of harm by leaving acid-related upper gastrointestinal disease untreated. Conversely, the risk of treatments may outweigh the benefits if any of the purported adverse events are directly caused by PPI use; this is of particular concern where indications for PPI use are not present. In this paper, we review the studies which have reported associations between adverse events and PPI use, discuss the proposed mechanisms of action, grade the confidence in whether these associations are truly causal, and provide advice regarding balancing the benefits of PPI use against their possible harms.

Proton-pump inhibitors: understanding the complications and risks

Proton-pump inhibitors (PPIs) are the most effective therapy for the full spectrum of gastric-acid-related diseases. However, in the past decade, a steadily increasing list of complications following long-term use of PPIs has been reported. Their potent acid-suppressive action induces several structural and functional changes within the gastric mucosa, including fundic gland polyps, enterochromaffin-like cell hyperplasia and hypergastrinaemia, which can be exaggerated in the presence of Helicobacter pylori infection. As discussed in this Review, most associations of PPIs with severe adverse events are not based on sufficient evidence because of confounding factors and a lack of plausible mechanisms. Thus, a causal relationship remains unproven in most associations, and further studies are needed. Awareness of PPI-associated risks should not lead to anxiety in patients but rather should induce the physician to consider the appropriate dosing and duration of PPI therapy, including long-term monitoring strategies in selected groups of patients because of their individual comorbidities and risk factors.

The expression, induction and pharmacological activity of CYP1A2 are post-transcriptionally regulated by microRNA hsa-miR-132-5p

Cytochrome P450 1A2 (CYP1A2) is one of the most abundant and important drug metabolizing enzymes in human liver. However, little is known about the post-transcriptional regulation of CYP1A2, especially the mechanisms involving microRNAs (miRNAs). This study applied a systematic approach to investigate the post-transcriptional regulation of CYP1A2 by miRNAs. Candidate miRNAs targeting the 3'-untranslated region (3'-UTR) of CYP1A2 were screened in silico, resulting in the selection of sixty-two potential miRNAs for further analysis. The levels of two miRNAs, hsa-miR-132-5p and hsa-miR-221-5p, were inversely correlated with the expression of CYP1A2 mRNA transcripts in normal human liver tissue samples represented in The Cancer Genome Atlas (TCGA) dataset. The interactions between these miRNAs and cognate CYP1A2 mRNA sequences were evaluated using luciferase reporter gene studies and electrophoretic mobility shift assays, by which a direct interaction was confirmed involving hsa-miR-132-5p and a cognate binding site present in the CYP1A2 3'-UTR. Experiments by which hsa-miR-132-5p or random miRNA controls were introduced into HepG2, Huh-7 and HepaRG hepatic cell lines showed that only hsa-miR-132-5p suppressed the endogenous and lansoprazole-induced expression of CYP1A2, at biological activity, protein production, and mRNA transcript levels. Furthermore, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), and lactate dehydrogenase (LDH) assays showed that hsa-miR-132-5p attenuates CYP1A2-mediated, lansoprazole-enhanced, flutamide-induced hepatic cell toxicity. Results from multilayer experiments demonstrate that hsa-miR-132-5p suppresses the expression of CYP1A2 and that this suppression is able to decrease the extent of an adverse drug-drug interaction involving lansoprazole and flutamide.

Proton pump inhibitors for the treatment of patients with erosive esophagitis and gastroesophageal reflux disease: current evidence and safety of dexlansoprazole

Gastroesophageal reflux disease is the most common upper gastroenterology disorder in the US. It is associated with a variety of complications and significantly impacts quality of life. Proton pump inhibitors are the most effective treatment. Dexlansoprazole modified release (MR) is a proton pump inhibitor that employs a novel release formulation that prolongs its absorption and allows for more flexibility in dosing. Dexlansoprazole MR can be dosed without regard to food intake or time of day, and once-daily dosing may replace twice-daily dosing of other agents. Dexlansoprazole MR is effective for healing and maintenance of erosive esophagitis, and for the treatment of nonerosive disease, including nocturnal gastroesophageal reflux disease. Dexlansoprazole MR is safe and well tolerated, and can improve quality of life.

Pharmacokinetic drug interaction profiles of proton pump inhibitors: an update

Proton pump inhibitors (PPIs) are used extensively for the treatment of gastric acid-related disorders, often over the long term, which raises the potential for clinically significant drug interactions in patients receiving concomitant medications. These drug–drug interactions have been previously reviewed. However, the current knowledge is likely to have advanced, so a thorough review of the literature published since 2006 was conducted. This identified new studies of drug interactions that are modulated by gastric pH. These studies showed the effect of a PPI-induced increase in intragastric pH on mycophenolate mofetil pharmacokinetics, which were characterised by a decrease in the maximum exposure and availability of mycophenolic acid, at least at early time points. Post-2006 data were also available outlining the altered pharmacokinetics of protease inhibitors with concomitant PPI exposure. New data for the more recently marketed dexlansoprazole suggest it has no impact on the pharmacokinetics of diazepam, phenytoin, theophylline and warfarin. The CYP2C19-mediated interaction that seems to exist between clopidogrel and omeprazole or esomeprazole has been shown to be clinically important in research published since the 2006 review; this effect is not seen as a class effect of PPIs. Finally, data suggest that coadministration of PPIs with methotrexate may affect methotrexate pharmacokinetics, although the mechanism of interaction is not well understood. As was shown in the previous review, individual PPIs differ in their propensities to interact with other drugs and the extent to which their interaction profiles have been defined. The interaction profiles of omeprazole and pantoprazole sodium (pantoprazole-Na) have been studied most extensively. Several studies have shown that omeprazole carries a considerable potential for drug interactions because of its high affinity for CYP2C19 and moderate affinity for CYP3A4. In contrast, pantoprazole-Na appears to have lower potential for interactions with other medications. Lansoprazole and rabeprazole also seem to have a weaker potential for interactions than omeprazole, although their interaction profiles, along with those of esomeprazole and dexlansoprazole, have been less extensively investigated. Only a few drug interactions involving PPIs are of clinical significance. Nonetheless, the potential for drug interactions should be considered when choosing a PPI to manage gastric acid-related disorders. This is particularly relevant for elderly patients taking multiple medications, or for those receiving a concomitant medication with a narrow therapeutic index.

Proton pump inhibitors

Proton pump inhibitors (PPIs) can bind to the proton pump and inhibit it to secrete hydrogen ions. Since currently used PPIs have a short plasma half-life and can interact with other drugs, there is still an urgent need to develop new and interesting PPIs that can overcome these problems. This review summarizes the latest progress in research of PPIs with regard to the mechanism of action, side effects, and interactions with other drugs and provides an update of the status of acid-suppression therapy.

Evaluation of six proton pump inhibitors as inhibitors of various human cytochromes P450: focus on cytochrome P450 2C19

Six proton pump inhibitors (PPIs), omeprazole, lansoprazole, esomeprazole, dexlansoprazole, pantoprazole, and rabeprazole, were shown to be weak inhibitors of cytochromes P450 (CYP3A4, -2B6, -2D6, -2C9, -2C8, and -1A2) in human liver microsomes. In most cases, IC₅₀ values were greater than 40 μM, except for dexlansoprazole and lansoprazole with CYP1A2 (IC₅₀ = ∼8 μM) and esomeprazole with CYP2C8 (IC₅₀ = 31 μM). With the exception of CYP2C19 inhibition by omeprazole and esomeprazole (IC₅₀ ratio, 2.5 to 5.9), there was no evidence for a marked time-dependent shift in IC₅₀ (IC₅₀ ratio, ≤ 2) after a 30-min preincubation with NADPH. In the absence of preincubation, lansoprazole (IC₅₀ = 0.73 μM) and esomeprazole (IC₅₀ = 3.7 μM) were the most potent CYP2C19 inhibitors, followed by dexlansoprazole and omeprazole (IC₅₀ = ∼7.0 μM). Rabeprazole and pantoprazole (IC₅₀ = ≥ 25 μM) were the weakest. A similar ranking was obtained with recombinant CYP2C19. Despite the IC₅₀ ranking, after consideration of plasma levels (static and dynamic), protein binding, and metabolism-dependent inhibition, it is concluded that omeprazole and esomeprazole are the most potent CYP2C19 inhibitors. This was confirmed after the incubation of the individual PPIs with human primary hepatocytes (in the presence of human serum) and by monitoring their impact on diazepam N-demethylase activity at a low concentration of diazepam (2 μM). Data described herein are consistent with reports that PPIs are mostly weak inhibitors of cytochromes P450 in vivo. However, two members of the PPI class (esomeprazole and omeprazole) are more likely to serve as clinically relevant inhibitors of CYP2C19.

Dexlansoprazole MR for the management of gastroesophageal reflux disease

Dexlansoprazole modified release (MR; Dexilant™), the R-enantiomer of lansoprazole, was approved in the USA in 2009 for the management of erosive esophagitis and nonerosive reflux disease. Dexlansoprazole MR has a unique dual delayed-release delivery system that was designed to address unmet needs that may accompany the use of single-release proton pump inhibitors (PPIs), specifically, their short plasma half-life and requirement for meal-associated dosing. The delivery technology of dexlansoprazole MR is designed to release the drug in two separate pH-dependent phases, the first in the proximal duodenum and the second in the more distal small intestine. This extends plasma concentration and pharmacodynamic effects of dexlansoprazole MR beyond those of single-release PPIs and allows for dosing at any time of the day without regard to meals. This added convenience, along with excellent healing of esophagitis and symptom relief, substantiate its use in patients with gastroesophageal reflux disease requiring PPI treatment.

Dexlansoprazole MR: a review

Dexlansoprazole MR is the R-enantiomer of lansoprazole that is delivered by a novel system, the dual delayed release formulation. The drug has been shown to be efficacious in healing erosive esophagitis as compared with lansoprazole. When compared to placebo, dexlansoprazole provided significantly higher maintenance rates for healed esophageal mucosa in patients with erosive esophagitis and symptom control in patients with non-erosive reflux disease. Dexlansoprazole could be taken without regard to food. Overall, dexlansoprazole is well tolerated and has a comparable side-effect profile to lansoprazole.

Dexlansoprazole: A proton pump inhibitor with a dual delayed-release system

BACKGROUND

Dexlansoprazole, the dextrorotatory enantiomer of lansoprazole, is a proton pump inhibitor (PPI) formulated to have dual delayed-release properties. It is indicated for healing all grades of esophagitis, maintaining the healing of erosive esophagitis (EE), and treating heartburn associated with nonerosive gastroesophageal reflux disease.

OBJECTIVE

This article reviews the pharmacology, pharmacokinetics, and pharmacodynamics of dexlansoprazole, as well as its clinical efficacy and tolerability.

METHODS

MEDLINE (1966-April 2010) and International Pharmaceutical Abstracts (1970-April 2010) were searched for original research and review articles published in English using the terms dexlansoprazole and TAK-390MR. The reference lists of identified articles were reviewed for additional pertinent publications. Abstracts from 2007-2009 American College of Gastroenterology and Digestive Disease Week meetings were searched using the same terms.

RESULTS

By irreversibly binding to H(+)K(+)-ATPase, dexlansoprazole inhibits acid production by the parietal cell. Its dual delayed-release formulation provides 2 distinct releases of medication, prolonging the mean residence time compared with lansoprazole (5.56-6.43 vs 2.83-3.23 hours, respectively). In 2 identical Phase III trials of the healing of EE, there were no significant differences in rates of complete healing after 8 weeks between dexlansoprazole 60 and 90 mg once daily and lansoprazole 30 mg once daily. In 2 studies of the maintenance of healing of EE, rates of healing at 6 months were significantly higher with dexlansoprazole 30, 60, and 90 mg once daily compared with placebo (P < 0.001). Patients with nonerosive reflux disease who received dexlansoprazole 30 or 60 mg once daily had significantly more 24-hour heartburn-free days compared with those who received placebo (P < 0.001). Dexlansoprazole was well tolerated compared with placebo or lansoprazole in all studies.

CONCLUSIONS

In the studies reviewed, dexlansoprazole was well tolerated and effective in the healing and maintenance of EE, and in the treatment of nonerosive reflux disease. However, most of the available evidence involved comparisons with placebo, making it difficult to draw meaningful conclusions about the place of dexlansoprazole among PPIs. More head-to-head comparative trials with other PPIs are needed to determine whether the unique formulation of dexlansoprazole translates into a clinically meaningful improvement in outcomes.

Dexlansoprazole modified release: in erosive oesophagitis and non-erosive reflux disease

Dexlansoprazole modified release (dexlansoprazole MR) is an orally administered delayed-release formulation of the R-enantiomer of the proton pump inhibitor lansoprazole that is effective in improving the healing of all grades of erosive oesophagitis, maintaining the healing of erosive oesophagitis and in the treatment of symptomatic non-erosive reflux disease (NERD). In two large, identical, 8-week, randomized, double-blind, multicentre phase III trials, dexlansoprazole MR 60 mg once daily achieved complete healing in >or=92% of patients with all grades of erosive oesophagitis (primary endpoint) and was noninferior to lansoprazole 30 mg once daily using life-table analysis. Moreover, in a randomized, double-blind, multicentre phase III trial in patients with healed erosive oesophagitis, dexlansoprazole MR 30 mg once daily was significantly more effective than placebo in maintaining healing following 6 months' treatment (primary endpoint). In addition, the proportion of 24-hour heartburn-free days (primary endpoint) was significantly greater in recipients of dexlansoprazole MR 30 mg once daily than in recipients of placebo following 4 weeks' treatment in a large, randomized, double-blind, multicentre phase III trial in patients with NERD. Dexlansoprazole MR 30 or 60 mg once daily was generally well tolerated in a pooled analysis of clinical trials of up to 12 months' duration.

Dexlansoprazole in the Treatment of Esophagitis and Gastroesophageal Reflux Disease

OBJECTIVE:

To describe the pharmacology, pharmacokinetics, and efficacy of dexlansoprazole in the treatment of heartburn associated with nonerosive gastroesophageal reflux disease (GERD) and healing and maintenance of healing of all grades of erosive esophagitis (EE).

DATA SOURCES:

Literature searches were conducted using MEDLINE Ovid (1950-December 2009, week 4) and EMBASE (1980-2009, week 53) using the term dexlansoprazole. References from articles obtained from the search were evaluated for other relevant citations.

STUDY SELECTION AND DATA EXTRACTION:

All articles published in English evaluating the pharmacology, pharmacokinetics, efficacy, and adverse effect profile of dexlansoprazole were selected for inclusion.

DATA SYNTHESIS:

Dexlansoprazole is the newest addition to the proton pump inhibitor (PPI) class and is approved for the treatment of heartburn associated with nonerosive GERD, healing of all grades of EE, as well as maintenance of healing of EE. Dexlansoprazole has a unique dual delayed-release formulation, which releases drug at 2 points in time; the first peak occurs 1-2 hours after administration and the second occurs within 4-5 hours after administration. In Phase 3 trials conducted in adults, researchers found that dexlansoprazole increases rates of healing of EE, as well as the maintenance of healing, compared to lansoprazole. Relief of heartburn symptoms was comparable among the dexlansoprazole and lansoprazole treatment groups. Common adverse effects of dexlansoprazole are similar to those of the other PPIs, including diarrhea, abdominal pain, nausea, upper respiratory infection, vomiting, and flatulence.

CONCLUSIONS:

Dexlansoprazole provides another treatment option for the management of EE and symptoms of heartburn. Considering that the cost of dexlansoprazole is not favorable, further studies evaluating potential advantages over other agents are necessary to define the role of dexlansoprazole in the treatment of these conditions.

CYP2C19 genotypes in the pharmacokinetics/pharmacodynamics of proton pump inhibitor-based therapy of Helicobacter pylori infection

IMPORTANCE OF THE FIELD

Proton pump inhibitors (PPIs) are potent gastric acid inhibitors. Therapies with a PPI and antibiotics are used to cure Helicobacter pylori (H. pylori) infection, which is closely related to many gastrointestinal diseases. Most PPIs are mainly metabolized by cytochrome 2C19 (CYP2C19). The genetic polymorphisms of CYP2C19 may lead to the differences in pharmacokinetics (PK), pharmacodynamics (PD) and clinical efficacy of PPIs.

AREAS COVERED IN THIS REVIEW

The roles of PPIs on the eradication of H. pylori are summarized. The impact f CYP2C19 polymorphism on the PK and PD of PPIs is addressed and related to the present status of therapy for H. pylori infection. The opinions on the strategy of PPIs-based therapies of H. pylori infection are provided.

WHAT THE READER WILL GAIN

Update the factors that may influence the PPIs-based therapies of H. pylori infection.

TAKE HOME MESSAGE

The eradication rates of H. pylori infection are significantly different between patients who are CYP2C19 extensive metabolizers and poor metabolizers, partly because of the differences in the PK and PD of PPIs. Nonetheless, the differences can be improved by adjusting the regimens of PPIs and using antibiotics that have less H. pylori-resistance.

Delayed release dexlansoprazole in the treatment of GERD and erosive esophagitis

Although proton pump inhibitors (PPI) have a record of remarkable effectiveness and safety in the management of gastroesophageal reflux disease (GERD), several treatment challenges with PPI have emerged. Dexlansoprazole MR is the (R)-enantiomer of lansoprazole contained in a formulation that produces two distinct releases of drug and significantly extends the duration of active plasma concentrations and % time pH > 4 beyond that of conventional single-release PPI. Dexlansoprazole MR can be administered without regard to meals or the timing of meals in most patients. Dexlansoprazole MR 60 mg demonstrated similar efficacy for healing of erosive esophagitis at 8 weeks compared with lansoprazole 30 mg, and dexlansoprazole MR 30 mg was superior to placebo for maintenance of healed erosive esophagitis at 6 months with 99% of nights and 96% of days heartburn-free over 6 months in patients taking dexlansoprazole MR 30 mg. Superior relief of heartburn occurred in patients taking dexlansoprazole MR 30 mg (55% heartburn-free 24-hour periods) vs placebo (14%) for symptomatic nonerosive GERD. The safety profile of dexlansoprazole MR is similar to that of lansoprazole. The extended pharmacodynamic effects, added convenience, and efficacy and safety of dexlansoprazole MR offer a novel approach to gastric pH control in patients with acid-related disorders.

Safety profile of dexlansoprazole MR, a proton pump inhibitor with a novel dual delayed release formulation: global clinical trial experience

BACKGROUND

Dexlansoprazole MR is a dual delayed release formulation of dexlansoprazole, an enantiomer of lansoprazole.

AIM

To assess safety of dexlansoprazole MR in phase 3 clinical trials.

METHODS

Data from 4270 patients receiving dexlansoprazole MR 30 mg (n = 455), 60 mg (n = 2311) or 90 mg (n = 1864); lansoprazole 30 mg (n = 1363); or placebo (n = 896) in six randomized controlled trials and a 12-month safety study were pooled. Safety was assessed via adverse events, vital signs, electrocardiograms, clinical laboratory results and gastric biopsies. Adverse events were summarized per 100 patient-months of exposure to account for imbalances in study drug exposure.

RESULTS

The number of patients with > or =1 treatment-emergent adverse event per 100 patient-months was higher in placebo (24.49) and lansoprazole (21.06) groups than in any dexlansoprazole MR (15.64-18.75) group. Fewer patients receiving dexlansoprazole MR discontinued therapy because of an adverse event (P < or = 0.05 vs. placebo). Seven patients died of events considered unrelated to study drug. Mean serum gastrin rose in all groups except placebo; increases were not dose-related. No clinically concerning trends were seen in gastric biopsy results. Endocrine cell hyperplasia, dysplasia and neoplasia were not observed.

CONCLUSION

Dexlansoprazole MR 30-90 mg has a safety profile comparable to that of lansoprazole.