Pharmacokinetics and pharmacodynamics of a known active PPI with a novel Dual Delayed Release technology, dexlansoprazole MR: a combined analysis of randomized controlled clinical trials

Mathematical model of the relationship between pH holding time and erosive esophagitis healing rates

Effective suppression of gastric acid secretion promotes healing of erosive esophagitis. Treatment guidelines recommend proton pump inhibitors (PPIs) and histamine H2-receptor antagonists (H2RAs). Emerging evidence also supports potassium-competitive acid blockers (P-CABs). The aim was to construct a mathematical model to examine the relationship between pH holding time ratios (HTRs) and erosive esophagitis healing rates with H2RAs, PPIs and P-CABs. By literature search, we identified studies of H2RAs, PPIs or P-CABs that reported mean pH >4 HTRs at steady state (days 5-8) and erosive esophagitis healing rates after 4 and/or 8 weeks. We aggregated treatments by drug class and developed a non-linear, mixed-effects model to explore the relationship between pH >4 HTRs and healing rates. The pH dataset included 82 studies (4297 participants; 201 dosage arms); healing rate data came from 103 studies (43,417 patients; 196 treatment arms). P-CABs achieved the longest periods with intragastric pH >4, and the highest healing rates after 4 and 8 weeks. The predicted probabilities of achieving ≥90% healing rates at 8 weeks were 74.1% for P-CABs, 17.3% for PPIs and 0% for H2RAs. P-CABs provide the longest duration with intragastric pH >4 and, accordingly, the highest healing rates of erosive esophagitis.

GERD: Latest update on acid-suppressant drugs

GERD is a very familiar diagnosis among health care providers due to its massive spread, and its symptoms can affect the quality of life for a respectable slice of its patients. Therefore, what can only be described as a logical consequence, a pursuit of a treatment that can both relieve symptoms and have minimal side effects is still ongoing to cover the large demographic affected by GERD. In the following review, analysis will be made of GERD, including possible regulatory activity, of certain drugs to the already discussed pathways involved in GERD patients.

Pharmacokinetic and pharmacodynamic exploration of various combinations of tegoprazan immediate and delayed-release formulations

AIMS

The new modified-release formulation of tegoprazan, a novel potassium-competitive acid blocker, is expected to improve the management of acid-related disease, including nocturnal acid breakthrough, by prolonging the duration of acid suppression. This study aimed to explore the pharmacokinetics (PK) and pharmacodynamics (PD) of various combinations of tegoprazan with immediate-release (IR) and delayed-release (DR) formulations.

METHODS

A three-cohort, open-label, randomized, single-dose, three-treatment, six-sequence, three-period crossover study was conducted. Various combinations of tegoprazan IR and DR formulations (50, 75 or 100 mg) were administered orally once per period. The 24-h intragastric pH was monitored before and after each administration. PK blood samples were collected for up to 48 h. PK and PD were compared among treatments.

RESULTS

Eighteen healthy Korean subjects completed the study. All treatment groups showed intragastric pH above 4 approximately 1 h following tegoprazan administration. Among the various combinations, the IR and DR combination at a 1:1 ratio induced greater gastric acid suppression (%Time pH ≥ 4) than IR alone in each dose group, both for 24 h (50 mg; 59% vs. 52%, P = .2188, 95% confidence interval [CI] -6.92-22.27, 100 mg; 85% vs. 70%, P < .05, 95% CI 8.92-22.19) and at night (50 mg; 27% vs. 16%, P = .1563, 95% CI -11.79-37.71, 100 mg; 77% vs. 49%, P < .05, 95% CI 16.14-42.98), with similar systemic exposure.

CONCLUSIONS

The combinatorial tegoprazan in the IR and DR 1:1 ratio formulation was found to induce stronger gastric acid suppression throughout the day and at night, compared to the conventional IR formulation.

Pharmacokinetics and Pharmacodynamics of Esomezol DR, a New Dual Delayed-Release Formulation of Esomeprazole 20 Mg or 40 Mg, in Healthy Subjects

Background

Esomeprazole, a proton pump inhibitor (PPI), is widely used to treat acid-related disorders, but it has short plasma half-life which can cause insufficient gastric acid suppression, such as nocturnal acid breakthrough. A new dual delayed-release (DR) formulation of esomeprazole (Esomezol DR), was developed to extend the duration of gastric acid suppression.

Purpose

This study aimed to evaluate the pharmacokinetics (PKs) and pharmacodynamics (PDs) of esomeprazole for the DR formulation compared to a conventional enteric-coated (EC) formulation (Nexium) in healthy male subjects.

Methods

Two randomized, open-label, multiple-dose, two-way crossover studies with esomeprazole 20 mg and 40 mg were conducted. Subjects received the DR formulation or the EC formulation once daily for 7 days in each period with a 7-day washout. Serial blood samples were collected up to 24 hours after the 1st dose, and 24-hour intragastric pH was continuously monitored before the 1st dose as baseline and after the 1st and the 7th dose.

Results

In 20 mg and 40 mg dose groups, 38 and 44 subjects completed the study, respectively. The DR formulation exhibited the dual-release pattern of esomeprazole, resulting in more sustained plasma concentration-time profiles compared to the EC formulation. The systemic exposure of esomeprazole for the DR formulation was comparable to that for the EC formulation, showing the similar area under the plasma concentration-time curve. The 24-hour gastric acid suppression was also similar between the two formulations, while the inhibition during night-time (22:00-06:00) showed a better tendency in the DR formulation.

Conclusion

The sustained exposure of esomeprazole in the DR formulation led to well-maintained and higher acid inhibition compared to the EC formulation, especially during the night-time. These results suggest that the DR formulation can be an alternative formulation to the conventional EC formulation, expecting the potential of relieving nocturnal acid-related symptoms.

Deciphering the nature of binding of dexlansoprazole with DNA: Biophysical and docking approaches

Drugs, in general, exhibit their pharmacological activity in binding with intracellular targets. Numerous anticancer and antibacterial drugs target DNA as one of their primary intracellular targets. Dexlansoprazole (DLP) is a heterocyclic compound containing benzimidazole moiety and a proton pump inhibitor used to treat gastroesophageal reflux disease. The interaction of dexlansoprazole with calf thymus DNA (ct-DNA) has been studied using biophysical methods. The UV-Visible studies revealed a binding constant of 2.15 ± 0.3 × 104 M^-1 which is close to the value of 2.44 ± 0.3 × 10⁴ M^-1 obtained from the fluorescence studies. Competitive displacement studies using the fluorescence spectroscopic method with ethidium bromide and Hoechst as DNA markers suggested the groove binding mode of DLP in ct-DNA. The groove binding mode of DLP in ct-DNA was complemented by the results of viscosity and DNA melting studies. Further studies on the effect of ionic strength and potassium iodide on DLP binding with ct-DNA supported the observed binding mode. Circular dichroism studies reflected no significant conformational variation in ct-DNA after the interaction. The binding mode obtained from the experimental studies was corroborated by the molecular docking studies that showed the position of DLP in the minor groove of ct-DNA along with the receptor interface restudies involved in the interaction.

Novel Esomeprazole Magnesium-Loaded Dual-Release Mini-Tablet Polycap: Formulation, Optimization, Characterization, and In Vivo Evaluation in Beagle Dogs

Esomeprazole magnesium (EMP) is a proton pump inhibitor (PPI) that reduces acid secretion. EMP has a short plasma half-life (approximately 1.3 h); hence, nocturnal acid breakthrough (NAB) frequently occurs, disturbing the patient’s nighttime comfort and sleep. We aimed to develop a novel esomeprazole magnesium-loaded dual-release mini-tablet polycap (DR polycap) with a prolonged onset time and improved bioavailability to prevent NAB. The formulation of the EPM mini-tablet core resulted in rapid drug release. The core was coated with an inner coating and an Eudragit^® L30D-55 aqueous dispersion coating to prepare the first-release mini-tablet. In addition, the core was coated with an inner coating and an aqueous dispersion of Eudragit^® S100 and Eudragit^® L100 coating to prepare the second-release mini-tablet. Each mini-tablet type was characterized using an in vitro dissolution test and microscopic examination. After testing, 10 of each mini-tablets were placed together in hard capsules to form DR polycaps. The combination of mini-tablets was optimized via in vitro release testing and in vivo pharmacokinetic studies. The AUC_0–24h of the DR polycap was similar to that of a comparable commercial product (Nexium^®); C_max was lower by approximately 50%, and T_max was extended by approximately 1.7-fold. In conclusion, DR polycap is an alternative to commercial products with improved NAB and dosing compliance because of its dual-release characteristics.

Management of patients with digestive diseases during the COVID-19 pandemic. Clinical Practice Guidelines by the Russian scientific medical society of internal medicine (RSMSIM) and the Gastroenterological Scientific Society of Russia (2nd edition)

The presented clinical practice guidelines of the Gastroenterological Scientific Society of Russia (GSSR), diagnostic, and therapeutic approaches for patients with digestive diseases during the COVID-19 pandemic. The guidelines were approved by the XXIII Congress of the GSSR and the 22nd International Slavonic-Baltic Scientifi c Forum “St. Petersburg - Gastro-2020 ON-LINE” (St. Petersburg, June 11, 2020). The presented clinical practice guidelines of the Russian Scientific Medical Society of Internal Medicine (RSMSIM) and the Gastroenterological Scientific Society of Russia (GSSR), diagnostic, and therapeutic approaches for patients with digestive diseases during the COVID-19 pandemic. The recommendations were approved at the XV National Congress of Internal Medicine, XXIII Congress of NOGR on the basis of the 1st edition, adopted at the 22nd International Slavic- Baltic Scientific Forum “St. Petersburg - Gastro-2020 ON-LINE”.

Comparison of the efficiency of two different proton pump inhibitor formula in treatment of patients with atypical gastroesophageal reflux disease: a prospective randomized study

BACKGROUND AND AIM

The prospective, open-label, randomized study aims to compare the efficacy of lansoprazole, a fast orally disintegrating proton pump inhibitor (PPI), and dexlansoprazole, a dual delayed release PPI, in patients with atypical symptoms of gastroesophageal reflux disease (GERD).

METHODS

Patients with atypical GERD symptoms with a total reflux symptom index score > 10 were eligible for enrollment. From February 2018 to December 2019, 232 subjects were randomly assigned (1:1 ratio) to receive oral lansoprazole, Takepron OD 30 mg, once daily before breakfast or oral dexlansoprazole, Dexilant 60 mg, once daily before breakfast for 8 weeks. The primary end-point is to compare the symptoms response rate after an 8-week PPI therapy between the two groups.

RESULTS

There were 232 study subjects enrolling in this study. After the 8-week PPI therapy, dexlansoprazole-treated group had a significantly higher response rate than lansoprazole-treated group in cough (76.5% vs 38.0%) and globus (69.7% vs 30.8%) (P all < 0.05 by intention-to-treat). Multivariate logistic regression analysis showed that the use of dexlansoprazole, presence of dyslipidemia, and typical GERD symptoms (acid reflux and heartburn) were predictors for symptom response for cough; the use of dexlansoprazole and presence of erosive esophagitis were predictors for symptom response for globus (P all < 0.05). No predictor for therapy response to hoarseness was noted.

CONCLUSIONS

There is a higher response rate for cough and globus symptoms in patients with atypical GERD after the 8-week PPI therapy with dexlansoprazole rather than lansoprazole.

The Physiology of the Gastric Parietal Cell

Parietal cells are responsible for gastric acid secretion, which aids in the digestion of food, absorption of minerals, and control of harmful bacteria. However, a fine balance of activators and inhibitors of parietal cell-mediated acid secretion is required to ensure proper digestion of food, while preventing damage to the gastric and duodenal mucosa. As a result, parietal cell secretion is highly regulated through numerous mechanisms including the vagus nerve, gastrin, histamine, ghrelin, somatostatin, glucagon-like peptide 1, and other agonists and antagonists. The tight regulation of parietal cells ensures the proper secretion of HCl. The H+-K+-ATPase enzyme expressed in parietal cells regulates the exchange of cytoplasmic H+ for extracellular K+. The H+ secreted into the gastric lumen by the H+-K+-ATPase combines with luminal Cl- to form gastric acid, HCl. Inhibition of the H+-K+-ATPase is the most efficacious method of preventing harmful gastric acid secretion. Proton pump inhibitors and potassium competitive acid blockers are widely used therapeutically to inhibit acid secretion. Stimulated delivery of the H+-K+-ATPase to the parietal cell apical surface requires the fusion of intracellular tubulovesicles with the overlying secretory canaliculus, a process that represents the most prominent example of apical membrane recycling. In addition to their unique ability to secrete gastric acid, parietal cells also play an important role in gastric mucosal homeostasis through the secretion of multiple growth factor molecules. The gastric parietal cell therefore plays multiple roles in gastric secretion and protection as well as coordination of physiological repair.

A comparison between dexlansoprazole modified release-based and lansoprazole-based nonbismuth quadruple (concomitant) therapy for first-line Helicobacter pylori eradication: a prospective randomized trial

PURPOSE

Steadily maintaining high intra-gastric PH is the major factor for successful Helicobacter pylori (H.pylori) eradication. It is important to search for a stronger PPI. Dexlansoprazole MR is a dual delayed release formulation PPI taken once daily which is capable of maintaining longer duration of high intra-gastric PH. It is very effective in treating gastroesophageal disease but reports on H, pylori eradication is very rare. This study sought to compare dexlansoprazole MR-based concomitant treatment and lansoprazole-based concomitant treatment in H. pylori infection and to investigate the factors that affect the eradication rates.

METHODS

Two hundred two participants with H. pylori infection were included and randomly assigned to seven days of dexlansoprazole MR-based concomitant therapy (dexlansoprazole MR 60 mg once daily, clarithromycin 500 mg twice daily, amoxicillin 1 g twice daily and metronidazole 500 mg twice daily; DACM group) or a seven days of lansoprazole-based concomitant therapy (lansoprazole 30 mg twice daily, clarithromycin 500 mg twice daily, amoxicillin 1 g twice daily, and metronidazole 500 mg twice daily; LACM group). The participants were asked to perform urea breath tests eight weeks later.

RESULTS

The eradication rates in the DACM group were 86.1% [95% confidence interval (CI): 77.8%-92.2%] in the ITT analysis and 90.6% (95% CI: 82.9%-95.6%) in the PP analysis, respectively, as compared with 90.1% (95% CI: 82.6%-95.2%) and 92.6% (95% CI: 85.5%-96.9%) (p=0.384 and p=0.572, respectively) in the LACM group for the same analyses. The adverse event rates were 11.5% in the DACM group and 10.2% in the LACM group (p=0.779).

CONCLUSION

As a first-line H. pylori treatment regimen, dexlansoprazole MR-based concomitant therapy attained a successful eradication rate of 90%, which was non inferior to that of lansoprazole-based concomitant treatment.

CLINICALTRIALSGOV IDENTIFIER

NCT03829150.

Efficacy of dexlansoprazole-based triple therapy for Helicobacter pylori infections

BACKGROUND

Dexlansoprazole has been shown to be efficacious for the treatment of gastroesophageal reflux disease. However, there is a paucity of data about its efficacy for Helicobacter pylori eradication. The aim of this study was to evaluate the efficacy of dexlansoprazole for H. pylori eradication as triple therapy in real-world practice.

METHODS

Adult patients with endoscopically proven H. pylori related peptic ulcer diseases or gastritis were recruited for this study. The eradication status was assessed based on the results of the 13C-urea breath test performed 4 weeks after treatment. According to the different treatment regimens, the patients were allocated to group A: Esomeprazole 40 mg b.i.d. + amoxicillin 1 g b.i.d. + clarithromycin 500 mg b.i.d. for 7 days; group B: Esomeprazole 40 mg q.d. + amoxicillin 1 g b.i.d. + clarithromycin 500 mg b.i.d. for 7 days, or group C: Dexlansoprazole 60 mg q.d. + amoxicillin 1 g b.i.d. + clarithromycin 500 mg b.i.d. for 7 days.

RESULTS

A total of 215 patients (49% males) were enrolled in this study, with a mean age of 55 years. The eradication rates in group A, B, and C were 94.7% (71/75), 89.6% (69/77), and 93.7% (59/63) (p = 0.457), respectively. The adverse events were similar between the three groups (p = 0.068).

CONCLUSIONS

This study suggests that dexlansoprazole-based triple therapy has an acceptable eradication rate for H. pylori infection.

Development of Dexlansoprazole Delayed-Release Capsules, a Dual Delayed-Release Proton Pump Inhibitor

Proton pump inhibitors (PPIs) are widely used for treating acid-related disorders. For an "ideal PPI," achieving maximal absorption and sustaining pharmacodynamic effects through the 24-h dosing cycle are critical features. Dexlansoprazole offers a relevant case study on how an improved PPI was developed capitalizing on the rational optimization of a precursor molecule-in this case, using lansoprazole as a starting point, leveraging its chemical properties on pharmacokinetics, and exploring optimized formulations. Dexlansoprazole is the R(+)-enantiomer of lansoprazole and shows stereoselective differences in absorption and metabolism compared with the racemic mixture of lansoprazole. The formulation was further refined to use pulsate-type granules with enteric coating to withstand acidic gastric conditions, while allowing prolonged absorption in the proximal and distal small intestine. As a result, the dual delayed-release formulation of dexlansoprazole has a plasma concentration-time profile characterized by 2 distinct peaks, leading to an extended duration of therapeutic plasma drug concentrations compared with the conventional delayed-release lansoprazole formulation. The dual delayed-release formulation maintains plasma drug concentrations longer than the lansoprazole delayed-release formulation at all doses.

Laryngopharyngeal reflux: clinical significance, modern approaches to diagnosis and treatment

Gastroesophageal reflux disease (GERD) is one of the most common pathologies in modern clinical practice. Laryngopharyngeal reflux (LPR) is considered to be an extraesophageal manifestation of GERD and is characterized by retrograde ingestion of gastric content into the larynx and pharynx, leading to recurrent otolaryngological symptoms. Classical manifestations of LPR are hoarseness, perspiration, dryness and feeling of lump in the throat, coughing. There is no «gold standard» for the diagnosis of LPR. At the same time, several instrumental methods are used in clinical practice to verify the diagnosis: laryngoscopy and EGDS are the most common, and in some cases - 24-hour pH-metry and impedancemetry. In the case of an established diagnosis of LPR, it is recommended to use a standard dosage of PPI twice a day for 3–6 months.

Dual Delayed-Release Dexlansoprazole for Healing and Maintenance of Healed Erosive Esophagitis: A Safety Study in Adolescents

BACKGROUND

In gastroesophageal reflux disease (GERD), the frequency of heartburn symptoms and erosive esophagitis (EE) increases with age in children and adolescents. Proton pump inhibitor, dexlansoprazole, is approved for healing EE of all grades, maintenance of healed EE, relief of heartburn, and treatment of symptomatic non-erosive GERD in patients ≥ 12 years.

AIM

To assess safety and efficacy of dexlansoprazole dual delayed-release capsule in healing of EE and maintenance of healed EE in adolescents.

METHODS

A multicenter, phase 2, 36-week study was conducted in 62 adolescents (12-17 years) with endoscopically confirmed EE. Patients received dexlansoprazole 60 mg once daily (QD) during open-label healing phase. Those with confirmed healing at week 8 were randomized to dexlansoprazole 30 mg QD or placebo during 16-week, double-blind maintenance phase, with subsequent treatment-free follow-up of ≥ 12 weeks. Primary endpoints were treatment-emergent adverse events (TEAEs) in ≥ 5% of patients during treatment. Secondary endpoints included percentages of patients with healing of EE and with maintenance of healed EE.

RESULTS

88% of patients achieved EE healing, and 61.3% reported a TEAE [headache (12.9%), oropharyngeal pain (8.1%), diarrhea (6.5%), and nasopharyngitis (6.5%)]. During maintenance phase, healing was maintained in 82% and 58% of dexlansoprazole and placebo groups, respectively. 72.0% of dexlansoprazole-treated patients reported TEAEs, which included headache (24.0%), abdominal pain (12.0%), nasopharyngitis (12.0%), pharyngitis (12.0%), sinusitis (12.0%), bronchitis (8.0%), upper respiratory tract infection (8.0%), and insomnia (8.0%); 61.5% experienced a TEAE with placebo.

CONCLUSIONS

Dexlansoprazole is safe and efficacious for healing EE and maintenance of healed EE in adolescents.

Bioavailability of dexlansoprazole delayed-release capsule granules when administered via nasogastric tube or orally via syringe

Objective

To assess the effect of route of administration on the bioavailability of dexlansoprazole 60 mg delayed-release capsule granules.

Methods

One open-label, Phase I, single-dose, 3-period crossover study was conducted in healthy adults. The bioavailability of Dexilant^® (dexlansoprazole) after dexlansoprazole capsule granules were mixed with water and administered via 16 French nasogastric tube or orally via syringe was compared to administration of the intact capsule in the fasted state, swallowed with water. Blood samples were collected before and after dosing to determine dexlansoprazole pharmacokinetic parameter estimates and plasma concentrations.

Results

Similar values for area under the plasma concentration-time curve and observed maximum plasma concentration were achieved when the dexlansoprazole 60 mg capsule was administered as the intact capsule or when the granules were mixed with water and administered via nasogastric tube or orally via syringe. The primary endpoints of maximum plasma concentration and area under the plasma concentration-time curve demonstrated bioequivalence when assessing these alternative routes of administration. Most adverse events were rated as mild and were comparable irrespective of administration route.

Conclusion

Systemic exposure to dexlansoprazole was equivalent regardless of administration route. The dexlansoprazole capsule was well tolerated.

Potent Potassium-competitive Acid Blockers: A New Era for the Treatment of Acid-related Diseases

Conventional proton pump inhibitors (PPIs) are used as a first-line therapy to treat acid-related diseases worldwide. However, they have a number of limitations including slow onset of action, influence by cytochrome P450 polymorphisms, unsatisfactory effects at night, and instability in acidic conditions. Alternative formulations of conventional PPIs have been developed to overcome these problems; however, these drugs have only introduced small advantages for controlling acid secretion compared to conventional PPIs. Potassium-competitive acid blockers (P-CABs) were developed and have beneficial effects including rapid, long-lasting, and reversible inhibition of the gastric hydrogen potassium ATPase, the proton pump of the stomach. Vonoprazan was recently innovated as a novel, orally active P-CAB. It is currently indicated for the treatment of gastric and duodenal ulcers, reflux esophagitis, and prevention of low-dose aspirin- or nonsteroidal anti-inflammatory drug-related gastric and duodenal ulcer recurrence in Japan. Vonoprazan does not require enteric coating as it is acid-stable, and it can be taken without food because it is quickly absorbed. Vonoprazan accumulates in parietal cells under both acidic and neutral conditions. It does not require an acidic environment for activation, has long-term stability at the site of action, and has satisfactory safety and tolerability. Thus, vonoprazan may address the unmet medical need for the treatment of acid-related diseases.

Interchangeable Use of Proton Pump Inhibitors Based on Relative Potency

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

Impact of Gastric H+/K+-ATPase rs2733743 on the Intragastric pH-Values of Dexlansoprazole Injection in Chinese Subjects

Background: Not all patients with acid-related disorders receiving proton pump inhibitor (PP) treatment get adequate gastric pH control. The genetic variation of receptors, metabolic enzymes, and transporters are known to cause failures of therapies. We have conducted a study to evaluate the influence of gastric H⁺/K⁺-ATPase, CYP2C19, and ABCB1 polymorphisms on the pharmacokinetic and pharmacodynamic profiles of dexlansoprazole injection in healthy Chinese subjects.

Methods: A total of 51 subjects were enrolled for pharmacokinetic and pharmacodynamic study after a single intravenous administration of 20 or 30 mg dexlansoprazole. Plasma concentrations were determined using a chiral liquid chromatography-mass spectrometry method. The intragastric pH and baseline-adjusted intragastric pH parameters were introduced to evaluate the pharmacodynamic characters. Genotyping was performed by polymerase chain reaction.

Results: The pharmacokinetic parameters were significantly influenced by CYP2C19 phenotypes, and gastric acid secretion inhibition were affected by both gastric H⁺/K⁺-ATPase and CYP2C19 polymorphisms. Gastric H⁺/K⁺-ATPase genotypes had greater effects than CYP2C19 genotypes on the suppression of gastric acid secretion.

Conclusion: Gastric H⁺/K⁺-ATPase polymorphism may be one of the main reasons that cause insufficient gastric acid inhibition.

25 Years of Proton Pump Inhibitors: A Comprehensive Review

Proton pump inhibitors (PPIs) were clinically introduced more than 25 years ago and have since proven to be invaluable, safe, and effective agents for the management of a variety of acid-related disorders. Although all members in this class act in a similar fashion, inhibiting active parietal cell acid secretion, there are slight differences among PPIs relating to their pharmacokinetic properties, metabolism, and Food and Drug Administration (FDA)-approved clinical indications. Nevertheless, each is effective in managing gastroesophageal reflux disease and uncomplicated or complicated peptic ulcer disease. Despite their overall efficacy, PPIs do have some limitations related to their short plasma half-lives and requirement for meal-associated dosing, which can lead to breakthrough symptoms in some individuals, especially at night. Longer-acting PPIs and technology to prolong conventional PPI activity have been developed to specifically address these limitations and may improve clinical outcomes.

Bioavailability of a dexlansoprazole delayed-release orally disintegrating tablet: effects of food and mode of administration

Background

Dexlansoprazole is a proton pump inhibitor (PPI) approved for use in dual delayed-release capsule and orally disintegrating tablet (ODT) formulations.

Aim

To assess effects of food, water, and route of administration on the bioavailability of dexlansoprazole 30-mg ODT.

Methods

Two separate open-label, phase 1, single-dose crossover studies were conducted in healthy adults. In study 1, pharmacokinetic parameters were analyzed in participants receiving dexlansoprazole ODT in a fed or fasted state with and without water. In study 2, the bioavailability of dexlansoprazole after administration via oral syringe or nasogastric (NG) tube, or after swallowing intact with water was compared to ODT administration in the fasted state, swallowed without water. Blood samples for determining dexlansoprazole plasma concentrations and pharmacokinetic parameter estimates were collected before and after dosing.

Results

Equivalent values for area under the plasma concentration–time curve (AUC) were observed in the fed and fasted states, but the maximum observed plasma concentration (C_max) was 38% lower in the fed state; therefore, bioequivalence was not achieved. A water rinse following standard ODT administration decreased dexlansoprazole bioavailability, with lower C_max and AUC values than when ODT was administered without a water rinse. Bioequivalence was demonstrated when comparing the alternative routes of administration, including via oral syringe or NG tube with standard ODT administration. Unlike with a water rinse, bioequivalence to standard ODT administration (i.e., without water) was demonstrated when swallowing the ODT intact with water. Rates of adverse events were comparable irrespective of administration route in the fasted state (6.7%–9.3%) and were 12% higher in the fed state than in the fasted state.

Conclusion

The AUC from the dexlansoprazole ODT was equivalent when administered in the fed and fasted states. Equivalent systemic exposure to dexlansoprazole was achieved regardless of the administration route.

The role of dexlansoprazole modified-release in the management of gastroesophageal reflux disease

Dexlansoprazole modified-release (MR) is the R-enantiomer of lansoprazole and is currently the only proton-pump inhibitor (PPI) with a novel dual delayed release (DDR) formulation. Overall, dexlansoprazole MR demonstrates a similar safety and side-effect profile as lansoprazole. Dexlansoprazole MR has been shown to be highly efficacious in healing erosive esophagitis, maintaining healed esophageal mucosa in patients with erosive esophagitis and controlling symptoms of patients with nonerosive reflux disease (NERD). Recent studies have also demonstrated that dexlansoprazole MR is highly effective in improving nocturnal heartburn, gastroesophageal reflux disease (GERD) related sleep disturbances and bothersome regurgitation. Dexlansoprazole MR is well tolerated and can be taken without regard to food.

Dexlansoprazole for Heartburn Relief in Adolescents with Symptomatic, Nonerosive Gastro-esophageal Reflux Disease

BACKGROUND

Proton pump inhibitors are commonly used to treat gastro-esophageal reflux disease (GERD) and nonerosive GERD (NERD) in adolescents and adults. Despite the efficacy of available medications, many patients have persisting symptoms, indicating a need for more effective agents.

AIMS

To assess the safety and efficacy of dexlansoprazole dual delayed-release capsules in adolescents for treatment of symptomatic NERD.

METHODS

A phase 2, open-label, multicenter study was conducted in adolescents aged 12-17 years. After a 21-day screening period, adolescents with endoscopically confirmed NERD received a daily dose of 30-mg dexlansoprazole for 4 weeks. The primary endpoint was treatment-emergent adverse events (TEAEs) experienced by ≥5% of patients. The secondary endpoint was the percentage of days with neither daytime nor nighttime heartburn. Heartburn symptoms and severity were recorded daily in patient electronic diaries and independently assessed by the investigator, along with patient-reported quality of life, at the beginning and end of the study.

RESULTS

Diarrhea and headache were the only TEAEs reported by ≥5% of patients. Dexlansoprazole-treated patients (N = 104) reported a median 47.3% of days with neither daytime nor nighttime heartburn. Symptoms such as epigastric pain, acid regurgitation, and heartburn improved in severity for 73-80% of patients. Pediatric Gastroesophageal Symptom and Quality of Life Questionnaire-Adolescents-Short Form symptom and impact subscale scores (scaled 1-5) each decreased by an average of 0.7 units at week 4.

CONCLUSIONS

Use of 30-mg dexlansoprazole in adolescent NERD was generally well tolerated and had beneficial effects on improving heartburn symptoms and quality of life.

TRIAL REGISTRATION

This study has the ClinicalTrials.gov identifier NCT01642602.

Bioavailability, safety, and pharmacodynamics of delayed-release dexlansoprazole administered as two 30 mg orally disintegrating tablets or one 60 mg capsule

BACKGROUND

Dual delayed-release dexlansoprazole is approved for use in adults as a 30 mg orally disintegrating tablet (ODT) or as 30 mg and 60 mg capsules. The pharmacokinetics, pharmacodynamics, and safety profile of two dexlansoprazole 30 mg ODTs were compared with one dexlansoprazole 60 mg capsule in this randomized, phase I, open-label, single-center, multiple-dose, two-period crossover study.

METHODS

Participants were randomized in one of two treatment sequences, each comprised two 5-day treatment periods during which two dexlansoprazole 30 mg ODTs or one 60 mg capsule was administered once daily. Pharmacokinetic parameters and the mean intragastric pH profile for the 24-hour period after dosing on days 1 and 5 were described. Adverse events were monitored during study duration and followed up with a phone call 5-10 days after the last dose of study drug.

RESULTS

On day 1, peak observed plasma concentration (Cmax) values were similar between two 30 mg ODTs (1047 ng/ml) and one 60 mg capsule (1164 ng/ml). Systemic exposure, measured by the area under the plasma concentration-time curve (AUC), was approximately 25% lower after ODT administration. On day 5, mean pH after daily doses of two 30 mg ODT or one 60 mg capsule was 4.33 and 4.36, respectively; both regimens maintained intragastric pH above 4.0 for 60% of the 24-hour period. Headache was the most commonly reported adverse event (observed in 19.2% of participants); no adverse events leading to study withdrawal occurred.

CONCLUSIONS

While systemic exposure (AUC) was 25% lower with ODT, peak concentrations (Cmax) after administration of two dexlansoprazole 30 mg ODTs and one 60 mg capsule were similar. The 24-hour intragastric pH control after administration of two dexlansoprazole 30 mg ODTs was equivalent to one dexlansoprazole 60 mg capsule. Both ODT and capsule were well tolerated.

Pharmacokinetics and pharmacodynamics of an orally disintegrating tablet formulation of dexlansoprazole

BACKGROUND

The pharmacokinetics and pharmacodynamics of a novel orally disintegrating tablet (ODT) formulation of delayed-release dexlansoprazole 30 mg was evaluated versus the dexlansoprazole 30 mg capsule in this phase I, open-label, multiple-dose, randomized, two-period crossover study.

METHODS

Healthy adults received daily doses of 30 mg dexlansoprazole ODT or 30 mg dexlansoprazole delayed-release capsule for 5 days during two treatment periods, separated by a 7-day washout interval. Blood samples for dexlansoprazole plasma concentrations and intragastric pH measurements were collected through 24 hours postdose on days 1 and 5 of each period.

RESULTS

Bioequivalence between the 30 mg ODT and 30 mg capsule dosage forms was demonstrated by the primary endpoints of dexlansoprazole peak concentration (C_max) and systemic exposure (AUC) values contained within the prespecified 90% confidence interval (CI) range of 0.80-1.25. Additional primary endpoints of intragastric mean pH values and percentage of time with pH > 4 over the 24-hour postdose interval were equivalent for dexlansoprazole ODT and dexlansoprazole capsule. Treatment-emergent adverse events were reported in 23% and 28% of participants receiving the ODT and capsule formulations, respectively. Headache was the most common adverse event in both treatment regimens (5.8% with ODT and 6.0% with capsule).

CONCLUSIONS

Administration of dexlansoprazole 30 mg ODT or 30 mg capsule provided equivalent plasma exposure when either was administered as a single dose or as once daily doses for 5 days. Pharmacodynamic equivalence between the two formulations was demonstrated by similar intragastric pH parameters on both day 1 and day 5. No effect of day on dexlansoprazole pharmacokinetics was observed. Dexlansoprazole ODT and dexlansoprazole capsule were both well tolerated.

Dexlansoprazole: delayed-release orally disintegrating tablets for the treatment of heartburn associated with non-erosive gastroesophageal reflux disease and the maintenance of erosive esophagitis

Gastroesophageal reflux disease (GERD) is a common condition afflicting millions of patients, whose prevalence continues to rise owing to the aging population and increasing burden of comorbid conditions, such as obesity. Currently, the mainstay of therapy for GERD is treatment with proton pump inhibitors (PPIs), which have proven efficacy, safety, and tolerability. Despite this, a considerable number of patients have refractory symptoms to PPI therapy. Dexlansoprazole is a new addition to the class of PPIs, which has a unique dual delayed drug release system, which aims to address the current limitations of acid suppressive therapy by offering extended acid suppression and improved ease of administration. Areas covered: This manuscript covers the pharmacokinetics, pharmacodynamics, clinical efficacy, and regulatory approval of dexlansoprazole. Additionally, there is further discussion concerning the current market settings and the potential future impact of dexlansoprazole. Expert commentary: Overall, dexlansoprazole offers benefits in its ease of administration and proven efficacy in the healing, maintenance of erosive esophagitis, and symptomatic non-erosive GERD. Long-term, dexlansoprazole will likely find a niche market among patients who fail other acid suppressive therapy or who desire simplified administration for compliance concerns, but will likely come at a higher out of pocket expense than comparable generic PPIs.

Pharmacological and Safety Profile of Dexlansoprazole: A New Proton Pump Inhibitor - Implications for Treatment of Gastroesophageal Reflux Disease in the Asia Pacific Region

Although gastroesophageal reflux disease is not as common in Asia as in western countries, the prevalence has increased substantially during the past decade. Gastroesophageal reflux disease is associated with considerable reductions in subjective well-being and work productivity, as well as increased healthcare use. Proton pump inhibitors (PPIs) are currently the most effective treatment for gastroesophageal reflux disease. However, there are limitations associated with these drugs in terms of partial and non-response. Dexlansoprazole is the first PPI with a dual delayed release formulation designed to provide 2 separate releases of medication to extend the duration of effective plasma drug concentration. Dexlansoprazole has been shown to be effective for healing of erosive esophagitis, and to improve subjective well-being by controlling 24-hour symptoms. Dexlansoprazole has also been shown to achieve good plasma concentration regardless of administration with food, providing flexible dosing. Studies in healthy volunteers showed no clinically important effects on exposure to the active metabolite of clopidogrel or clopidogrel-induced platelet inhibition, with no dose adjustment of clopidogrel necessary when coprescribed. This review discusses the role of the new generation PPI, dexlansoprazole, in the treatment of gastroesophageal reflux disease in Asia.

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.

Titanium Salan/Salalen Complexes: The Twofaced Janus of Asymmetric Oxidation Catalysis

Optically pure chiral epoxides and sulfoxides are ubiquitous building blocks in fine organic synthesis, employed in the pharmaceutical, agrochemical, and cosmetic industries. On the road to chiral epoxides and sulfoxides, efficient and stereoselective transition metal-based catalysts are the most promising guides. Among transition metals, we favor titanium for its cheapness and availability, nontoxicity, and well-known ability to catalyze a variety of stereoselective transformations, including oxidations with environmentally benign H2O2. In this personal account, we summarize the state-of-the-art of rational design of chiral titanium(IV) salan and salalen catalysts, and investigations of their catalytic reactivities and stereoselectivities in the epoxidations of olefins and oxidations of thioethers, unraveling the peculiarities and mechanisms of their catalytic action.

A Pilot Randomized Controlled Study of Dexlansoprazole MR-Based Triple Therapy for Helicobacter Pylori Infection

Dexlansoprazole MR is the R-enantiomer of lansoprazole that is delivered by a dual delayed release formulation. It is effective for symptom control of patients with gastroesophageal reflux disease. However, its efficacy in the treatment of Helicobacter pylori infection remains unclear. This pilot, randomized, controlled, head-to-head study was conducted to investigate whether the efficacy of single-dose dexlansoprazole MR-based triple therapy was noninferior to double-dose rabeprazole-based triple therapy in the treatment of H pylori infection. Consecutive H pylori-infected subjects were randomly allocated to either 7-day dexlansoprazole MR-based standard triple therapy (dexlansoprazole MR 60 mg once daily, clarithromycin 500 mg twice daily, and amoxicillin 1 g twice daily) or rabeprazole-based triple therapy (rabeprazole 20 mg twice daily, clarithromycin 500 mg twice daily, and amoxicillin 1 g twice daily). H pylori status was assessed 6 weeks after the end of treatment. A total of 177 H pylori-infected patients were randomized to receive dexlansoprazole MR-based (n = 90) or rabeprazole-based (n = 87) triple therapy. Intention-to-treat analysis demonstrated no differences between eradication rates of the 2 study groups (83.3% vs 81.6%; P = 0.736). Per-protocol analysis yielded comparable results (85.1% vs 81.2%; P = 0.497). Both groups exhibited similar frequencies of adverse events (7.8% vs 4.6%; P = 0.536) and drug compliance (98.9% vs 97.7%; P = 0.496). Multivariate analysis disclosed that the presence of clarithromycin resistance was the only independent factors predictive of treatment failure with an odds ratio of 6.8 (95% confidence interval: 1.2-37.6). This work demonstrates that single-dose dexlansoprazole MR-based triple therapy yields a similar eradication rate as double-dose rabeprazole-based therapy. Since the pharmaceutical cost of the single-dose dexlansoprazole MR regime is lower than that of the double-dose rabeprazole regimen, dexlansoprazole-based therapy can reasonably be recommended in the first-line treatment of H pylori infection.

Managing gastroesophageal reflux disease - comparative efficacy and outcomes of dexlansoprazole MR

The management of gastroesophageal reflux disease (GERD) has been revolutionized with the development of proton pump inhibitors (PPIs). Unfortunately, due to the inherent pharmacokinetic and pharmacodynamic profiles of conventional PPIs, many patients continue to suffer from symptoms related to GERD despite appropriate use of PPIs. Dexlansoprazole MR is a PPI with a unique dual delayed-release delivery system that has been designed to address the unmet needs in GERD management. Specifically, dexlansoprazole MR addresses limitations with short plasma half-life and need for meal-associated dosing, characteristic of conventional PPIs. In addition, dexlansoprazole MR has been shown to be effective in several specific clinical situations. These include coadministration with clopidogrel, healing of all grades of erosive esophagitis, improvement in reflux-related quality of life, step down to once-per-day dosing, and treatment of Helicobacter pylori infections. Furthermore, dexlansoprazole MR has been found to induce symptom improvement in patients with nonerosive esophageal reflux disease, nocturnal heartburn and GERD-related sleep disturbance, and regurgitation. Overall, dexlansoprazole MR is a unique and useful tool in the management of GERD.

Potassium-Competitive Acid Blockers (P-CABs): Are They Finally Ready for Prime Time in Acid-Related Disease?

The need for new acid suppressing agents with improved pharmacology and superior antisecretory effects to address unmet clinical needs in acid-related disorders has been evident for over a decade. Recent new antisecretory drugs (IR-omeprazole and MR-dexlansoprazole) only provide a small incremental advance in control of acid secretion over the delayed-release proton pump inhibitors. Vonoprazan (a new potassium-competitive acid blocker) displays more potent and extended 24 h acid suppression and preliminary Japanese trials translate this into meaningful clinical benefits in gastro-esophageal reflux disease and Helicobacter pylori eradication. We review the vonoprazan information to date and the indications, benefits, and concerns of more effective therapeutic control of acid secretion.

Pharmacokinetics and safety of dexlansoprazole MR in pediatric patients with symptomatic gastroesophageal reflux disease

OBJECTIVE

To evaluate the safety and pharmacokinetic profile of dexlansoprazole modified-release (MR) capsules in pediatric patients with symptomatic gastroesophageal reflux disease (GERD).

METHODS

This Phase I, open-label study enrolled male and female patients (1 to 11 years of age) with GERD. Patients received dexlansoprazole MR 15 mg, 30 mg, or 60 mg (according to weight) once daily for 7 days. Blood samples for the measurement of plasma dexlansoprazole concentrations were collected for 24 hours after the day 7 dose. Dexlansoprazole plasma concentrations and pharmacokinetic parameters were summarized by dose group. Safety assessments included adverse events (AEs), clinical laboratory evaluations, fasting gastrin concentrations, physical examinations, electrocardiograms, and vital signs.

RESULTS

Thirty-six patients received study drug (12 per dose group), and 31 had evaluable pharmacokinetic data. There was a significant effect of weight on dose-normalized area under the curve (AUC, P=0.003) and dose-normalized maximum plasma concentration (Cmax) (P=0.013), indicating that for a given dose, dexlansoprazole exposure decreases as body weight increases. After adjusting for body weight, both dexlansoprazole Cmax and AUC increased in an approximately dose-proportional manner with increasing dexlansoprazole dose. A total of ten of 36 patients reported at least one treatment-emergent AE, with most events considered mild in intensity. The most common AEs were vomiting, abdominal pain, diarrhea, and nausea.

CONCLUSION

In 1- to 11-year-old patients with symptomatic GERD, weight-adjusted dexlansoprazole AUC and Cmax increased approximately dose-proportionally. However, for a given dose, dexlansoprazole exposure decreased with increasing body weight. Dexlansoprazole MR was well tolerated, and the incidence of AEs did not increase with increasing dose.

High-dose extended-release lansoprazole (dexlansoprazole) and amoxicillin dual therapy for Helicobacter pylori infections

BACKGROUND

Helicobacter pylori infections have become increasingly difficult to treat.

AIM

To examine whether amoxicillin and high-dose dexlansoprazole would reliably achieve an H. pylori eradication rate of ≥90%.

METHODS

An open-label prospective pilot study of H. pylori eradication in treatment-naïve subjects with active H. pylori infection (positive by two tests).

THERAPY

amoxicillin 1 g and dexlansoprazole 120 mg each twice a day at approximately 12-hour intervals for 14 days. Success was accessed by urea breath test. An effective therapy was defined as a per-protocol treatment success of 90% or greater; treatment success of 80% or less was prespecified as an unacceptable result.

RESULTS

After 13 subjects were entered (12 men, one woman; average age of 54 years), the prespecified stopping rule of six treatment failures was achieved (i.e., the 95% confidence interval excluded achieving the required 90% success rate even if the proposed study of 50 completed patients were entered) and enrollment was stopped. Per-protocol and intention-to-treat treatment success were both 53.8%; (7/13); 95% CI = 25-80%. Compliance was 100%. Three patients (23%) reported side effects, all of which were mild and none interrupted therapy.

CONCLUSION

Theoretically, dual PPI plus amoxicillin should reliably eradicate H. pylori provided nearly neutral intragastric pH can be maintained. Clearly, dexlansoprazole, despite being administered at high dose and twice a day (i.e., total daily dose 240 mg), failed to achieve an intragastric milieu consistent with dual PPI plus amoxicillin therapy being an effective anti-H. pylori regimen.

Efficacy, safety, and tolerability of pantoprazole magnesium in the treatment of reflux symptoms in patients with gastroesophageal reflux disease (GERD): a prospective, multicenter, post-marketing observational study

BACKGROUND

To improve proton pump inhibitor effects, pharmacological modifications have been developed such as the use of enantiomer molecules (e.g., S-omeprazole, S-pantoprazole, or dexlansoprazole), or addition of NaHCO3 (for an immediate release) or magnesium (with a lower absorption for a more sustained effect).

OBJECTIVE

The objective of this study was to assess the efficacy, safety, and tolerability of pantoprazole magnesium 40 mg once daily for 4 weeks, on the relief of reflux symptoms in gastroesophageal reflux disease (GERD) patients.

METHODS

A phase IV, open-label, prospective, multicenter study was designed. Patients included were prescribed pantoprazole magnesium 40 mg orally once daily for 28±2 days. All patients had a history of persistent or recurrent heartburn and/or acid regurgitation for at least 3 months. Effectiveness and tolerability data obtained from patients who completed a minimum of 4 weeks of pantoprazole magnesium treatment were considered for analysis.

RESULTS

The account of baseline characteristics and demographics of GERD symptom intensity was made by analyzing the group of 4,343 patients that fulfilled all inclusion criteria; 54% were females (n=2,345) and 46% (n=1,998) males, with a mean age of 36.2±7.5 years. Severity of symptoms, assessed by the physician using the 4-point Likert scale, reduced by at least 80% from baseline intensity after treatment in the per protocol population. In the case of the intention-to-treat population, the improvement in symptom intensity was 73%. The number of patients that experienced any adverse events was 175/5,027 (3.48%).

CONCLUSIONS

Pantoprazole magnesium is a safe, effective, and well-tolerated drug that significantly improves GERD symptoms.

The effects of increasing body mass index on heartburn severity, frequency and response to treatment with dexlansoprazole or lansoprazole

BACKGROUND

Higher body mass index (BMI) is a recognised risk factor for gastro-oesophageal reflux disease (GERD). Data regarding the impact of BMI on proton pump inhibitor (PPI) therapy are conflicting.

AIM

To assess the impact of BMI on baseline heartburn symptom severity and frequency and response to PPI therapy in patients with non-erosive GERD (NERD) or erosive oesophagitis (EO).

METHODS

In post hoc analyses of phase 3 trial data, 621 NERD and 2692 EO patients were stratified by BMI (<25, 25 to <30 and ≥30 kg/m(2) ). NERD patients received either dexlansoprazole MR 30 mg or placebo daily for 4 weeks. EO patients received either dexlansoprazole MR 60 mg or lansoprazole 30 mg for 8 weeks. Symptom frequency and severity were assessed at baseline and subsequently by daily diary.

RESULTS

In both the NERD and EO cohorts, baseline heartburn severity increased with increasing BMI. The impact of PPI therapy on the reduction in heartburn symptom frequency and severity in both NERD and EO patients was similar across BMI categories. EO healing rates in patients treated with dexlansoprazole but not lansoprazole were higher in obese patients compared with those with a BMI <30 kg/m(2) . Differences between the PPIs were small.

CONCLUSIONS

The PPIs evaluated in this study reduced the frequency and severity of 24-h heartburn regardless of baseline BMI. In addition, because patients with higher BMI have more severe symptoms at baseline, they may experience greater therapeutic gain with dexlansoprazole (NERD and erosive oesophagitis) and possibly lansoprazole (erosive oesophagitis) treatment.

Absorption, distribution, metabolism and excretion of [14C]dexlansoprazole in healthy male subjects

BACKGROUND AND OBJECTIVE

The proton pump inhibitor dexlansoprazole is a modified-release formulation of dexlansoprazole, an enantiomer of lansoprazole, which employs a Dual Delayed Release™ (DDR) delivery system. This study was conducted in healthy subjects to assess the absorption, distribution, metabolism and excretion of a 60 mg dose of [14C]dexlansoprazole.

METHODS

After multiple daily doses of dexlansoprazole DDR for 4 days followed by a single dose of [14C]dexlansoprazole on day 5, absorption, distribution, metabolism and elimination of [14C]dexlansoprazole were assessed in six healthy male subjects whose CYP (cytochrome P450) 2C19 metabolizer status was also determined.

RESULTS

Five subjects were phenotyped as extensive metabolizers (EMs) and one subject was a poor metabolizer (PM). Recovery of radioactivity in urine and faeces averaged 98% after 7 days (51% in urine and 48% in faeces) post-14C dosing. In plasma, dexlansoprazole was the largest component detected, with the main metabolites in the EM subjects being 5-glucuronyloxy dexlansoprazole and 5-hydroxy dexlansoprazole (CYP2C19 mediated), whereas the PM subject had greater amounts of dexlansoprazole sulfone (CYP3A mediated). Dexlansoprazole was not detected in urine; six metabolites were identified accounting for an average of 86% of the urinary radioactivity, with 5-glucuronyloxy dexlansoprazole, 5-glucuronyloxy dexlansoprazole sulfide, 2-S-N-acetylcysteinyl benzimidazole and 5-sulfonyloxy dexlansoprazole sulfide being the primary metabolites. In faeces, parent drug and six identified metabolites accounted for 23% and 72%, respectively, of the faecal radioactivity, with 5-hydroxy dexlansoprazole sulfide and dexlansoprazole sulfide being predominant.

CONCLUSION

Overall, the results indicate that [14C]dexlansoprazole was well absorbed and extensively metabolized by oxidation, reduction and conjugation to 13 identified metabolites.

Evolving pharmacological approaches in gastroesophageal reflux disease

INTRODUCTION

Proton pump inhibitors (PPIs) have considerably improved quality of life in patients with gastroesophageal reflux disease (GERD). However, many patients remain symptomatic despite standard PPI therapy.

AREAS COVERED

This review focuses on evolving therapeutic strategies related to the pathophysiological processes of GERD and insufficient response to PPIs. Several clinical trials evaluated new PPI formulations and newer types of acid-suppressive drugs. These studies have evaluated traditional end points in GERD, but have not shown clinical superiority to current PPIs. Novel therapeutic strategies targeting underlying mechanisms of GERD, such as transient lower esophageal sphincter relaxations (TLESRs) and esophageal hypersensitivity, are being developed for add-on therapy to PPIs. Prokinetic drugs may also have some potential in the add-on treatment of GERD with insufficient response to PPIs. Add-on studies are hampered by insufficient information on optimal patient selection and lack of established end points.

EXPERT OPINION

Newer drugs for symptomatic control in GERD have largely focused on improved acid suppression, without evidence of clinical superiority. Drugs targeting esophageal motility and sensitivity to be used as add-onc therapy in PPI insufficient responders have not reached Phase III trials to date, due to difficulties with patient selection, tolerability and end points.

Maintenance of heartburn relief after step-down from twice-daily proton pump inhibitor to once-daily dexlansoprazole modified release

BACKGROUND & AIMS

Many patients with gastroesophageal reflux disease (GERD) take a proton pump inhibitor (PPI) twice daily to control symptoms. Once-daily dexlansoprazole modified release (MR) has a dual-delayed release formulation, making it attractive for step-down management of patients whose symptoms are well controlled on twice-daily PPIs. We investigated whether step-down to once-daily dexlansoprazole controls heartburn in patients with GERD who were receiving twice-daily PPI therapy.

METHODS

Patients 18 years and older taking a twice-daily PPI for symptom control were enrolled (n = 178) in a single-blind, multicenter study; 163 patients completed the study and 142 patients met criteria for the efficacy analysis. During the 6-week screening and treatment periods, patients recorded the presence of heartburn symptoms twice daily in electronic diaries. Patients' heartburn was considered well controlled if they had an average of 1 symptom or fewer per week during the last 4 weeks of screening and treatment. After screening, qualified patients were switched to masked dexlansoprazole MR 30 mg and placebo for 6 weeks. The primary efficacy end point was the proportion of patients whose heartburn remained well controlled after step-down. GERD-related symptoms and quality of life (QOL) also were evaluated using the Patient Assessment of Upper Gastrointestinal Disorders Symptom Severity Index (PAGI-SYM) and the PAGI-QOL questionnaires, respectively.

RESULTS

After step-down to once-daily dexlansoprazole MR 30 mg, heartburn remained well controlled in 88% of patients (125 of 142). These patients were able to maintain their GERD-related symptom severity and QOL, indicated by marginal changes in the PAGI-SYM and PAGI-QOL total and subscale scores, respectively.

CONCLUSIONS

Most patients with GERD who take twice-daily PPI to control heartburn are able to successfully step down to once-daily dexlansoprazole 30 mg.

Recent safety concerns with proton pump inhibitors

There have been recent concerns about the safety of proton pump inhibitors (PPIs). We focus here on 3 specific concerns-the possible interaction between PPIs and clopidogrel, the postulated link between PPI use and fractures, and the possibility that long-term PPI use might lead to hypomagnesemia. There is evidence for an in vitro interaction between clopidogrel and at least some PPIs. The Food and Drug Administration (FDA) has warned against the use of certain PPIs by patients on clopidogrel. However, a randomized controlled trial that compared clopidogrel alone with the combination of clopidogrel and omeprazole found no increase in adverse cardiovascular outcomes and a reduction in the rate of adverse gastrointestinal outcomes attributable to omeprazole. PPI use may be a weak risk factor for certain fractures, but the quality of evidence is relatively poor and there is a strong possibility of confounding. The mechanism whereby PPI use might increase fracture risk is unknown. Currently, no additional measures concerning calcium supplementation or bone mineral density monitoring are recommended for patients on a PPI. The FDA has suggested monitoring serum magnesium levels in patients on PPI therapy. The mechanism and frequency of PPI-induced hypomagnesemia are unclear. PPI treatment should not be withheld from patients who genuinely require it, but the PPI should be taken in the lowest effective dose and only for as long as clinically indicated. The same is, of course, true for all medicines. The benefits of PPI therapy greatly outweigh the risks.

Pharmacokinetics and safety of dexlansoprazole MR in adolescents with symptomatic GERD

OBJECTIVES

Dexlansoprazole MR 30  mg once daily (QD) is approved in adults for the treatment of symptomatic nonerosive gastroesophageal reflux disease (GERD) and maintenance of healed erosive esophagitis (EE); 60  mg is approved for healing EE. The present study assesses the pharmacokinetic (PK) profile and safety of dexlansoprazole MR in adolescent patients.

PATIENTS AND METHODS

Phase 1, open-label, parallel-group, multicenter study in male and female adolescents (12-17 years) with GERD. Patients were randomized to receive dexlansoprazole MR (30 or 60  mg, QD) for 7 days. Blood samples to determine dexlansoprazole plasma concentrations were drawn over a 24-hour period after dosing on day 7. Dexlansoprazole plasma concentrations and PK parameters were summarized by dose group. Safety assessments included monitoring of adverse events (AEs).

RESULTS

Thirty-six patients (mean age 14.6 years), 14 boys and 22 girls, were randomized, with PK data available for 35 patients. The overall exposure of dexlansoprazole after administration of the 60-mg capsule was slightly less than double the exposure from the 30-mg capsule. Cmax (691 and 1136  ng/mL) and area under the plasma concentration time curve (2886 and 5120  ng · h/mL) values for the 30- and 60-mg doses, respectively, were similar to results from previous phase 1 studies in healthy adults. Twelve of 36 patients (33.3%) experienced a total of 21 treatment-emergent AEs. All of the AEs were considered to be of mild severity.

CONCLUSIONS

The PK data for dexlansoprazole MR 30- and 60-mg capsules in adolescent patients with symptomatic GERD were similar to those in healthy adults. Both doses were well tolerated.