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

Pharmacokinetics and Pharmacodynamics of Lansoprazole/Sodium Bicarbonate Immediate-release Capsules in Healthy Chinese Subjects: An Open, Randomized, Controlled, Crossover, Single-, and Multiple-dose Trial

Proton pump inhibitors (PPIs) differ in onset of action and bioavailability. This trial was conducted to investigate the pharmacokinetics and pharmacodynamics of an immediate-release capsule formulation containing lansoprazole 30 mg and sodium bicarbonate 1100 mg (T preparation) in healthy Chinese subjects. This was an open, single-center, randomized, single and multiple oral doses, and two-period crossover study in 30 healthy subjects. After single- and multiple-dose oral administration, blood samples were obtained and lansoprazole concentration in serum was measured for pharmacokinetic analysis. Meanwhile, the intragastric pH was monitored continuously to evaluate the pharmacodynamics of the investigational drugs. The Tmax of the T preparation was 0.5 hours, while the Tmax of the R preparation was 1.5 hours after multiple doses, which indicated that the absorption speed of the T preparation was significantly faster than that of the R preparation. The same characteristics also existed after single-dose administration. The area under the curve (AUC)ss of the T preparation was bio-equivalent to that of the R preparation under steady state. The time percentage of intragastric pH > 4.0 for the T preparation was higher than that of the R preparation after 1 hour for both single- and multiple-dose. It suggested compared with R preparation, the time percentage of intragastric pH > 4.0 met the criteria for superiority after 1 hour administration for the T preparation. In addition, no serious adverse events occurred in this study. Across this study, the T preparation was better than the R preparation at improving drug absorption and increasing intragastric pH, and had a favorable safety profile.

Efficacy of vonoprazan 10 mg compared with 20 mg for the initial treatment in patients with erosive esophagitis: a randomized pilot study

BACKGROUND

The study aimed to investigate the efficacy of vonoprazan 10 mg compared with 20 mg in patients with erosive esophagitis.

METHOD

Seventy-three patients with erosive esophagitis were randomly divided into two groups either vonoprazan 20 mg (n = 37) or 10 mg (n = 36). They were administered each dose for 4 weeks as the initial treatment followed by maintenance treatment with 10 mg for 8 weeks. The primary endpoints were mucosal healing rate and symptom relief at 4 weeks. The secondary endpoint was symptom relief at 12 weeks after the maintenance treatment. Mucosal healing was assessed endoscopically, and symptom relief was assessed using the FSSG score.

RESULTS

At 4 weeks, the endoscopic healing rates of the 20 mg and 10 mg groups were 94.6% and 94.4%, respectively. The FSSG scores of the 20 mg and 10 mg groups were significantly decreased in both treatment groups from 13 (4-39) to 4 (0-25) and 14 (4-40) to 3 (0-29), respectively. At 12 weeks, the scores further decreased to 2 (0-13) and 2 (0-26), respectively. The vonoprazan 10 mg group showed a similar therapeutic effect to the 20 mg group in mucosal healing at 4 weeks and in symptom relief throughout the study period. When stratified by esophagitis grading, these findings were still demonstrated in grade A/B patients but not in grade C/D patients.

CONCLUSION

Our findings suggest that initial treatment with vonoprazan 10 mg might be useful especially in patients with mild erosive esophagitis. Large controlled studies are warranted to confirm our investigation.

Rabeprazole: A comprehensive profile

Rabeprazole belongs to the class of anti-secretory drugs, with benzimidazoles substitution. These drugs induce gastric acid secretion through precise inhibition of the enzyme H⁺/K⁺-ATPase (acid or proton pump). This effect helps to treat and prevent conditions in which gastric acid directly aggravates symptoms such as duodenal and gastric ulcers. This chapter includes a comprehensive review of rabeprazole in terms of nomenclature, its physical-chemical properties, methods of preparation and ADME profiles. In addition, the chapter also includes a review of several methods for analysis of rebeprazole in its dosage forms and biological fluids.

Adverse effects reported in the use of gastroesophageal reflux disease treatments in children: a 10 years literature review

Gastroesophageal reflux (GER) is commonly observed in children, particularly during the first year of life. Pharmacological therapy is mostly reserved for symptomatic infants diagnosed with GER disease (GERD), usually as defined in a recent consensus statement. The purpose of the present article was to review the reported adverse effects of pharmacological agents used in the treatment of paediatric GERD. We conducted this review using the electronic journal database Pubmed and Cochrane database systematic reviews using the latest 10-year period (1 January 2003 to 31 December 2012). Our search strategy included the following keywords: omeprazole, esomeprazole, lansoprazole, pantoprazole, rabeprazole, rantidine, cimetidine, famotidine, nizatidine, domperidone, metoclopramide, betanechol, erythromycin, baclofen, alginate. We used Pubmed's own filter of: 'child: birth-18 years'. All full articles were reviewed and we only included randomized controlled trials retrieved from our search. We addressed a summary of our search on a drug-by-drug basis with regard to its mechanism of action and clinical applications, and reviewed all of the adverse effects reported and the safety profile of each drug. Adverse effects have been reported in at least 23% of patients treated with histamine H2 receptor antagonists (H2 RAs) and 34% of those treated with proton pump inhibitors (PPIs), and mostly include headaches, diarrhoea, nausea (H2 RAs and PPIs) and constipation (PPIs). Acid suppression may place immune-deficient infants and children, or those with indwelling catheters, at risk for the development of lower respiratory tract infections and nosocomial sepsis. Prokinetic agents have many adverse effects, without major benefits to support their routine use.

Pharmacokinetics and tolerability of rabeprazole in children 1 to 11 years old with gastroesophageal reflux disease

BACKGROUND

The pharmacokinetics of rabeprazole after a single oral dose and once-daily administration for 5 consecutive days was characterized in children 1 to 11 years old with gastroesophageal reflux disease (GERD).

PATIENTS AND METHODS

The initial 8 patients received rabeprazole sodium (hereafter referred to as rabeprazole) 0.14 mg/kg (part 1); the next 20 patients were randomized to receive 0.5 or 1 mg/kg (part 2) to target concentrations in plasma expected to be safe and effective. Pharmacokinetic parameters of rabeprazole and the thioether metabolite were calculated using noncompartmental methods. Subjective evaluations of GERD severity, rabeprazole short-term effectiveness, palatability, and safety were also characterized.

RESULTS

Rabeprazole concentrations increased in a dose-dependent manner. Little or no accumulation was observed after repeated administration. The results suggest that formation of the thioether is an important metabolic pathway in young patients, which is consistent with adults. Plasma area under the concentration-time curve values of rabeprazole and the metabolite were poorly correlated with individual age and body weight. Furthermore, oral rabeprazole clearance values (not adjusted for weight) were similar to historical adult data. However, weight-adjusted values were higher for the pediatric patients, and approximately 2 to 3 times the milligram per kilogram dose of rabeprazole in these children was necessary to achieve comparable concentrations in adults. Subjective evaluations demonstrated an improvement of GERD symptoms in most patients after rabeprazole treatment.

CONCLUSIONS

Palatability of the formulation was reported to be good or excellent. Rabeprazole was well tolerated, with no notable differences in safety among the dose groups.

The Influence of CYP2C19 Polymorphism on Eradication of Helicobacter pylori: A Prospective Randomized Study of Lansoprazole and Rabeprazole

BACKGROUND/AIMS

The CYP2C19 polymorphism plays an important role in the metabolism of various proton-pump inhibitors. Several trials have produced conflicting data on eradication rates of Helicobacter pylori (H. pylori) among CYP2C19 genotypes. We investigated whether the CYP2C19 genotype affects the eradication rate of H. pylori by direct comparing the effects of lansoprazole- and rabeprazole-based triple therapies.

METHODS

A total of 492 patients infected with H. pylori was randomly treated with either 30 mg of lansoprazole or 20 mg of rabeprazole plus 500 mg of clarithromycin and 1,000 mg of amoxicillin twice daily for 1 week. CYP2C19 genotype status was determined by a PCR-restriction-fragment-length polymorphism method. After 7 to 8 weeks, H. pylori status was evaluated by a C(13)-urea breath test.

RESULTS

Four hundred and sixty-three patients were analyzed, and the eradication rate was 75.2% in a per-protocol analysis. Eradication rates for the lansoprazole regimen (n=234) were 73.8%, 80.7%, and 85.4% in the homozygous extensive (HomEM), heterozygous extensive (HetEM), and poor metabolizers (PM) groups, respectively (p=0.303). In the case of the rabeprazole regimen (n=229), the eradication rates were 68.6%, 73.0%, and 71.9% in the HomEM, HetEM, and PM groups, respectively (p=0.795).

CONCLUSIONS

The efficacies of triple therapies that include lansoprazole or rabeprazole are not affected by CYP2C19 genetic polymorphisms.

Systematic review: standard- and double-dose proton pump inhibitors for the healing of severe erosive oesophagitis -- a mixed treatment comparison of randomized controlled trials

BACKGROUND

No randomized controlled trial (RCT) has compared all European-licensed standard- and double-dose PPIs for the healing of severe erosive oesophagitis.

AIM

To compare the effectiveness of licensed doses of PPIs for healing severe erosive oesophagitis (i.e. esomeprazole 40 mg, lansoprazole 30 mg, omeprazole 20 mg and 40 mg, pantoprazole 40 mg and rabeprazole 20 mg).

METHODS

Systematic review of CENTRAL, EMBASE and MEDLINE for RCTs in patients with erosive oesophagitis (completed October 2008). Endoscopically verified healing rates at 4 and 8 weeks were extracted and re-calculated if not analysed by intention-to-treat. A mixed treatment comparison was used to combine direct treatment comparisons with indirect trial evidence while maintaining randomization. Odds ratios (OR) are reported compared to omeprazole 20 mg.

RESULTS

A total of 3021 papers were identified in the literature search; 12 were of sufficient quality to be included in the analysis. Insufficient data were available to included rabeprazole. Esomeprazole 40 mg was found to provide significantly higher healing rates at 4 weeks [OR 1.84, 95% Credible Interval (95% CrI): 1.50 to 2.22] and 8 weeks (OR 1.91, 95% CrI: 1.13 to 2.88). No other PPI investigated had significantly higher healing rates than omeprazole 20 mg.

CONCLUSION

Esomeprazole 40 mg consistently demonstrates higher healing rates compared with licensed standard- and double-dose PPIs.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Proton pump inhibitors: an update of their clinical use and pharmacokinetics

BACKGROUND

Proton pump inhibitors (PPIs) represent drugs of first choice for treating peptic ulcer, Helicobacter pylori infection, gastrooesophageal reflux disease, nonsteroidal anti-inflammatory drug (NSAID)-induced gastrointestinal lesions (complications), and Zollinger-Ellison syndrome.

RESULTS

The available agents (omeprazole/esomeprazole, lansoprazole, pantoprazole, and rabeprazole) differ somewhat in their pharmacokinetic properties (e.g., time-/dose-dependent bioavailability, metabolic pattern, interaction potential, genetic variability). For all PPIs, there is a clear relationship between drug exposure (area under the plasma concentration/time curve) and the pharmacodynamic response (inhibition of acid secretion). Furthermore, clinical outcome (e.g., healing and eradication rates) depends on maintaining intragastric pH values above certain threshold levels. Thus, any changes in drug disposition will subsequently be translated directly into clinical efficiency so that extensive metabolizers of CYP2C19 will demonstrate a higher rate of therapeutic nonresponse.

CONCLUSIONS

This update of pharmacokinetic, pharmacodynamic, and clinical data will provide the necessary guide by which to select between the various PPIs that differ-based on pharmacodynamic assessments-in their relative potencies (e.g., higher doses are needed for pantoprazole and lansoprazole compared with rabeprazole). Despite their well-documented clinical efficacy and safety, there is still a certain number of patients who are refractory to treatment with PPIs (nonresponder), which will leave sufficient space for future drug development and clinical research.