Esomeprazole: a review of its use in the management of acid-related disorders in the US

Pharmacokinetics and pharmacodynamics of intravenous esomeprazole at 2 different dosages in dogs

Background

Although the demand for esomeprazole is increasing in veterinary medicine, the pharmacokinetics (PK) and pharmacodynamics of esomeprazole have been described in only a few studies.

Objective

To determine the PK of 0.5 and 1 mg/kg esomeprazole administered IV q12h and to investigate its effects on intragastric pH in healthy dogs.

Animals

Six adult Beagles.

Methods

Open‐label, randomized, and crossover design. The dogs received 0.5 or 1 mg/kg esomeprazole IV q12h for 48 hours. Plasma concentrations of esomeprazole were measured by high‐performance liquid chromatography‐tandem mass spectrometry. Intragastric pH was determined using the Bravo pH monitoring system and recorded as mean percentage time (MPT) for which pH was ≥3 and ≥4 for 24 hours in each group.

Results

The peak plasma concentration and area under the curve from the time of dosing to the last measurable concentration in the 1 mg/kg group were higher than those in the 0.5 mg/kg group. However, when the dosage normalized, intergroup differences were not significant. The MPTs for which intragastric pH was ≥3 and ≥4 for 48 hours were 88% ± 7% and 81% ± 9% for the 0.5 mg/kg group and 90% ± 9% and 85% ± 11% for the 1 mg/kg group, respectively, with no significant intergroup differences.

Conclusions and Clinical Importance

The pharmacokinetic parameters and acid suppressant effect for 0.5 and 1 mg/kg esomeprazole were not significantly different. Furthermore, the efficacy of esomeprazole 0.5 mg/kg IV q12h was sufficient to increase intragastric pH in Beagles.

Pharmacokinetics and Acid Suppressant Efficacy of Esomeprazole after Intravenous, Oral, and Subcutaneous Administration to Healthy Beagle Dogs

Background

Esomeprazole is an S‐enantiomer of omeprazole that has favorable pharmacokinetics and efficacious acid suppressant properties in humans. However, the pharmacokinetics and effects on intragastric pH of esomeprazole in dogs have not been reported.

Objective

To determine the pharmacokinetics of esomeprazole administered via various routes (PK study) and to investigate the effect of esomeprazole on intragastric pH with a Bravo pH monitoring system (PD study).

Animals

Seven adult male Beagle dogs and 5 adult male Beagle dogs were used for PK and PD study, respectively.

Methods

Both studies used an open, randomized, and crossover design. In the PK study, 7 dogs received intravenous (IV), subcutaneous (SC), and oral doses (PO) of esomeprazole (1 mg/kg). Each treatment period was separated by a washout period of at least 10 days. Esomeprazole plasma concentrations were measured by HPLC/MS/MS. In the efficacy study, intragastric pH was recorded without medication (baseline pH) and following IV, SC, and PO esomeprazole dosing regimens (1 mg/kg) in 5 dogs.

Results

The bioavailability of esomeprazole administered as PO enteric‐coated granules and as SC injections was 71.4 and 106%, respectively. The half‐life was approximately 1 hour. Mean ± SD percent time intragastric pH was ≥3 and ≥4 was 58.9 ± 21.1% and 40.9 ± 17.3% for IV group, 75.8 ± 16.4% and 62.7 ± 17.7% for SC group, 88.2 ± 8.9% and 82.5 ± 7.7% for PO group, and 12.5 ± 3.6% and 3.7 ± 1.8% for baseline. The mean percent time with intragastric pH was ≥3 or ≥4 was significantly increased regardless of the dosing route (P < .05).

Conclusion

The PK parameters for PO and SC esomeprazole administration were favorable, and esomeprazole significantly increased intragastric pH after IV, PO, and SC administration. IV and SC administration of esomeprazole might be useful when PO administration is not possible. No significant adverse effects were observed.

Development and validation of a high throughput UPLC-MS/MS method for simultaneous quantification of esomeprazole, rabeprazole and levosulpiride in human plasma

A high throughput ultra pressure liquid chromatography–mass spectrometry (UPLC–MS/MS) method with good sensitivity and selectivity has been developed and validated for simultaneous quantification of esomeprazole, rabeprazole and levosulpiride in human plasma using lansoprazole as internal standard (IS). The extraction method based on liquid–liquid extraction technique was used to extract the analytes and IS from of 50 µL of human plasma using methyl tert-butyl ether:ethyl acetate (80:20, v/v), which offers a high recovery. Chromatographic separation of analytes and IS was achieved on a Hypersil gold C₁₈ column using gradient mobile phase consisting of 2 mM ammonium formate/acetonitrile. The flow rate was set at 0.5 mL/min to elute all the analytes and IS within 1.00 min runtime. Detection of target compounds was performed on a triple quadruple mass spectrometer by multiple reaction monitoring (MRM) mode via positive electrospray ionization (ESI). Method validation results demonstrated that the developed method has good precision and accuracy over the concentration ranges of 0.1–2000 ng/mL for each analyte. Stability of compounds was established in a battery of stability studies, i.e., bench top, autosampler, dry extract and long-term storage stability as well as freeze-thaw cycles. The validated method has been successfully applied to analyze human plasma samples for application in pharmacokinetic studies.

Proton pump inhibitor-related headaches: A nationwide population-based case-crossover study in Taiwan

Background

Headaches resulting from proton pump inhibitor (PPI) use could cause discontinuation of PPI in as many as 40% of patients who experience such headaches. Previous studies focusing on acute headache risk from PPI use are rare and limited to clinical trials of a single PPI.

Objectives

To investigate the association between PPI use and headache with a nationwide population-based case-crossover study.

Methods

Records containing the first diagnosis of any headache, including migraine and tension-type headaches, were retrieved from Taiwan National Health Insurance Database (1998–2010). We compared the rates of PPI use for cases and controls during time windows of 7, 14, and 28 days. The adjusted self-matched odds ratios (ORs) and 95% confidence intervals (CIs) from a conditional logistic regression model were used to determine the association between PPI use and headache.

Results

Overall, 314,210 patients with an initial diagnosis of any headache during the study period were enrolled. The adjusted ORs for headache risk after PPI exposure were calculated for three time periods (within 7 days = 1.41, p = 0.002, 95% CI 1.14–1.74; within 14 days = 1.36, p < 0.001, 95% CI 1.16–1.59; within 28 days = 1.20, p = 0.002, 95% CI 1.07–1.35). Subgroup analyses showed female patients had an increased risk of headache. Among PPIs, lansoprazole and esomeprazole had the highest risks of headache incidence, which were similar to that of nitrates.

Conclusion

PPI usage is associated with an increased risk for acute headache. Female patients and use of lansoprazole or esomeprazole present the greatest risks of headache.

High-dose versus low-dose esomeprazole-based triple therapy for Helicobacter pylori infection

BACKGROUND

This prospective, randomized, controlled study was conducted to compare the efficacies of high-dose and low-dose esomeprazole-based triple therapies for Helicobacter pylori eradication in Taiwan.

MATERIALS AND METHODS

From January 2004 to June 2006, 240 H. pylori-infected patients were randomly assigned to undergo high-dose (40 mg b.d.) or low-dose (40 mg o.d.) esomeprazole combined with clarithromycin (500 mg b.d.) and amoxicillin (1 g b.d.) for one week. Follow-up endoscopy was performed at eight weeks after the end of treatment to evaluate the response to therapy.

RESULTS

Intention-to-treat analysis demonstrated no differences between eradication rates of high-dose and low-dose groups (92% vs. 90%, respectively, P > 0.05). Per-protocol analysis yielded comparable results (95% vs. 93%). Both groups exhibited similar frequencies of adverse events (13% vs. 11%) and drug compliance (96% vs. 93%). Multivariate analysis indicated that only good compliance (odds ratio: 10.3, 95% CI, 3.0-35.7) was an independent predictor of treatment success.

CONCLUSIONS

This work demonstrates that low-dose esomeprazole-based triple therapy yields a similar eradication rate as high-dose esomeprazole-based therapy in Taiwan. Since the cost of the low-dose regime is lower than that of the high-dose regime, low-dose esomeprazole-based triple therapy can reasonably be recommended for the first-line eradication of H. pylori for Taiwanese and probably most Asians.

Sensitive quantification of omeprazole and its metabolites in human plasma by liquid chromatography–mass spectrometry

A sensitive method was developed for the simultaneous determination of omeprazole and its major metabolites 5-hydroxyomeprazole and omeprazole sulfone in human plasma by HPLC-electrospray mass spectrometry. Following liquid-liquid extraction HPLC separation was achieved on a ProntoSil AQ, C18 column using a gradient with 10 mM ammonium acetate in water (pH 7.25) and acetonitrile. The mass spectrometer was operated in the selected ion monitoring mode using the respective MH(+) ions, m/z 346 for omeprazole, m/z 362 for 5-hydroxy-omeprazole and omeprazol-sulfone and m/z 300 for the internal standard (2-{[(3,5-dimethylpyridine-2-yl)methyl]thio}-1H-benzimidazole-5-yl)methanol. The limit of quantification (LOQ) achieved with this method was 5 ng/ml for 5-hydroxyomeprazole and 10 ng/ml for omeprazole and omeprazole-sulfone using 0.25 ml of plasma. Intra- and inter-assay variability was below 11% over the whole concentration range from 5 to 250 ng/ml for 5-hydroxyomeprazol and from 10 to 750 ng/ml for omeprazole and omeprazole-sulfone. The method was successfully applied to the determination of pharmacokinetic parameters of esomeprazole and the two major metabolites after a single dose and under steady state conditions.

A prospective randomized trial of esomeprazole- versus pantoprazole-based triple therapy for Helicobacter pylori eradication

OBJECTIVE

This prospective, randomized, controlled, head-to-head study was conducted to compare the efficacies of esomeprazole- and pantoprazole-based triple therapies for Helicobacter pylori eradication.

METHODS

From January 2002 to October 2003, 200 H. pylori-infected patients were randomly assigned to undergo twice daily treatment with esomeprazole 40 mg (n = 100) or pantoprazole 40 mg (n = 100) combined with clarithromycin 500 mg and amoxicillin 1 g for 1 wk (ECA and PCA groups, respectively). Follow-up endoscopy was performed at 8 wks after the end of treatment to assess the treatment response.

RESULTS

Intention-to-treat analysis demonstrated a significantly higher eradication rate for the ECA group than for the PCA group (94%vs 82%, respectively, p= 0.009). Per-protocol analysis also showed similar results (97%vs 84%, p= 0.003). Both groups had similar frequencies of adverse events (15%vs 24%) and drug compliance (97%vs 96%). Multivariate analysis disclosed that the use of esomeprazole (OR: 1.56, 95% CI, 1.11-2.19) and good compliance 7.39 (95% CI, 1.27-42.95) were independent predictors of treatment success. Alcohol drinking was an independent predictor of eradication failure (OR: 0.18; 95% CI, 0.06-0.54).

CONCLUSION

Esomeprazole-based triple therapy demonstrated a higher eradication rate than pantoprazole-based regimen. The differences in eradiation efficacies between the two study groups may be related to the more powerful acid inhibition effect and stronger anti-H. pylori activity of esomeprazole compared to pantoprazole.

Effect of esomeprazole on nighttime heartburn and sleep quality in patients with GERD: a randomized, placebo-controlled trial

OBJECTIVES

Sleep disturbances are common in patients with gastroesophageal reflux disease (GERD). This study examined the effects of esomeprazole on nighttime heartburn, GERD-related sleep disturbances, sleep quality, work productivity, and regular activities.

METHODS

This multicenter, randomized, double-blind, placebo-controlled trial included adults with GERD-associated sleep disturbances and moderate-to-severe nighttime heartburn (recorded by patient diary during screening). Patients received oral esomeprazole 40 mg (n = 220) or 20 mg (n = 226) or placebo (n = 229) once daily for 4 wk. The primary outcome was relief of nighttime heartburn. Secondary outcomes included resolution of sleep disturbances, sleep quality measured by the Pittsburgh Sleep Quality Index (PSQI) questionnaire, and work productivity measured by the Work Productivity and Activity Impairment Questionnaire.

RESULTS

Nighttime heartburn was relieved in 53.1% (111/209), 50.5% (111/220), and 12.7% (28/221) of patients who received esomeprazole 40 mg, esomeprazole 20 mg, and placebo, respectively. Differences (95% CI) versus placebo were 40.5% (32.4%, 48.5%) and 37.8% (29.9%, 45.7%) and were highly significant (p < 0.0001). GERD-related sleep disturbances resolved in significantly more (p < 0.0001) patients who received esomeprazole 40 (73.7%) or 20 mg (73.2%) than in those who received placebo (41.2%). Both esomeprazole groups had greater PSQI global score changes from baseline (p < 0.0001 vs placebo) and more (p < 0.0001 vs placebo) work hours saved per week per patient compared with baseline (esomeprazole 40 mg, 11.6 h; esomeprazole 20 mg, 12.3 h; placebo, 6.2 h).

CONCLUSIONS

Esomeprazole reduced nighttime heartburn and GERD-related sleep disturbances and improved sleep quality and work productivity.

Intravenous esomeprazole

The proton pump inhibitor esomeprazole comprises the S-isomer of omeprazole. An intravenous formulation of the drug has been developed for use in patients not able to take oral drugs. The level of gastric acid control was similar with intravenous and oral esomeprazole in two studies in healthy volunteers receiving 20 or 40 mg once daily for 5 days. In addition, a similar level of gastric acid control occurred with intravenous esomeprazole 40 mg administered by infusion or injection once daily for 10 days. In healthy volunteers, intravenous esomeprazole provided faster and more effective gastric acid control than intravenous pantoprazole (40 mg once daily for 5 days). In addition, control of basal and pentagastrin-stimulated gastric acid secretion was better with intravenous esomeprazole 40 mg than with intravenous omeprazole 40 mg (single-dose study). Healing rates at 4 weeks were approximate, equals 80% in a well designed study in patients with erosive oesophagitis (n = 246) who received esomeprazole 40 mg once daily intravenously (by injection or infusion) or orally. Intravenous therapy was administered for the first week, after which all patients received oral esomeprazole. Intravenous esomeprazole was generally well tolerated in patients with erosive oesophagitis, with a tolerability profile similar to that of the oral formulation.

Review of esomeprazole in the treatment of acid disorders

Esomeprazole (Nexium, AstraZeneca) is the (S)-isomer of omeprazole and the first proton pump inhibitor to be developed as an optical isomer. Esomeprazole has an improved pharmacokinetic profile, resulting in increased systemic exposure and less interindividual variability compared with omeprazole, and more effective suppression of gastric acid production compared with other proton pump inhibitors. In several large, double-blind, randomised trials, significantly higher rates of endoscopically-confirmed healing of erosive oesophagitis and resolution of heartburn have been achieved in patients with gastro-oesophageal reflux disease receiving 8 weeks of esomeprazole 40 mg o.d. compared with those receiving omeprazole 20 mg o.d. or lansoprazole 30 mg o.d. In the maintenance of healed erosive oesophagitis, esomeprazole 10, 20 or 40 mg o.d. was significantly more effective than placebo in two 6-month, randomised, double-blind trials. Additionally, esomeprazole 20 mg o.d. was more effective than lansoprazole 15 mg in the maintenance of healed erosive oesophagitis in another 6-month, randomised, double-blind trial. Healing of oesophagitis was also effectively maintained by esomeprazole 40 mg o.d. in a 12-month non-comparative trial. Esomeprazole 20 or 40 mg o.d. effectively relieved heartburn in patients with gastro-oesophageal reflux disease without oesophagitis in two 4-week, placebo-controlled trials. Clinical trials have shown that triple therapy with esomeprazole 40 mg o.d. in combination with amoxicillin and clarithromycin produced Helicobacter pylori eradication rates similar to those obtained using triple therapy involving twice-daily dosing with other proton pump inhibitors. Esomeprazole is well-tolerated, with a spectrum and incidence of adverse events similar to those associated with omeprazole.

New strategies for the prevention and treatment of Helicobacter pylori infection

Helicobacter pylori infects the stomach of > 50% of the human population worldwide, with higher prevalence in the developing countries. A strict correlation between H. pylori infection and gastroduodenal diseases has been demonstrated, including gastritis, peptic ulcer and gastric cancer. Current therapies against H. pylori consist of an antisecretory plus antibiotics. These therapies are effective in 80 - 90% of the cases; presently, no alternative therapies have been shown to give comparable or better results. There are two main reasons for therapy failure: poor compliance, which results in cure discontinuation, and antibiotic resistance. To overcome the drawbacks inherent to any antibiotic therapy, a prophylactic vaccine seems to be the most reasonable approach. Vaccines have been developed based on data obtained in animal models, a number of which are currently in Phase I clinical trials, in some cases giving encouraging data for safety and immunogenicity. In the absence of any immunological correlate of protection against H. pylori, it will be possible to evaluate the efficacy of these vaccines only in large Phase III clinical trials.