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

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

Pharmacokinetics of rabeprazole granules versus tablets, and the effect of food on the pharmacokinetics of rabeprazole granules in healthy adults-cross-study comparison

The primary objective was to compare the pharmacokinetics (PK) of rabeprazole granules versus rabeprazole tablets, and assess the effect of food on the PK of rabeprazole granules. Data from three phase 1, open-label, single-dose, randomized, crossover studies in healthy adult participants are presented separately and as a cross-study comparison; study 1: PK of phase 1 rabeprazole granules versus rabeprazole tablets under fasting conditions; study 2: PK of phase 3 rabeprazole granules versus phase 1 rabeprazole granules; study 3: bioequivalence of to-be-marketed rabeprazole granules (sprinkle capsules) versus phase 3 rabeprazole granules; and assessment of the food effect for the to-be-marketed rabeprazole granules. Overall, 123 of 130 participants enrolled completed the studies. The overall plasma exposure as measured by area under the plasma concentration-time curve (AUC) was comparable between rabeprazole granules and tablets; mean peak plasma concentration (Cmax ) was lower for the granules compared with tablets. The plasma elimination half-life was short and independent of formulation. Food intake prior to administration of the to-be-marketed granules delayed the absorption and reduced the estimated parameters for bioavailability by 55% (Cmax ) and 28% (AUCinf ). Rabeprazole was well-tolerated.

A new esomeprazole packet (sachet) formulation for suspension: in vitro characteristics and comparative pharmacokinetics versus intact capsules/tablets in healthy volunteers

BACKGROUND

A packet (sachet) formulation of esomeprazole for suspension has been developed for use in patients who have difficulty swallowing.

OBJECTIVES

This article reports the in vitro characteristics of the new esomeprazole formulation, including stability in suspension and suitability for administration orally or via enteral tubes. It also describes the pharmacokinetic profile of the esomeprazole 40-mg packet compared with that of existing solid dosage forms (capsules and tablets) in a clinical bioequivalence study.

METHODS

The stability in suspension of the packet formulation was assessed after reconstitution at various strengths (2.5, 10, and 40 mg) and a different pH (3.4-5.0) in strength-appropriate volumes of water held at temperatures ranging from 5 degrees C to 37 degrees C for up to 60 minutes. Suitability for oral administration was examined in terms of reconstitution time and the actual dose delivered after simulated oral administration, as well as in terms of the actual dose delivered by enteral tubes ranging in diameter from 6 to 20 Fr. Chemical stability and suspension characteristics were also analyzed using alternative reconstitution vehicles (applesauce, apple juice, and orange juice). The comparative pharmacokinetics of the packet, capsule, and tablet formulations of esomeprazole were evaluated in a randomized, open-label, 3-way crossover study in healthy volunteers, who received single 40-mg doses of each formulation. Bioequivalence was assumed if the 90% CIs for the ratios of the geometric mean AUC and CmaX were between 0.80 and 1.25. Reversephase liquid chromatography with ultraviolet detection was used to assess the esomeprazole content and/or degradation products of esomeprazole in the tests for in-suspension stability, dose delivery, and acid resistance. Normal-phase liquid chromatography was used to assess the esomeprazole content of the plasma samples in the bioequivalence study.

RESULTS

At the pH and temperature ranges investigated, the packet formulation was stable for up to 60 minutes after reconstitution. Chemical degradation was low (<0.1%) for all reconstitution vehicles investigated. Reconstitution time was 2 minutes with water and 9 to 10 minutes with apple or orange juice. Dose delivery was >/=98% after simulated oral administration and was generally >/=96% after administration via enteral tubes. Ninety-six healthy volunteers (56 women, 40 men; mean age, 24.9 years; mean weight, 68.9 kg) participated in the randomized, crossover, comparative pharmacokinetic study of the packet and capsule/tablet formulations. The estimated ratios of the geometric mean AUC and C(max) for the packet:capsule and packet: tablet formulations were 0.98 (90% CI, 0.93-1.03) and 0.99 (90% CI, 0.94-1.04), respectively.

CONCLUSIONS

In these analyses, the packet (sachet) formulation of esomeprazole was chemically stable in suspension and when administered orally and via enteral tubes. The formulation had a short reconstitution time, remaining fully dispersed in water for at least 30 minutes, and was dispersed in applesauce, apple juice, or orange juice without compromising its stability or dispersion characteristics. The packet formulation met the regulatory definition for bioequivalence to the tablet and capsule formulations.

Efficacy of esomeprazole in patients with acid-peptic disorders

Esomeprazole (Nexium) is a new proton pump inhibitor that provides more effective acid control compared with other proton pump inhibitors. In patients with gastroesophageal reflux disease, standard doses of esomeprazole maintain intragastric pH above 4 for significantly longer periods compared with standard doses of other proton pump inhibitors after 5 days of treatment. Esomeprazole is approved for the treatment of symptomatic gastroesophageal reflux disease, the healing of erosive esophagitis, and maintenance of healing. In clinical trials, esomeprazole 40 mg once daily for up to 8 weeks provided higher rates of healing of erosive esophagitis and a greater proportion of patients with sustained resolution of heartburn, than either omeprazole 20 mg or lansoprazole 30 mg once daily. For the maintenance of healing, esomeprazole 20 mg once daily provided significantly higher rates of maintained healing of erosive esophagitis after 6 months of treatment compared with lansoprazole 15 mg once daily. Esomeprazole is also approved for use as part of a triple-drug therapy regimen in combination with amoxicillin and clarithromycin for the eradication of Helicobacter pylori in patients with duodenal ulcer disease. The side effect profile of esomeprazole is similar to that of omeprazole. Many patients with acid-related disorders may benefit from the more rapid symptom relief, higher rates of healing of erosive esophagitis, and improved maintenance of healing that can be achieved with esomeprazole.

Oral esomeprazole vs. intravenous pantoprazole: a comparison of the effect on intragastric pH in healthy subjects

BACKGROUND

Intravenous (IV) proton-pump inhibitor therapy is used in patients who cannot take oral medications or require greater acid suppression. Oral esomeprazole produces greater acid suppression than oral pantoprazole; however, no comparative data exist for oral esomeprazole and i.v. pantoprazole.

AIM

To compare acid suppression (time with pH>3.0, 4.0, 5.0 and 6.0) produced by standard doses of oral esomeprazole and i.v. pantoprazole in healthy subjects.

METHODS

A randomized, two-way crossover study in 30 subjects receiving oral esomeprazole (40 mg o.d.) or i.v. pantoprazole (40 mg o.d.) for 5 days followed by a 2-week washout period before the second 5-day drug administration period using the crossover drug regimen.

RESULTS

Oral esomeprazole produced greater acid suppression than i.v. pantoprazole on day 1 [pH>3.0 (56.9%, 35.8%; P<0.001), pH>4.0 (43.4%, 25.0%; P<0.001) and pH>5.0 (28.7%, 15.6%; P<0.001)] and on day 5 [pH>3.0 (70.4%, 45.9%; P<0.001), pH>4.0 (59.2%, 33.9%; P<0.001), pH>5.0 (45.5%, 23.9%; P<0.001) and pH>6.0 (19.6%, 12.6%; P=0.045)]. The adverse event profiles indicated both treatments to be safe and well tolerated.

CONCLUSIONS

In healthy subjects, esomeprazole, 40 mg o.d. dispersed in water, produces greater acid suppression than pantoprazole 40 mg i.v. o.d. after 1 and 5 days of medication.

Esomeprazole administered through a nasogastric tube provides bioavailability similar to oral dosing

AIM

To determine if nasogastric tube administration of the enteric-coated pellets from an opened esomeprazole capsule provides bioavailability similar to oral dosing with the intact capsule.

METHODS

A randomized, single-centre, open-label, two-period crossover pharmacokinetic study consisting of two 5-day dosing periods separated by a 7- to 14-day washout period was conducted. Healthy subjects between the ages of 18 and 50 years received esomeprazole 40 mg once daily either orally as an intact capsule, or as a suspension of the enteric-coated pellets from an opened capsule in water through a nasogastric tube.

RESULTS

In 47 evaluable subjects, the 90% confidence intervals were 0.87-1.08 and 0.93-1.25 for the geometric mean of the ratio of nasogastric tube administration relative to administration of the intact capsule for the area under the plasma concentration-time curve and for maximum plasma concentration, respectively, on day 1, demonstrating bioequivalence. Oral and nasogastric administration also demonstrated similar bioavailabilities on day 5. Esomeprazole was well tolerated regardless of the mode of administration.

CONCLUSIONS

Nasogastric tube administration of the enteric-coated pellets from an opened esomeprazole 40 mg capsule provides bioavailability similar to oral dosing. Administration of the contents of an opened esomeprazole 40 mg capsule in water through a nasogastric tube is a practical alternative for patients with feeding tubes who require effective gastric acid suppression, but cannot swallow an oral preparation.

Treatment of acid-related diseases in the elderly with emphasis on the use of proton pump inhibitors

Proton pump inhibitors (PPIs) have revolutionised the treatment of acid-related disorders, and they have also made it possible to define the spectrum of acid inhibition required for optimal treatment in each disorder. Five PPIs are now available: the older drugs, omeprazole, lansoprazole and pantoprazole, and the two newest, rabeprazole and esomeprazole. These agents have predominantly been developed in the younger adult population, and data for the elderly population are limited. Subtle differences have emerged between the old and the new PPIs in their pharmacokinetic, pharmacodynamic and efficacy profiles. The degree of clinical relevance of these differences in the adult population is in question. However, according to this review, based on the available data for the elderly and by inference from the adult population, the differences are highly relevant in the elderly population. Studies of the pharmacokinetics of older PPIs demonstrated considerable variation in drug clearance that was reflected in a wide range of efficacy related to acid suppression with standard dosages. The newer PPIs offer several advantages over older agents, particularly in terms of rapid, profound and consistent acid inhibition. Consistent acid inhibition is particularly important in the elderly since clinical response is often difficult to judge in this patient group. An individual's cytochrome P450 (CYP) 2C19 genotype predicts the degree of acid suppression and consequently the clinical efficacy of the PPIs. The older PPIs are predominantly metabolised by CYP2C19, with this being of more importance for omeprazole and lansoprazole than pantoprazole. The hepatic metabolism of rabeprazole is predominantly by nonenzymatic reactions and minimally by CYP-mediated reactions, which therefore confers an advantage over older PPIs in that genetic polymorphisms for CYP2C19 do not significantly influence rabeprazole clearance, clinical efficacy or potential for drug interactions. The metabolism of esomeprazole involves CYP2C19 but to a lesser extent than its predecessor omeprazole. Furthermore, esomeprazole has a more rapid onset of action and less variation in clearance rates than omeprazole. Drug clearance decreases with age independently of CYP2C19 status, exaggerating some of the differences between the PPIs and increasing the risk of drug interactions.

Stability of esomeprazole capsule contents after in vitro suspension in common soft foods and beverages

STUDY OBJECTIVE

To determine the in vitro stability of esomeprazole pellets from an opened capsule after suspension in various common soft foods and beverages.

DESIGN

In vitro study.

SETTING

Pharmaceutical company research laboratory.

MEASUREMENTS AND MAIN RESULTS

Pellets from opened esomeprazole 20-mg capsules were suspended in 100 ml of tap water, milk (1.5% fat), orange juice, apple juice, yogurt, or cultured milk for 30 minutes, then added to 500 ml of hydrochloric acid to simulate gastric acid exposure. After a 2-hour incubation, the mixture was filtered through a sieve, and the collected pellets were dissolved in an alkaline solution. Esomeprazole concentrations were measured using reverse-phase liquid chromatography The stability of the esomeprazole pellets exceeded 98% in all beverages and soft foods except milk.

CONCLUSION

Administration of the pellets from an opened esomeprazole capsule shortly after suspending them in tap water, yogurt, cultured milk, orange juice, or apple juice may be a practical alternative for patients who cannot swallow an intact capsule. Bioavailability studies comparing esomeprazole administered as an intact capsule to that of the pellets from an opened capsule suspended in these beverages or soft foods are recommended to confirm these findings.

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.

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

Esomeprazole (S-isomer of omeprazole), the first single optical isomer proton pump inhibitor, generally provides better acid control than current racemic proton pump inhibitors and has a favourable pharmacokinetic profile relative to omeprazole. In a large well designed 8-week trial in patients (n >5000) with erosive oesophagitis, esomeprazole recipients achieved significantly higher rates of endoscopically confirmed healed oesophagitis than those receiving lansoprazole. Respective healed oesophagitis rates with once-daily esomeprazole 40mg or lansoprazole 30mg were 92.6 and 88.8%. Overall, esomeprazole was also better than omeprazole, although these differences were not always statistically significance. Ninety-two to 94% of esomeprazole recipients (40mg once daily) achieved healed oesophagitis versus 84 to 90% of omeprazole recipients (20mg once daily). Esomeprazole was effective across all baseline grades of oesophagitis; notably, relative to lansoprazole, as baseline severity of disease increased, the difference in rates of healed oesophagitis also increased in favour of esomeprazole. Resolution of heartburn was also significantly better with esomeprazole 40mg than with these racemic proton pump inhibitors. Long-term (up to 12 months) therapy with esomeprazole effectively maintained healing in these patients. Once-daily esomeprazole 20 or 40mg for 4 weeks resolved symptoms in patients with symptomatic gastro-oesophageal reflux disease (GORD) without oesophagitis. Symptoms were effectively managed in the long-term with symptom-driven on-demand esomeprazole (20 or 40mg once daily). Eradicating Helicobacter pylori infection is considered pivotal to successfully managing duodenal ulcer disease. Seven days' treatment (twice-daily esomeprazole 20mg plus amoxicillin 1g and clarithromycin 500mg) eradicated H. pylori in >/=86% of patients (intention-to-treat), a rate that was similar to equivalent omeprazole-based regimens. Esomeprazole is generally well tolerated, both as monotherapy and in combination with antimicrobial agents, with a tolerability profile similar to that of other proton pump inhibitors. Few patients discontinued therapy because of treatment-emergent adverse events (<3% of patients), with very few (<1%) drug-related serious adverse events reported.

CONCLUSIONS

Esomeprazole is an effective, well tolerated treatment for managing GORD and for eradicating H. pylori infection in patients with duodenal ulcer disease. In 8-week double-blind trials, esomeprazole healed oesophagitis and resolved symptoms in patients with endoscopically confirmed erosive oesophagitis and overall, provided better efficacy than omeprazole. Notably, in a large (n >5000 patients) double-blind trial, esomeprazole 40mg provided significantly better efficacy than lansoprazole in terms of healing rates and resolution of symptoms. Long-term therapy with esomeprazole maintained healed oesophagitis in these patients. Esomeprazole also proved beneficial in patients with symptomatic GORD without oesophagitis. Thus, esomeprazole has emerged as an option for first-line therapy in the management of acid-related disorders.

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

Esomeprazole, the S-isomer of omeprazole, is the first proton pump inhibitor to be developed as a single optical isomer. It provides better acid control than current racemic proton pump inhibitors and has a favourable pharmacokinetic profile relative to omeprazole. In large well designed 8-week trials in patients with erosive oesophagitis, esomeprazole recipients achieved significantly higher rates of endoscopically confirmed healed oesophagitis than those receiving omeprazole or lansoprazole. Esomeprazole was effective across all baseline grades of oesophagitis; notably, relative to lansoprazole, as the baseline severity of disease increased, the difference in rates of healed oesophagitis also increased in favour of esomeprazole. In two trials, 94% of patients receiving esomeprazole 40mg once daily achieved healed oesophagitis versus 84 to 87% of omeprazole recipients (20mg once daily). In a study in >5000 patients, respective healed oesophagitis rates with once-daily esomeprazole 40mg or lansoprazole 30mg were 92.6 and 88.8%. Resolution of heartburn was also significantly better with esomeprazole than with these racemic proton pump inhibitors. Long-term (up to 12 months) therapy with esomeprazole effectively maintained healed oesophagitis in these patients. Esomeprazole 20 or 40mg once daily for 4 weeks proved effective in patients with symptomatic gastro-oesophageal reflux disease (GORD) without oesophagitis. Eradicating Helicobacter pylori infection is considered pivotal to successfully managing duodenal ulcer disease. Ten days' triple therapy (esomeprazole 40mg once daily, plus twice-daily amoxicillin 1g and clarithromycin 500mg) eradicated H. pylori in 77 to 78% of patients (intention-to-treat) with endoscopically confirmed duodenal ulcer disease. Esomeprazole is generally well tolerated, both as monotherapy and in combination with antimicrobial agents. The tolerability profile is similar to that of other proton pump inhibitors. Few patients discontinued therapy because of treatment-emergent adverse events (<3% of patients) and very few (<1%) drug-related serious adverse events were reported.

CONCLUSIONS

Esomeprazole is an effective and well tolerated treatment for managing GORD and for eradicating H. pylori infection in patients with duodenal ulcer disease. In 8-week double-blind trials, esomeprazole effectively healed oesophagitis and resolved symptoms in patients with endoscopically confirmed erosive oesophagitis. Notably, in large (n >1900 patients) double-blind trials, esomeprazole provided significantly better efficacy than omeprazole or lansoprazole in terms of both healing rates and resolution of symptoms. Long-term therapy with esomeprazole effectively maintained healed oesophagitis in these patients. Esomeprazole was also effective in patients with symptomatic GORD. Thus, esomeprazole has emerged as an effective option for first-line therapy in the management of acid-related disorders.