Intragastric acidity after switching from 5-day treatment with intravenous pantoprazole 40 mg/d to 5-day treatment with oral esomeprazole 40 mg/d or pantoprazole 40 mg/d: an open-label crossover study in healthy adult volunteers

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.

A novel K+ competitive acid blocker, YH4808, sustains inhibition of gastric acid secretion with a faster onset than esomeprazole: randomised clinical study in healthy volunteers

BACKGROUND

YH4808, a K⁺ -competitive acid blocker, is under clinical development for the treatment of acid-related disorders, such as gastroesophageal reflux disease.

AIMS

To determine the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of YH4808, compared to placebo and esomeprazole.

METHODS

This double-blind, randomised, placebo- and active comparator (esomeprazole)-controlled study was conducted with 123 healthy male volunteers. We evaluated YH4808 (30-800 mg) properties, administered in single (N=55) and multiple (N=24) oral doses, and recorded the effects on 24-hour intragastric acidity. Results were compared to placebo (N=20) and esomeprazole 40 mg (N=24).

RESULTS

Plasma YH4808 exposure increased dose-proportionally and declined in a multi-phasic manner. YH4808 ≥200 mg/d maintained intragastric acidity at pH >4 for longer times than esomeprazole during both day and night (%Time at pH >4: >70% vs 58% of a 24-hour period, respectively; and >50% vs 33% of a 9-hour night respectively). A twice-daily regimen of YH4808 more effectively controlled intragastric pH at night than a once-daily regimen. In evaluating the mean areas under the intragastric pH-time curves in 15-minute intervals for 2 hours after dosing, we found that YH4808 had a faster onset than esomeprazole. Moreover, unlike esomeprazole, YH4808 PK and PD were not significantly affected by the CYP2C19 genotype of the subjects. YH4808 was well-tolerated at all doses administered.

CONCLUSION

This study showed that YH4808 produced a rapid, sustained suppression of gastric secretion with good tolerability. The results at YH4808 ≥200 mg/d provide a rationale for further clinical investigations in populations with acid-related diseases.

Comparator pH study to evaluate the single-dose pharmacodynamics of dual delayed-release dexlansoprazole 60 mg and delayed-release esomeprazole 40 mg

Background:

This paper describes a Phase 1, single-center, randomized, open-label, two-period crossover study which compared the pharmacodynamic effects of single doses of dexlansoprazole modified-release 60 mg and esomeprazole 40 mg on 24-hour intragastric pH in healthy adult subjects.

Methods:

Forty-four subjects aged 20–54 years were randomized in a 1:1 ratio to two sequence groups defining the order in which they received dexlansoprazole and esomeprazole in periods 1 and 2. Primary pharmacodynamic end points over 24 hours postdose were percentage of time with intragastric pH > 4 and mean pH, and secondary pharmacodynamic end points were percentage of time intragastric pH > 4, and mean pH at 0–12 hours, and at >12–24 hours postdose. Each drug was given after an overnight fast and one hour before breakfast. Continuous pH recording began immediately before dosing through to 24 hours postdose.

Results:

At 0–24 hours postdose, the mean percentage of time with pH > 4 for dexlansoprazole and esomeprazole was 58% and 48%, respectively; the difference was statistically significant (P = 0.003). The average of mean pH values at 0–24 hours postdose for dexlansoprazole and esomeprazole were 4.3 and 3.7, respectively; the difference was statistically significant (P < 0.001). At >12–24 hours postdose, mean percentage of time with pH > 4 and average of mean pH were greater for dexlansoprazole (60% and 4.5, respectively) compared with esomeprazole (42% and 3.5, respectively); the difference was statistically significant (P < 0.001 for both intervals). At 0–12 hours postdose, the difference in dexlansoprazole and esomeprazole values for the pharmacodynamic end points was not statistically significant.

Conclusion:

For the entire 24-hour postdose period, predominantly resulting from the >12–24-hour postdose interval, the average intragastric pH following a single dose of dexlansoprazole 60 mg was higher compared with that observed following a single dose of esomeprazole 40 mg, and the difference was statistically significant.

Esomeprazole for the treatment of peptic ulcer bleeding

Peptic ulcer bleeding is the most common cause of acute bleeding in the upper GI tract. The incidence of peptic ulcer bleeding has slowly decreased and endoscopic treatment options have improved; nevertheless, it remains a very common condition with a 7-15% mortality. Acidic environments have a negative effect on hemostasis. Therefore, acid inhibitors have been applied in the adjuvant treatment of peptic ulcer bleeding, both in preventing rebleeding and in treating the underlying cause. This requires profound acid suppressive therapy aiming for a rapid onset of effect and a persistent intragastric pH above 6. This can only be achieved by proton pump inhibitors (PPIs). Esomeprazole is the S-isomer of omeprazole, and the first PPI to consist of only the active isomer. A number of studies have compared esomeprazole with other PPIs, demonstrating a faster and more persistent increase in intragastric pH with the use of esomeprazole than with other agents. Continuous high-dose intravenous treatment with esomeprazole decreases rebleeding, surgery, transfusion rates and hospital days in peptic ulcer bleeding.

Acid control cannot be improved with a modified-release formulation of a proton pump inhibitor compared with twice-daily dosing of the conventional formulation

AIM

The aim of this study was to compare acid control with a once-daily (od) modified-release (MR) formulation of esomeprazole vs. the conventional formulation (CF) dosed twice-daily (bid).

METHODS

In a randomized, five-way crossover study, 55 healthy volunteers underwent 24-h intragastric pH monitoring after 5-day treatment with MR esomeprazole (40, 60 or 80 mg od) and CF esomeprazole (20 or 40 mg bid).

RESULTS

Modified-release 60 and 80 mg od resulted in a significantly longer time with intragastric pH > 4 than MR 40 mg od (77.1 and 79.0% vs. 66.4%, respectively; both p < 0.05). At equivalent total daily doses, CF 20 mg bid led to a significantly longer time with intragastric pH > 4 than MR 40 mg od (72.3 vs. 66.4%; p < 0.05), and CF 40 mg bid led to a significantly longer time with pH > 4 than MR 80 mg od (85.5 vs. 79.0%; p < 0.05).

CONCLUSIONS

At equivalent total daily doses, the MR formulation of esomeprazole provides less 24-h acid control than the conventional formulation dosed twice-daily.

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.

Effect of increasing esomeprazole and pantoprazole doses on acid control in patients with symptoms of gastro-oesophageal reflux disease: a randomized, dose-response study

BACKGROUND AND OBJECTIVE

In patients with gastro-oesophageal reflux disease (GORD), dose escalation or drug switching may be considered in those with symptoms that persist despite standard-dose proton pump inhibitor (PPI) therapy. This study set out to assess whether increasing the dosage of oral esomeprazole and pantoprazole improves acid control in GORD patients, and to compare the pharmacodynamic efficacy of esomeprazole and pantoprazole administered at different dosages.

METHODS

This was an open-label, randomized, six-way crossover study that included Helicobacter pylori-negative GORD patients (aged 20-60 years) with <30% of time with intragastric pH>4. Patients were treated with oral once-daily esomeprazole 20 mg, 40 mg and 80 mg, and pantoprazole 20 mg, 40 mg and 80 mg, for 5 days. The main outcome measures were time with intragastric pH>4 over 24 hours, median pH over 24 hours and area under the hydrogen ion versus time curve on day 5 for each treatment period.

RESULTS

Dose escalation with both PPIs improved acid control. The proportion of time with intragastric pH>4 (day 5) was 46.7% with esomeprazole 20 mg/day, 58.6% with esomeprazole 40 mg/day, and 65.8% with esomeprazole 80 mg/day; the corresponding percentages with pantoprazole were 28.6%, 36.9% and 44.9%, respectively. On a milligram-per-milligram basis, esomeprazole provided greater acid control than pantoprazole (p<0.001).

CONCLUSION

Dose escalation with oral esomeprazole and pantoprazole improves acid control in patients with GORD, although esomeprazole provides significantly greater acid control on a milligram-per-milligram basis.