Proton pump inhibitor formulary considerations in the acutely ill. Part 1: Pharmacology, pharmacodynamics, and available formulations

The impact of pharmacist intervention on the intravenous-to-oral switch therapy of proton pump inhibitors in cardiovascular surgery

BACKGROUND

The prescriptions of proton pump inhibitors (PPIs) have been widely concerned due to both huge increase in medical costs and possible long-term adverse events (AEs) caused by the improper route of drug administration. The aim of this study was to assess the effectiveness of pharmacist interventions on the clinical outcome and safety of switching from intravenous (IV) to oral PPIs therapy.

PATIENTS AND METHODS

A retrospective, single-center, pre- intervention (early -stage)- and intervention (later -stage) study was performed in a Chinese hospital.

RESULTS

A total of 1736 patients were included in the study. After 12 months of interventions, significant improvements in the number of rational IV to oral switch in patients with oral switch indications were found. The median duration of oral therapy was increased, while the duration of PPIs therapy was decreased. Pharmacist interventions led to significant reductions in mean PPI costs, mean total drug costs, mean hospitalization costs, and the risk for long-term adverse events.

CONCLUSION

This study provides important evidence on the beneficial effect of pharmacist interventions on promoting an optimal IV to oral switch of PPIs and substantial cost saving by shortening the duration of IV PPIs therapy and reducing the risk for long-term AEs.

Multi-indication Pharmacotherapeutic Multicriteria Decision Analytic Model for the Comparative Formulary Inclusion of Proton Pump Inhibitors in Qatar

PURPOSE

The formulary inclusion of proton pump inhibitors (PPIs) in the government hospital health services in Qatar is not comparative or restricted. Requests to include a PPI in the formulary are typically accepted if evidence of efficacy and tolerability is presented. There are no literature reports of a PPI scoring model that is based on comparatively weighted multiple indications and no reports of PPI selection in Qatar or the Middle East. This study aims to compare first-line use of the PPIs that exist in Qatar. The economic effect of the study recommendations was also quantified.

METHODS

A comparative, evidence-based multicriteria decision analysis (MCDA) model was constructed to follow the multiple indications and pharmacotherapeutic criteria of PPIs. Literature and an expert panel informed the selection criteria of PPIs. Input from the relevant local clinician population steered the relative weighting of selection criteria. Comparatively scored PPIs, exceeding a defined score threshold, were recommended for selection.

FINDINGS

Weighted model scores were successfully developed, with 95% CI and 5% margin of error. The model comprised 7 main criteria and 38 subcriteria. Main criteria are indication, dosage frequency, treatment duration, best published evidence, available formulations, drug interactions, and pharmacokinetic and pharmacodynamic properties. Most weight was achieved for the indications selection criteria. Esomeprazole and rabeprazole were suggested as formulary options, followed by lansoprazole for nonformulary use. The estimated effect of the study recommendations was up to a 15.3% reduction in the annual PPI expenditure. Robustness of study conclusions against variabilities in study inputs was confirmed via sensitivity analyses.

IMPLICATIONS

The implementation of a locally developed PPI-specific comparative MCDA scoring model, which is multiweighted indication and criteria based, into the Qatari formulary selection practices is a successful evidence-based cost-cutting exercise. Esomeprazole and rabeprazole should be the first-line choice from among the PPIs available at the Qatari government hospital health services.

Efficacy of ilaprazole in the treatment of duodenal ulcers: A meta-analysis

AIM: To compare the efficacy and tolerance of ilaprazole compared with other proton pump inhibitors (PPIs) in the treatment of duodenal ulcer.

METHODS: An electronic database search of Medline, Embase, the Cochrane controlled trials register, Web of Science, PubMed, and the Chinese Biomedical Literature Database (updated to July 2013), and manual searches were conducted. A meta-analysis of randomized controlled trials comparing the efficacy and tolerance of ilaprazole and other PPIs in the treatment of duodenal ulcers was performed.

RESULTS: Five articles involving 1481 patients were included. The meta-analysis showed no difference in the 4-wk healing rate between ilaprazole and other PPIs [89.7% vs 87.0%; relative risk (RR) = 1.02; 95%CI: 0.98-1.06; Z = 1.00; P = 0.32]. The results did not change in the sensitivity analyses. The meta-analysis indicated that the adverse effect rate in the ilaprazole group was lower than that in the control group, but the difference was not significant (9.7% vs 13.0%; RR = 0.81; 95%CI: 0.60-1.07; Z = 1.47; P = 0.14).

CONCLUSION: Ilaprazole is a highly effective and safe PPI in the treatment of duodenal ulcers. Ilaprazole can be recommended as a therapy for acid-related disorders, especially in Asian populations.

Off-Label Use of Gastrointestinal Medications in the Intensive Care Unit

Purpose:

Determine the level of evidence supporting off-label gastrointestinal (GI) medication use and identify the medication class and indication whereby off-label use was most common.

Materials and Methods:

This prospective, multicentered observational study evaluated all medication orders written in 37 intensive care units (ICUs) in the United States, over a 24-hour period. All medications classified as “GI” according to a national reference were identified. The class and indication whereby off-label use was most prominent were determined and the level of evidence was described.

Results:

There were 774 orders from 363 patients and 63% (489 of 774) were considered off-label. Proton pump inhibitors (PPIs) accounted for most of the off-label usage (55% [271 of 489]), followed by laxatives (16% [77 of 489]) and histamine-2-receptor antagonists (H2RAs; 15% [71 of 489]). When prescribed, 99% (271 of 274) of PPIs, 99% (71 of 72) of H2RAs, and 79% (30 of 38) of promotility agents were off-label. Stress ulcer prophylaxis (100% [309 of 309]), GI bleeding (100% [18 of 18]), and gastric motility (88% [30 of 34]) were the most common off-label indications. The most common strength of recommendation and level of evidence for off-label use was indeterminate (58% [282 of 489]) and none (57% [280 of 489]), respectively.

Conclusion:

The PPIs are the most widely used off-label medications in the ICU. Stress ulcer prophylaxis is the most common indication. The level of evidence supporting off-label GI medication use is poor.

Drug absorption, distribution, metabolism and excretion considerations in critically ill adults

INTRODUCTION

All critically ill patients require medication to treat organ dysfunction. However, the pharmacokinetics of drugs used to treat these patients is complex due to frequent alterations in drug absorption, distribution, metabolism, and excretion (ADME).

AREAS COVERED

This review examines pharmacokinetic aspects of drug administration for adult intensive care unit (ICU) patients. Specifically, the authors examine the ADME changes that occur and which should be considered by clinicians when delivering drug therapy to critically ill patients.

EXPERT OPINION

Dosage pharmacokinetics determined from single-dose or limited-duration administration studies in healthy volunteers may not apply to critically ill patients. Organ dysfunction among these patients may be due to pre-existing disease or the effects of a systemic or locoregional inflammatory response precipitated by their illness. Alterations in pharmacokinetics observed among the critically ill include altered bioavailability after enteral administration, increased volume of distribution and blood-brain barrier permeability and changes in P-glycoprotein and cytochrome P450 enzyme function. However, the effect of these changes on clinically important outcomes remains uncertain and poorly studied. Future investigations should examine not only pharmacokinetic changes among the critically ill, but also whether recognition of these changes and alterations in drug therapy directed as a consequence of their observation alters patient outcomes.

Overutilization of proton-pump inhibitors: what the clinician needs to know

Proton-pump inhibitors (PPIs) remain the leading evidence-based therapy for upper gastrointestinal disorders, including gastroesophageal reflux disease, dyspepsia, and peptic ulcer disease. The effectiveness of PPIs has led to overutilization in multiple treatment arenas, exposing patients to an increasing number of potential risks. The overutilization of PPIs in ambulatory care settings is often a result of failure to re-evaluate the need for continuation of therapy, or insufficient use of on-demand and step-down therapy. PPI overutilization in the inpatient setting is often a result of inappropriate stress ulcer prophylaxis (SUP) in nonintensive care unit patients, and failure to discontinue SUP prior to hospital discharge. Potential consequences of prolonged PPI therapy include hypergastrinemia, enterochromaffin-like cell hyperplasia, and parietal cell hypertrophy, leading to rebound acid hypersecretion. PPIs have been linked via retrospective studies to increased risk of enteric infections including Clostridium difficile-associated diarrhea, community-acquired pneumonia, bone fracture, nutritional deficiencies, and interference with metabolism of antiplatelet agents. Reducing inappropriate prescribing of PPIs in the inpatient and outpatient settings can minimize potential for adverse events, and foster controllable cost expenditure.

Intravenous esomeprazole pharmacodynamics in critically ill patients

OBJECTIVE

A widely held belief contends that food-induced proton pump activation is important for optimal proton pump inhibitor-induced inhibition of gastric acid secretion. This study was undertaken to assess intragastric acid control with intravenous (IV) esomeprazole in critically ill patients.

RESEARCH DESIGN AND METHODS

This open-label, single-arm, exploratory trial was conducted at five university or regional hospital intensive care units in the US. Adult patients admitted to an intensive care unit who required mechanical ventilation and had at least one additional risk factor for stress-induced ulcer received twice-daily IV esomeprazole 40 mg for 48 hours and could continue for another 24 hours if no prepyloric enteral feedings were planned.

CLINICAL TRIAL REGISTRATION

D9612L00107; ClinicalTrials.gov Identifier NCT00428701.

MAIN OUTCOME MEASURES

The primary efficacy variable was the linear-interpolated percentage of time intragastric pH was > or =4 during 24-48 hours. Secondary efficacy variables included the interpolated percentage of time intragastric pH was > or =4 during 0-24, 0-48, and 48-72 hours, the percentage of gastric aspirates collected with pH > or =4 during 0-24, 24-48, 0-48, and 48-72 hours, and time to stable pH > or =4. Safety was assessed based on adverse events (AEs), physical examinations, vital signs, laboratory tests, and electrocardiograms.

RESULTS

Forty-five patients were enrolled (one was excluded because of previous partial gastrectomy). Interpolated mean percentage time pH > or =4 was 88.8%, 80.7%, and 83.5% for 24-48, 0-24, and 0-48 hours, respectively. For 0-72 hours, > or =78% of gastric aspirates had pH > or =4. Median time to stable pH was 1 hour (95% confidence interval: 0.67, 2.00). Treatment was well tolerated, with no evidence of gastrointestinal bleeding. A total of 75 AEs occurred in 34 patients, none considered treatment related.

CONCLUSIONS

In this noncontrolled exploratory study, twice-daily IV esomeprazole 40 mg rapidly decreased intragastric acidity and effectively maintained pH >/=4 during 0-72 hours in fasting, critically ill, mechanically ventilated patients at high risk for stress ulcers.

Gastrointestinal prophylaxis in critically ill patients

Physiologic stress associated with illness and hospitalization is known to result in gastrointestinal ulceration, especially among the critically ill. The complication of this stress-related mucosal disease could be prevented with appropriate application of pharmacologic prophylaxis. Vigilance by the nursing staff is required to properly detect and manage the condition.

Comparison of the enteral and intravenous lansoprazole pharmacodynamic responses in critically ill patients

BACKGROUND

While proton pump inhibitors are frequently administered in the intensive care unit, the pharmacodynamic response of acid suppression between the enteral and intravenous (IV) route is unknown.

AIM

To compare the pharmacodynamic response between enteral and IV lansoprazole in intensive care unit patients requiring stress ulcer prophylaxis therapy.

METHODS

Adult mechanically ventilated patients were randomized to receive 72 h of daily enteral [lansoprazole oral disintegrating tablet (LODT) 30 mg mixed in 10 mL of water via a nasal gastric tube] or IV lansoprazole (30 mg over 30 min) therapy. Serial blood samples were collected after the first and third dose and analysed for pharmacokinetic parameters. Pharmacodynamic determination of intragastric pHmetry began prior to the first dose and continued for 72 h using a single channel pH microelectrode.

RESULTS

Nineteen intensive care unit patients were randomized [LODT (n = 10); IV-L (n = 9)]. LODT bioavailability was 76%. LODT maintained gastric pH > 4 longer than IV-L at both 24 h (7.4 vs. 5.9 h; P = 0.039) and 72 h (10.4 and 8.9 h; P = 0.046) and resulted in a greater average pH over the first 24 h (3.67 vs. 2.89; P = 0.03).

CONCLUSION

Despite a lower bioavailability, enteral lansoprazole suppresses acid in intensive care unit patients to a greater extent than IV lansoprazole.

[Drug interchangeability: clinical approach and consumer's point of view]

The rational construction of an essential drug list, considering the patient's need, drug safety, availability and the best cost-benefit ratio, is based on drug safety, efficacy and quality. However, in daily practice, the prescriber's decision is mostly influenced by drug effectiveness, following criteria that increase adherence to the treatment, such as relative drug toxicity, convenience, cost and prescriber's experience. In addition, frequent launching of new molecules for the same therapeutic indication, together with wide publicity targeting prescribers, interferes with the decision-making process. Similarly, the bonuses offered by the industry for over-the-counter drug sales interfere with the consumer's choice. The confrontation between known human biological variability and the knowledge that there is no absolute similarity between drugs of the same therapeutic class, or even generic drugs, has an impact on the prescriber's drug list, which should include the concept of first and second choice drugs. Prescribers' unfamiliarity with these subjects is a determinant factor for irrational drug use: a public health issue. The objective of this study was to introduce to drug prescribers information that can help them building up a rational drug list for their patients, based on the National Health Surveillance Agency (Anvisa) experience of drug regulation.

Intravenous pantoprazole utilization in a level 1 trauma center

BACKGROUND

In recent years there has been a rapid increase in the use of proton pump inhibitors. Our institution has recently had several shortages of IV pantoprazole, each lasting 7-10 days. The purpose of our study was to evaluate in-patient usage of IV pantoprazole. We hypothesized that hospitalized patients with upper gastrointestinal bleeding (GIB) or risk for stress ulcers inappropriately received IV pantoprazole based on current literature.

METHODS

This was a retrospective study of 165 consecutive in-patients identified as receiving pantoprazole from December 2004 to March 2005. Only patients receiving IV pantoprazole were included (n = 78). Data collected included demographics, indication and dosing of pantoprazole, admitting team (surgery vs. medicine), and risk factors for stress ulcers.

RESULTS

Our study population had a mean age of 54 +/- 17 years and 62% were male. Overall, 45% (35/78) of patients receiving IV pantoprazole had an appropriate indication, and 19% (15/78) received the correct dose. Of the 78 patients, 43 (55%) were treated with pantoprazole for stress ulcer prophylaxis (SUP), and 35 (45%) patients were treated for GIB. We found that none of the 43 patients treated for SUP had an appropriate indication for pantoprazole, but all of the patients with GIB (35) had an appropriate indication. Of the 35 patients treated for GIB with pantoprazole, only 40% (14/35) received the correct dose. In all cases of incorrect dosing, the patients were underdosed.

CONCLUSIONS

Pantoprazole is not being prescribed appropriately for stress ulcer prophylaxis in our patient population. Even in patients appropriately receiving pantoprazole the majority were prescribed an incorrect dose. Appropriate indications and dosing of pantoprazole could eliminate the shortages seen at our institution.

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.

Stability and compatibility of histamine H2-receptor antagonists in parenteral nutrition mixtures

PURPOSE OF REVIEW

To examine the stability and compatibility of histamine H2-receptor antagonists in parenteral nutrition admixtures in order to provide well tolerated and effective therapy.

RECENT FINDINGS

Many stability investigations were carried out before 2005, but no critical appraisal of published data has been undertaken. H2-receptor antagonists are stable in most parenteral nutrition admixtures for 2-48 h, with long-term stability up to 4 weeks claimed for a few combinations. Some earlier data are questionable in the light of more recent analytical technology and pharmaceutical knowledge regarding stability assessment. As stability is dependent upon the source of constituents, we have listed all products tested and their respective manufacturers. A general recommendation is made not to store H2-receptor antagonists in parenteral nutrition for more than 24 h at refrigerated temperature before use.

SUMMARY

Administration of H2-receptor antagonists in parenteral nutrition admixtures has several clinical and economical advantages, but, in order for these benefits to be well tolerated and efficacious, the stability and compatibility of the drugs, as well as the parenteral nutrition components after mixing, have to be ascertained. Factors that influence stability are assessed, the need for more controlled study protocols is evaluated and recommendations are made for safe storage and administration.

An in vitro comparison of different providers to deliver four proton pump inhibitor products through a feeding tube

BACKGROUND

It is unclear how delivery through a feeding tube compares between esomeprazole in water, lansoprazole oral disintegrating tablet in water, omeprazole/NaHCO(3) in water and simplified lansoprazole suspension.

AIM

This in vitro study compared delivery through a narrow calibre (8F) feeding tube among four proton pump inhibitors when given by skilled [nurse; (n = 8)] or unskilled [lay; (n = 8)] providers.

METHODS

Following standard instruction, subjects were observed delivering each proton pump inhibitor in a sequential, but random, fashion to evaluate administration quality and time. Delivery was quantified using high-performance liquid chromatography methods and subject preferences were evaluated.

RESULTS

Delivery (%), similar between lansoprazole oral disintegrating tablet (95.7 +/- 3.2) and omeprazole/NaHCO(3) (96.1 +/- 3.0), was both greater for lansoprazole oral disintegrating tablet than esomeprazole in water (88.9 +/- 8.6; P = 0.006) or simplified lansoprazole suspension (86.1 +/- 9.5; P = 0.0001) and omeprazole/NaHCO(3) than esomeprazole in water (P = 0.004) or simplified lansoprazole suspension (P < 0.001), and was not affected by prior subject experience. Quality was higher with both omeprazole/NaHCO(3) and lansoprazole oral disintegrating tablet than simplified lansoprazole suspension. Administration was quicker for lansoprazole oral disintegrating tablet than esomeprazole in water. Subjects preferred lansoprazole oral disintegrating tablet and omeprazole/NaHCO(3).

CONCLUSIONS

When given through an in vitro feeding tube, omeprazole/NaHCO(3) and lansoprazole oral disintegrating tablet lead to greater drug delivery, improved administration quality and higher user satisfaction, than either esomeprazole in water or simplified lansoprazole suspension.