Oral ranitidine as prophylaxis for gastric stress ulcers in intensive care unit patients: serum concentrations and cost comparisons

Bioavailability of Orally Administered Drugs in Critically Ill Patients

Critically ill patients managed in the Intensive Care Unit (ICU) suffer from several pathophysiological alterations due to critical illness resulting in potential changes in the pharmacokinetics of drugs including systemic absorption. Nevertheless, these patients are still given some medications in unadjusted doses thereby putting the patients at a risk for therapy failure. The objective for this study was to summarize the available evidence regarding oral drug absorption in the ICU. A literature search of the databases MEDLINE, EMBASE, and PubMed was conducted on (February 24, 2020). Articles discussing the rate and/or extent of orally administered drugs in critically ill patients were included. A total of 58 studies were found: 17 interventional studies, 33 observational studies (30 prospective, 3 retrospective) and 8 case reports. A total of 43 articles reported altered drug absorption in critically ill patients suggesting the need for alternative measures to facilitate treatment success. The absorption of orally administered drugs may be altered in critically ill patients. Measures for altered drug absorption in critically ill patients were suggested such as holding tube feeding before and after medication administration, increasing doses of orally administrated drugs and using alternate routes of administration.

Hepatic Failure

The progression of liver disease can cause several physiologic derangements that may precipitate hepatic failure and require admission to an intensive care unit. The underlying pathology may be acute, acute-on chronic, or chronic in nature. Liver failure may manifest with a variety of clinical signs and symptoms that need prompt attention. The compromised synthetic and metabolic activity of the failing liver affects all organ systems, from neurologic to integumentary. Supportive care and specific therapies should be instituted in order to improve outcome and minimize time of recovery.

In this chapter we will discuss the definition, clinical manifestations, workup, and management of acute and chronic liver failure and the general principles of treatment of these patients. Management of liver failure secondary to certain common etiologies will also be presented. Finally, liver transplantation and alternative therapies will also be discussed.

Therapeutic concerns when oral medications are administered nasogastrically

WHAT IS KNOWN AND OBJECTIVE

Administering oral medications to patients with nasogastric tube (NGT) is a challenging patient-care issue. Inappropriate prescribing behaviour and incorrect procedure for extemporaneous preparation of oral suspensions given via NGT may result in significant harm to patients. There are many drugs which have not been tested regarding oral absorption profile and bioavailability derived from NGT dosing. Although several studies and case-reports have been reported, there is no up-to-date review of drug administration via NGT. The aim of this review is to increase awareness of rational drug administration via NGT and to encourage relevant research in this area.

METHODS

Full prescribing information from each currently available oral medication was reviewed for any data indicating that the medication could not be crushed or opened. Literature was identified by searching PubMed (1988 to Aug 2012).

RESULTS AND DISCUSSION

There is evidence to show that NGT dosing of some medications may bring both benefits (e.g. cost saving) and disadvantages (e.g. decrease in efficacy and/or safety). For medications with package inserts that warn that they should not be crushed or opened, alternatives are usually recommended. However, in some cases, there is evidence to support NGT dosing. Sometimes special procedures are required to avoid problems such as instability, interaction with enteral nutrition, adsorption, tube obstruction and low recovery when preparing extemporaneous oral suspensions.

WHAT IS NEW AND CONCLUSION

Physicians, pharmacists and nurses should know the procedures for drug administration by NGT, as well as the latest evidence on such administrations. There may not be bioequivalence between oral and nasogastric administrations. Care must be taken to avoid compromising the physicochemical, biopharmaceutical and pharmacological properties of drugs given by NGT to ensure their safety and efficacy.

Stress-induced ulcer bleeding in critically ill patients

Increased knowledge of risk factors and improved ICU care has decreased the incidence of stress-related bleeding. Not all critically ill patients need prophylaxis for SRMD and withholding such prophylaxis in suitable low-risk candidates is a reasonable and cost-effective approach. Mechanical ventilation for more than 48 hours and coagulopathy are the main risk factors for stress-induced upper GI bleeding. Although intravenous H2RAs can prevent clinically important bleeding, their benefits seem to be limited by the rapid development of tolerance. The availability of intravenous formulations of PPIs makes it possible to critically compare their prophylactic efficacy and safety to different classes of acid-suppressive agents, such as H2RAs, in critically ill patients. The appropriate dose of PPI and the role of newer PPI formulations need to be further defined along with proposed guidelines for the use of intravenous and oral/enteral formulations of PPIs in patients at risk for stress-related mucosal damage.

Stress ulcer bleeding

Although upper gastrointestinal (GI) bleeding from stress-related mucosal disease (SRMD) in critically ill patients is common, significant bleeding with hemodynamic instability is not. Risk factor assessment can assist in identifying patients with a greater likelihood of developing significant SRMD. Prophylaxis against stress ulcer bleeding with luminal agents (eg, antacids and sucralfate) or drugs that inhibit acid secretion (eg, histamine 2-receptor antagonists and proton-pump inhibitors) can reduce major bleeding but has little or no effect on mortality. Currently, the mainstays of prophylactic therapy for SRMD are intravenously administered H2RAs and PPIs. Wider usage of PPIs reflects their enhanced efficacy in suppressing acid secretion as well as lack of tolerance for H2RAs. Guidelines for the prophylactic use of H2RAs or PPIs in treatment of SRMD will require large, randomized studies that also examine cost effectiveness of individual strategies.

Impact of stress ulcer prophylaxis algorithm study

BACKGROUND

In the intensive care unit at Royal Victoria Hospital, we noted that drugs prescribed for stress ulcer prophylaxis were not always indicated or optimal. Accordingly, we implemented an algorithm for stress ulcer prophylaxis to guide the medical team in their decisions. The agents selected for the algorithm were intravenous famotidine and omeprazole suspension or tablets, depending on the available administration route.

OBJECTIVE

To evaluate the impact of a treatment algorithm on the appropriateness of prescriptions for stress ulcer prophylaxis.

METHODS

A quasi-experimental-type evaluative study was conducted based on a pre-/post-intervention design without a concurrent control group. A total of 555 complete admissions met the selection criteria; 303 patients formed the pre-intervention group, and 252 made up the post-intervention group (exposed to the treatment algorithm).

RESULTS

After implementation of the algorithm, the proportion of inappropriate prophylaxis was decreased (95.7% vs 88.2%; p = 0.033). The number of days of inappropriate prophylaxis was also reduced significantly (p = 0.013), as was the cost per patient (p = 0.003) for all admissions. However, no difference was observed when the subgroup of patients who received prophylaxis alone was studied (p = 0.098 and p = 0.918). The presence of bleeding was similar in both groups.

CONCLUSIONS

Introduction by pharmacists of a treatment algorithm for stress ulcer prophylaxis in intensive care units allows a reduction of inappropriate prescriptions and thus a reduction in the cost of drugs. The use of omeprazole suspension seems to be an alternative to intravenous histamine2-inhibitors; however, a large-scale study is necessary to confirm the efficacy and safety of proton-pump inhibitors administered by an enteral tube.

Stress-related mucosal disease: risk factors and prophylactic therapy

BACKGROUND

The term stress-related mucosal disease (SRMD) represents a continuum of conditions ranging from stress-related injury (superficial mucosal damage) to stress ulcers (focal deep mucosal damage). Caused by mucosal ischemia, SRMD is most commonly seen in critically ill patients in the intensive care unit (ICU). Prophylaxis of stress ulcers may reduce major bleeding but has not yet been shown to improve survival.

OBJECTIVES

This article reviews currently available agents for the prophylaxis of SRMD and discusses their uses and potential adverse effects.

METHODS

Relevant articles in the English-language literature were identified through a MEDLINE search (1968-2003) using the key words stress-related mucosal disease, stress-related injury, ulcer, prophylaxis, intensive care unit, and upper gastrointestinal bleeding.

RESULTS

The most widely used drugs for stress-related injury are the intravenous histamine(2)-receptor antagonists. These drugs raise gastric pH but are associated with the development of tolerance and possible drug interactions and neurologic manifestations. Sucralfate, which can be administered by the nasogastric route, can protect the gastric mucosa without raising pH, but may decrease the absorption of concomitantly administered oral medications. The prostaglandin misoprostol has not been shown to be of benefit in the prophylaxis of SRMD. Antacids lower the risk of gastrointestinal bleeding, but large volumes of antacids are required and treatment is labor intensive. Proton pump inhibitors (PPIs) are the most potent acid-suppressive pharmacologic agents available. Esomeprazole, lansoprazole, omeprazole, pantoprazole, and rabeprazole substantially raise gastric pH for up to 24 hours after a single dose. The availability of an intravenous formulation of pantoprazole may help improve the treatment of SRMD in ICU patients, particularly those receiving mechanical ventilation. Tolerance does not develop, and few adverse effects have been reported.

CONCLUSIONS

Recent studies of PPIs have shown promising results in high-risk patients, making this class of drugs an option for the prophylaxis of SRMD.

Pharmacologic prophylaxis and treatment of stress ulcers in critically ill patients

Most clinicians agree that critically ill patients are at significant risk of developing stress-related ulcers and may have already developed mucosal lesions even if they are asymptomatic. Many options, including new pharmacologic advances, are available for the treatment and prophylaxis of stress-related ulcers; therefore, all critically ill patients should receive prophylaxis, even if they do not require treatment. Nutrition may play a significant role in the future in preventing stress-related ulcers. By improving stores of critical elements such as antioxidants, vitamins, and minerals before surgery, patients may lower the risk of developing stress ulcers. Critical care clinicians are critical in preventing and treating stress-related ulcers and should be vigilant in their patient care.

Gastrointestinal problems in the chronically critically ill patient

In summary, a variety of gastrointestinal processes may occur in the chronically critically ill patient population, usually as consequence of the primary systemic process. The clinical presentation is frequently nonclassic and there often is a substantial delay in diagnosis, resulting in increased morbidity and mortality.

Economic evaluations in the critical care literature: do they help us improve the efficiency of our unit?

OBJECTIVE

To determine the extent to which economic evaluations published in the critical care literature provide information that can help us to improve the efficiency of our unit.

DATA SOURCES

We searched computerized bibliographic databases and manually searched key critical care journals to retrieve all economic evaluations.

STUDY SELECTION

We included economic evaluations that dealt with clinical problems relevant to the practice of adult critical care and that compared competing healthcare interventions.

DATA ABSTRACTION

Included articles were further evaluated using criteria for minimal methodologic soundness, adopted from the literature, and criteria that we developed to assess the generalizability of results to our clinical setting.

DATA SYNTHESIS

We screened 4,167 papers manually and > 450 abstracts and titles in our computer search. One hundred fifty-one papers were retrieved for further evaluation; 29 papers met our inclusion criteria. Of these 29 papers, only 14 (48%) adequately described competing healthcare interventions, 17 (59%) provided sufficient evidence of clinical efficacy, six (21%) identified, measured, and valuated costs appropriately, and three (10%) performed a sensitivity analysis. None of the papers met all four of these criteria for a minimum level of methodologic soundness. Four (14%) of 29 studies which adequately dealt with issues of cost and efficacy were evaluated using our generalizability criteria. Different costing methods precluded the application of the results of three of the four studies to our intensive care unit.

CONCLUSIONS

In the critical care literature, very little useful economic information exists to help decision-makers maximize efficiency in their own setting.

Changing perspectives of stress gastritis prophylaxis

OBJECTIVE

To present recent advances in stress gastritis prophylaxis in the critically ill and review considerations in selection of a prophylactic agent.

DATA SOURCES

Information was obtained from MEDLINE search, reference lists from articles identified in search, and from review articles.

STUDY SELECTION

Emphasis was placed on controlled trials conducted within the last 5 years.

DATA EXTRACTION

All literature was assessed for methodology, results, and conclusions. Results of prospective, randomized trials, and meta-analyses are summarized.

DATA SYNTHESIS

Histamine2-receptor antagonists, antacids, and sucralfate appear equally effective in preventing stress gastritis in the critically ill. A definitive cause-effect relationship between histamine2-receptor antagonists and increased incidence of nosocomial pneumonia has not yet been established. The indications for using a prophylactic agent and consideration in selecting an agent should include an evaluation of the following: risk factors for gastritis including the type of intensive care patient, comparative efficacy, adverse effects, drug interactions, cost, and ease of administration. The least expensive, safest agent requiring minimal monitoring is sucralfate. Prevention of stress gastritis has never been shown to reduce morbidity or mortality significantly.

CONCLUSIONS

Controversies still exist regarding the need to provide prophylaxis, the choice of an agent, and the relative importance of previously identified risk factors. Further well-designed studies are needed before consensus can be reached.