Enteral Delivery of Pravastatin Sodium Tablets: Effect of Compounding into a Liquid Form and Co-Administration of Enteral Nutrition

BACKGROUND

Compounding solid oral dosage forms into liquid preparations is a common practice for administering drug therapy to patients with swallowing difficulties. This is particularly relevant for those on enteral nutrition, where factors such as the administration procedure and co-administration of enteral nutrition play crucial roles in effective drug delivery. Due to the limited studies focused on this practice, the impact of co-administered nutrition remains unclear.

METHODS

Pravastatin tablets were compounded into two liquid formulations and administered through three independent tubes for ten cycles. The drug amount was quantified upstream and downstream of the tubes both with and without different (fiber content) nutritional boluses.

RESULTS

The compounding procedure did not lower the drug amount with respect to the original tablets. However, when the liquid formulation was pumped through the tubes, a statistically significant reduction in the pravastatin administered (between 4.6% and 11.3%) was observed. The co-administration of different nutritional boluses or the compounding procedure did not affect the general results.

CONCLUSIONS

Pravastatin loss appears unavoidable when administered via the enteral tube. Although, in this case, the loss was of limited clinical relevance, it is important not to underestimate this phenomenon, especially with drugs having a narrow therapeutic index.

Discharged on Enteral Nutrition: What Now? The Poor State of Outpatient Support for Patients on Enteral Nutrition Support

PURPOSE OF REVIEW

While the use of enteral nutrition (EN) has increased, and more medical centers have developed inpatient programs to address the unique needs of these patients, our collective experience at a few large institutions indicates that there is very little systemic support for patients after discharge. Here, we discuss what we have observed to be some of the barriers to providing outpatient follow up care, summarize the impact we have seen on patients, and propose some possible solutions.

RECENT FINDINGS

We have observed and identified some of the root causes to include financial barriers; uncoordinated care transitions; high complexity of care, including medication management; and diffuse leadership to a multidisciplinary problem. Systematic support for outpatient care for patients discharged on enteral nutrition is rare and limited, due to many root causes. There are a few tools and tips that we have summarized here for individual providers, and a few promising methods in development, but a systematic approach is in great need.

Enteral Medication for the Tube-Fed Patient: Making This Route Safe and Effective

The administration of medication through an enteral access device requires important forethought. Meeting a patient's therapeutic needs requires achieving expected drug bioavailability without increasing the risk for toxicity, therapeutic failure, or feeding tube occlusion. Superimposing gut dysfunction, critical illness, or enteral nutrition-drug interaction further increases the need for a systematic approach to prescribing, evaluating, and preparing a drug for administration through an enteral access device. This review will explain the fundamental factors involved in drug bioavailability through the gut, address the influencing considerations for the enterally fed patient, and describe best practices for enteral drug preparation and administration.

Warfarin and food, herbal or dietary supplement interactions: A systematic review

AIMS

To present an updated overview on the safety of concurrent use of food, herbal or dietary supplement and warfarin.

METHODS

A systematic literature review was performed on 5 databases from inception up to 31 December 2019. These interactions were classified depending on the likelihood of interaction and supporting evidences.

RESULTS

A total of 149 articles describing 78 herbs, food or dietary supplements were reported to interact with warfarin. These reports described potentiation with 45 (57.7%) herbs, food or dietary supplements while 23 (29.5%) reported inhibition and 10 (12.8%) reported limited impact on warfarin pharmacokinetics and pharmacodynamics. Twenty unique herb and dietary supplements also reported to result in minor bleeding events, such as purpura and gum bleeding as well as major events such as intracranial bleeding that led to death.

CONCLUSION

While most food, herbs and supplements can be safely taken in moderation, healthcare professionals should be aware of the increased risk of bleeding when taking several food and herbs. These include Chinese wolfberry, chamomile tea, cannabis, cranberry, chitosan, green tea, Ginkgo biloba, ginger, spinach, St. John's Wort, sushi and smoking tobacco. Patients should be counselled to continue to seek advice from their healthcare professionals when starting any new herbs, food or supplement.

Pharmacists in Critical Care

The beginnings of caring for critically ill patients date back to Florence Nightingale's work during the Crimean War in 1854, but the subspecialty of critical care medicine is relatively young. The first US multidisciplinary intensive care unit (ICU) was established in 1958, and the American Board of Medical Subspecialties first recognized the subspecialty of critical care medicine in 1986. Critical care pharmacy services began around the 1970s, growing in the intervening 40 years to become one of the largest practice areas for clinical pharmacists, with its own section in the SCCM, the largest international professional organization in the field. During the next decade, pharmacy services expanded to various ICU settings (both adult and pediatric), the operating room, and the emergency department. In these settings, pharmacists established clinical practices consisting of therapeutic drug monitoring, nutrition support, and participation in patient care rounds. Pharmacists also developed efficient and safe drug delivery systems with the evolution of critical care pharmacy satellites and other innovative programs. In the 1980s, critical care pharmacists designed specialized training programs and increased participation in critical care organizations. The number of critical care residencies and fellowships doubled between the early 1980s and the late 1990s. Standards for critical care residency were developed, and directories of residencies and fellowships were published. In 1989, the Clinical Pharmacy and Pharmacology Section was formed within the Society of Critical Care Medicine, the largest international, multidisciplinary, multispecialty critical care organization. This recognition acknowledged that pharmacists are necessary and valuable members of the physician-led multidisciplinary team. The Society of Critical Care Medicine Guidelines for Critical Care Services and Personnel deem that pharmacists are essential for the delivery of quality care to critically ill patients. These guidelines recommend that a pharmacist monitor drug regimen for dosing, adverse reactions, drug-drug interactions, and cost optimization for all hospitals providing critical care services. The guidelines also advocate that a specialized, decentralized pharmacist provide expertise in nutrition support, cardiorespiratory resuscitation, and clinical research in academic medical centers providing comprehensive critical care.

Total Parenteral and Enteral Nutrition in the ICU: Evolving Concepts

Appropriate nutrition in the hospital setting, particularly in critically ill patients, has long been tied to improving clinical outcomes. During critical illness, inflammatory mediators and cytokines lead to the creation of a catabolic state to facilitate the use of endogenous energy sources to meet increased energy demands. This process results in increasing the likelihood of overfeeding. The literature has revealed exponential advances in understanding the molecular basis of nutritional support and evolution of clinical protocols aimed at treating artificial nutritional support as a therapeutic intervention, preventing loss of lean body mass and metabolic deterioration to improve clinical outcomes in the critically ill.

Administration of Direct Oral Anticoagulants Through Enteral Feeding Tubes

Objective: To review literature regarding direct oral anticoagulants (DOACs) and determine their viability of administration in solution or via enteral tubes. Data Sources: MEDLINE literature searches identified articles published 2007-present using MeSH terms: factor Xa inhibitors, antithrombins, biological availability, and enteral nutrition. Package inserts were included. Manufacturers were asked to provide literature. Study Selection and Data Extraction: We included studies emphasizing bioavailability or enteral administration. Data Synthesis: Dabigatran and edoxaban package inserts recommend against altering the dosage form, and against enteral administration. One rivaroxaban study was identified. Given with food, enteral administration was comparable to the oral tablet. The mean AUC (0.889, 90% CI 86.12-91.84%) was within the equivalency margins; however Cmax (0.820, 90% CI 78.84-85.86%) was slightly below the 80% threshold. One apixaban study was identified. They showed bioequivalence between oral and enteral administration in different vehicles, but decreased bioavailability when crushed tablets were given along with nutritional support. AUC and Cmax were 32% and 19% lower, respectively, when apixaban solution was given via nasogastric (NG) tube with nutritional supplement versus oral administration of solution. Conclusions: Dabigatran capsules should not be altered, due to large variations in drug exposure. Rivaroxaban can be given as oral solution or via NG tube. Larger doses must be given with nutritional supplementation and enteral tubes must not be distal to the stomach. Apixaban can be given as oral solution or via nasogastric or gastric tube on an empty stomach. Food impairs bioavailability of the crushed tablets. There are insufficient data to recommend enteral administration of edoxaban and the package insert recommends against altering tablets.

[A Systematic Review of the Acceptable Intake Level of Vitamin K among Warfarin Users]

The interaction of warfarin and vitamin K is a clinically significant issue. This study investigated the acceptable intake level of vitamin K among warfarin users by means of a systematic review. We searched two databases (PubMed and "Igaku chuo zasshi")for articles about adverse events arising from interaction of warfarin and vitamin K, published until October 2014. Of 1,310 citations retrieved, 16 studies met the selection criteria for examination of the upper limit, and 6 studies dealt with amounts below the limit. The intake of vitamin K in warfarin patients was acceptable in the range of 25-325 μg/day, with a maximum daily variation of 292 μg, and a value of 150 μg/day seemed optimum. When these results were applied to usual foods, except for dietary supplements or health foods, the only prohibited foods were fermented soybean (natto) and foods containing it, while green leafy vegetables could be acceptable if their intake is limited.

Reducing medication errors in critical care: a multimodal approach

The Institute of Medicine has reported that medication errors are the single most common type of error in health care, representing 19% of all adverse events, while accounting for over 7,000 deaths annually. The frequency of medication errors in adult intensive care units can be as high as 947 per 1,000 patient-days, with a median of 105.9 per 1,000 patient-days. The formulation of drugs is a potential contributor to medication errors. Challenges related to drug formulation are specific to the various routes of medication administration, though errors associated with medication appearance and labeling occur among all drug formulations and routes of administration. Addressing these multifaceted challenges requires a multimodal approach. Changes in technology, training, systems, and safety culture are all strategies to potentially reduce medication errors related to drug formulation in the intensive care unit.

Inadvertent exaggerated anticoagulation following use of bismuth subsalicylate in an enterally fed patient receiving warfarin therapy

We report a case of an inadvertent increase in the international normalized ratio (INR) after the addition of bismuth subsalicylate for the treatment of diarrhea in an enterally fed patient receiving warfarin therapy. A 56-year-old Caucasian female presented to the trauma intensive care unit (ICU) with multiple lower extremity fractures. Warfarin was initiated for deep vein thrombosis prophylaxis due to the patient's inability to ambulate. The target INR was 2-3. Continuous intragastric enteral feeding was withheld 1 hour before and 1 hour after intragastric administration of warfarin. Bismuth subsalicylate 30 mL every 4 hours was prescribed for diarrhea. Within 3 days after starting bismuth subsalicylate therapy, the patient's INR increased from 2.56 to 3.54 and minor bleeding was noted from the patient's tracheostomy site. No significant change in warfarin dosage, variability in vitamin K intake, or medications that potentially alter warfarin metabolism were present during the unexpected rise in INR. When the bismuth subsalicylate was discontinued, the patient's INR stabilized into the target range on the same warfarin dose given at the time of the supratherapeutic INR. Salicylate displaces warfarin from plasma protein binding sites and may result in a significant increase in INR secondary to redistribution of warfarin to the free active form. Evaluation of this case report using the Drug Interaction Probability Scale and Naranjo Adverse Drug Reaction Probability Scale yielded scores consistent with a probable adverse drug interaction. Bismuth subsalicylate exaggerates warfarin's anticoagulant response and its concurrent use during warfarin therapy should be avoided.

Drug-nutrient interactions

Drug-nutrient interactions are defined as physical, chemical, physiologic, or pathophysiologic relationships between a drug and a nutrient. The causes of most clinically significant drug-nutrient interactions are usually multifactorial. Failure to identify and properly manage drug-nutrient interactions can lead to very serious consequences and have a negative impact on patient outcomes. Nevertheless, with thorough review and assessment of the patient's history and treatment regimens and a carefully executed management strategy, adverse events associated with drug-nutrient interactions can be prevented. Based on the physiologic sequence of events after a drug or a nutrient has entered the body and the mechanism of interactions, drug-nutrient interactions can be categorized into 4 main types. Each type of interaction can be managed using similar strategies. The existing data that guide the clinical management of most drug-nutrient interactions are mostly anecdotal experience, uncontrolled observations, and opinions, whereas the science in understanding the mechanism of drug-nutrient interactions remains limited. The challenge for researchers and clinicians is to increase both basic and higher level clinical research in this field to bridge the gap between the science and practice. The research should aim to establish a better understanding of the function, regulation, and substrate specificity of the nutrient-related enzymes and transport proteins present in the gastrointestinal tract, as well as assess how the incidence and management of drug-nutrient interactions can be affected by sex, ethnicity, environmental factors, and genetic polymorphisms. This knowledge can help us develop a true personalized medicine approach in the prevention and management of drug-nutrient interactions.

Drug-nutrient interactions in the intensive care unit: literature review and current recommendations

OBJECTIVE

To describe the interactions between drugs and nutrients and their frequency in the intensive care unit and to assess the professional team's awareness regarding this subject.

METHODS

The keywords "drug interactions" and "nutrition therapy" were searched in the PubMed (specifically MeSH) electronic database. The studies were systematically reviewed for descriptions of the types of interactions between drugs and nutrients, including their frequency and consequences.

RESULTS

Sixty-seven articles were found. Among these, 20 articles were appropriate for the methodology adopted and accomplished the objectives of the study. Of these 20 articles, 14 articles described interactions between drugs and enteral nutrition, three described interactions between drugs and parenteral nutrition, and three described the importance and care required to avoid such interactions.

CONCLUSIONS

The literature about drug and nutrient interactions is limited and suggests the inability of health care teams to recognize the potential for these interactions. Possibly, the elaboration of a protocol to evaluate drug-nutrient interactions will increase the safety and efficacy of therapeutics.

Warfarin Resistance and Enteral Tube Feeding: An Old Problem with a New Solution

Nutrition Support Pharmacist features issues pertinent to the practice of clinical pharmacy in the area of metabolic support.

Recent Publications on Medications and Pharmacy

Hospital Pharmacy presents this feature to keep pharmacists abreast of new publications in the medical/pharmacy literature. Articles of interest will be abstracted monthly regarding a broad scope of topics. Suggestions or comments may be addressed to: Jacyntha Sterling, Drug Information Specialist at Saint Francis Hospital, 6161 S Yale Ave., Tulsa, OK 74136 or e-mail: jasterling@saintfrancis.com .