Drug administration via feeding tubes-a procedure that carries risks: systematic identification of critical factors based on commonly administered drugs in a cohort of stroke patients

PURPOSE

Drug administration via feeding tubes is considered a process with many uncertainties. This review aimed to give a comprehensive overview of data available on feeding tube application and to carry out risk assessments for drug substances commonly administered to stroke patients.

METHODS

Drugs frequently administered via feeding tubes were identified through a retrospective analysis of discharge letters from a stroke unit. Physicochemical, pharmacokinetic, and stability properties of these drugs and data on drug-enteral nutrition interactions were systematically searched for in the European Pharmacopoeia, Hagers Handbook of Pharmaceutical Practice, Birchers clinical-pharmacological data compilation, and the Martindale Complete Drug Reference, as well as from databases including DrugBank, DrugDex, PubChem, Google Scholar, and PubMed.

RESULTS

Of the drugs most commonly administered via feeding tubes in the present stroke patient cohort, bisoprolol, candesartan, and ramipril could be considered the least critical due to their overall favourable properties. Acetylsalicylic acid, amlodipine, hydrochlorothiazide, omeprazole and esomeprazole, simvastatin, and torasemide pose risks based on pH or light-dependent instability or proposed food effects. The most critical drugs to be administered via feeding tubes are considered to be furosemide, levodopa, and levothyroxine as they show relevant instabilities under administration conditions and substantial food effects; the latter two even possess a narrow therapeutic index. However, little information is available on drug-tube and drug-formula interactions.

CONCLUSION

Feeding tube administration of medications turned out to be a highly complex process with several unmet risks. Therefore, investigations that systematically assess these risk factors using clinically relevant model systems are urgently needed.

Medications and Food Interfering with the Bioavailability of Levothyroxine: A Systematic Review

Purpose

Levothyroxine is a common prescribed drug. Many medications and food, however, can interfere with its bioavailability. The aim of this review was to summarize the medications, food and beverages that interact with levothyroxine and to assess their effects, mechanisms and treatments.

Methods

A systematic review on interfering substances that interact with levothyroxine was performed. Web of Science, Embase, PubMed, the Cochrane library, grey literature from other sources and the lists of references were searched for human studies comparing the levothyroxine efficacy with and without interfering substances. The patient characteristics, drug classes, effects and mechanism were extracted. The NHLBI study quality assessment tools and the JBI critical appraisal checklist were used to assess the quality of included studies.

Results

A total of 107 articles with 128 studies were included. Drugs interactions were revealed in calcium and iron supplements, proton pump inhibitors, bile acid sequestrants, phosphate binders, sex hormones, anticonvulsants and other drugs. Some food and beverage could also induce malabsorption. Proposed mechanisms included direct complexing, alkalization, alteration of serum thyroxine-binding globulin levels and acceleration of levothyroxine catabolism via deiodination. Dose adjustment, administration separation and discontinuation of interfering substances can eliminate the interactions. Liquid solutions and soft-gel capsules could eliminate the malabsorption due to chelation and alkalization. The qualities of most included studies were moderate.

Conclusion

Lots of medications and food can impair the bioavailability of levothyroxine. Clinicians, patients and pharmaceutical companies should be aware of the possible interactions. Further well-designed studies are needed to provide more solid evidence on treatment and mechanisms.

Placement of Nasogastric Feeding Tube and Postinsertion Care Review

Insertion and postinsertion care of enteral nasogastric feeding tubes are common procedures in the United States, with more than 1.2 million temporary nasogastric feeding tubes inserted annually. Although there are some evidence-based practice guidelines and recommendations for care of these tubes, variation in practice still exists. Additional research is needed to determine the best methodology for insertion and confirmation of nasogastric feeding tubes. Routine competency and training on feeding tube insertion, enteral nutrition, and postinsertion care is crucial to prevent patient safety events. Variable results have been reported with different technologies; however, radiographic confirmation remains the criterion standard. It is important that health care institutions develop standardized procedures for insertion and confirmation on the basis of evidence-based practices to minimize risks and complications from temporary nasogastric feeding tubes.

An Overview on Different L-Thyroxine (l-T4) Formulations and Factors Potentially Influencing the Treatment of Congenital Hypothyroidism During the First 3 Years of Life

Congenital hypothyroidism (CH) is a relatively frequent congenital endocrine disorder, caused by defective production of thyroid hormones (THs) at birth. Because THs are essential for the development of normal neuronal networks, CH is also a common preventable cause of irreversible intellectual disability (ID) in children. Prolonged hypothyroidism, particularly during the THs-dependent processes of brain development in the first years of life, due to delays in diagnosis, inadequate timing and dosing of levothyroxine (l-thyroxine or l-T₄), the non-compliance of families, incorrect follow-up and the interference of foods, drugs and medications affecting the absorption of l-T₄, may be responsible for more severe ID. In this review we evaluate the main factors influencing levels of THs and the absorption of l-T₄ in order to provide a practical guide, based on the existing literature, to allow optimal follow-up for these patients.

Levothyroxine Interactions with Food and Dietary Supplements-A Systematic Review

Levothyroxine (l-thyroxine, l-T4) is a drug of choice for treating congenital and primary hypothyroidism. Although clinically significant interactions between l-T4 and food can alter the safety and efficacy of the treatment, they still seem to be generally underestimated by patients, physicians and pharmacists. This review aimed to investigate the effects of meals, beverages, and dietary supplements consumption on l-T4 pharmacokinetics and pharmacodynamics, to identify the most evident interactions, and to perform the recommendations for safe co-administering of l-T4 and food. A total of 121 studies were identified following a systematic literature search adhering to PRISMA guidelines. After full-text evaluation, 63 studies were included. The results proved that l-T4 ingestion in the morning and at bedtime are equally effective, and also that the co-administration of l-T4 with food depends on the drug formulation. We found limited evidence for l-T4 interactions with coffee, soy products, fiber, calcium or iron supplements, and enteral nutrition but interestingly they all resulted in decreased l-T4 absorption. The altered l-T4 efficacy when ingested with milk, juices, papaya, aluminium-containing preparations, and chromium supplements, as well as observed enhancement effect of vitamin C on l-T4 absorption, shall be further investigated in larger, well-designed studies. Novel formulations are likely to solve the problem of coffee, calcium and iron induced malabsorption of l-T4. Maintaining a proper time interval between l-T4 and food intake, especially for coffee and calcium, or iron supplements, provides another effective method of eliminating such interactions.

Oral Levothyroxine is an Effective Option for Myxedema Coma: A Single-Centre Experience

INTRODUCTION

Myxedema coma is an endocrine emergency with a very high mortality rate. As per the American Thyroid Association, initial thyroid hormone replacement for myxedema coma should be intravenous levothyroxine (LT4). However, in India, the availability of intravenous LT4 is limited. Often, crushed LT4 tablets are given through the enteral route when parenteral therapy is unavailable. No data or protocol is available for the administration of oral LT4 in myxedema coma. The aim of this study was to assess the effectiveness of oral LT4 in patients diagnosed with myxedema coma and to formulate a protocol for oral LT4 that can be used to guide the treatment of patients when intravenous LT4 is unavailable.

METHODS

This retrospective observational study included patients diagnosed with myxedema coma between January 2010 and December 2019. The diagnosis of myxedema coma was based on the diagnostic scoring system for myxedema coma proposed by Popoveniuc et al. [Endocr Pract. 2014 Aug;20(8):808-17]. Dosing of oral LT4 was decided as per our institutional protocol.

RESULTS

Fourteen patients (11 males and 3 females) with a median age of 67.5 years (range 11-82) with myxedema coma were included. All patients had central nervous system manifestations, and sepsis was the most common precipitating factor. The median myxedema score was 72.5 (normal ≤25), and the median length of hospital stay was 12 days (range 3-18). The oral LT4 regimen consisted of a loading dose of 300-500 μg, followed by taper over the next 3-5 days. With this regimen, 13 patients survived, and only 1 patient died.

CONCLUSION

Oral LT4 is an effective treatment option for myxedema coma when intravenous LT4 is unavailable.

Alternative routes of levothyroxine administration for hypothyroidism

PURPOSE OF REVIEW

The aim of the article is to present the basics of oral levothyroxine (LT4) absorption, reasons why patients may have persistently elevated serum thyroid stimulation hormone (TSH) levels, and alternative strategies for LT4 dosing.

RECENT FINDINGS

Although oral LT4 tablets are most commonly used for thyroid hormone replacement in patients with hypothyroidism, case studies report that liquid oral LT4, intravenous, intramuscular, and rectal administration of LT4 can successfully treat refractory hypothyroidism.

SUMMARY

Hypothyroidism is one of the most common endocrine disorders encountered by primary care physicians and endocrinologists. LT4 is one of the most widely prescribed medications in the world and it is the standard of care treatment for hypothyroidism. Generally, hypothyroid patients will be treated with LT4 tablets to be taken orally, and monitoring will occur with routine serum thyroid tests, including TSH concentrations. However, many patients fail to maintain serum TSH levels in the target range while managed on oral LT4 tablets. A subset of these patients would be considered to have poorly controlled hypothyroidism, sometimes termed refractory hypothyroidism. For these patients, optimization of ingestion routines and alternative formulations and routes of administration of LT4 can be considered, including oral liquid, intravenous, intramuscular, and even rectal formulations.

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.

Management of Endocrine Emergencies in the ICU

Endocrine emergencies are frequent in critically ill patients and may be the cause of admission or can be secondary to other critical illness. The ability to anticipate endocrine abnormalities such as adrenal excess or , hypothyroidism, can mitigate their duration and severity. Hyperglycemic crisis may trigger hospital and intensive care unit (ICU) admission and may be life threatening. Recognition and safe treatment of severe conditions such as acute adrenal insufficiency, thyroid crisis, and hypoglycemia and hyperglycemic crisis may be lifesaving. Electrolyte abnormalities such as hypercalcemia and hypocalcemia may have underlying endocrine causes, and may be treated differently with recognition of those disorders- electrolyte replacement alone may not be adequate for efficient resolution. Sodium disorders are common in the ICU and are generally related to altered water balance however may be related to pituitary abnormalities in selected patients, and recognition may improve treatment effectiveness and safety.

Factors Affecting Gastrointestinal Absorption of Levothyroxine: A Review

PURPOSE

Levothyroxine (LT4) is a drug with a narrow therapeutic index, applied in small amounts (micrograms), which makes interactions in the absorption phase clinically significant. The main aim of this article was to review and present the latest information on factors that affect the gastrointestinal absorption of this drug.

METHODS

Relevant data were collected by using the MEDLINE, PubMed, EMBASE, Web of Science, Science Direct, and Scopus databases with the key words levothyroxine and absorption. Searches were not limited to specific publication types, study designs, dates, or languages. The reports were highly variable in the amount of information provided regarding study design and methods. Because of the heterogeneity of studies, no statistical analysis was performed.

FINDINGS

Many gastrointestinal disorders, such as celiac disease, atrophic gastritis, lactose intolerance, and Helicobacter pylori infection, may impede the absorption of levothyroxine. During treatment of these disorders, it is necessary to monitor serum thyroid-stimulating hormone and free T4 values to reduce the risk of developing iatrogenic hyperthyroidism. Soybeans and coffee have the greatest impact on the reduction of absorption, whereas vitamin C has the ability to increase it. Conversely, the effect of dietary fiber on the absorption of LT4 is not yet fully understood; further research is needed on this topic. A decrease in the absorption of LT4 is established and clinically significant when administered concomitantly with cholestyramine, colesevelam, lanthanum, calcium carbonate, calcium citrate, calcium acetate, iron sulfate, ciprofloxacin, aluminum hydroxide, sevelamer, or proton pump inhibitors. This effect should be taken into consideration when prescribing these drugs concomitantly with LT4. The effects of Giardia lamblia infection and the influence of orlistat, polystyrene sulfonate, raloxifene, and simethicone on absorption of LT4 have been poorly documented. For bariatric surgery, sucralfate and H₂-antagonist interactions are not well founded or contradictory evidence is available regarding their existence; additional research should be conducted.

IMPLICATIONS

The majority of the interactions are clinically significant. They are based on the LT4 adsorption on interfering substances in the digestive tract, as well as a consequently reduced amount of the drug available for absorption. These interactions can be avoided by separating the administration of LT4 and the interfering substance.

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.

Comparison between liquid and tablet levothyroxine formulations in patients treated through enteral feeding tube

BACKGROUND

The majority of clinicians suggest that enteral feedings should be held 1-2 h prior to and after L-T4 administration despite lack of data for continuous enteral nutrition.

AIM

The aim of this study was to: (1) compare the thyroid hormonal profile in patients submitted to L-T4 treatment in tablets or liquid formulation with an enteral feeding tube; (2) evaluate the nursing compliance with the two different formulations.

SUBJECTS AND METHODS

20 euthyroid patients submitted to total laryngectomy and thyroidectomy consecutively started L-T4 treatment in tablets (Group T) or in liquid formulation (Group L) with enteral feeding tube the day after surgery. Tablets were crushed before administration and enteral feeding was stopped for 30 min before and after L-T4 treatment, whereas liquid formulation was placed into the nasoenteric tube immediately. A questionnaire about the preparation and administration of thyroxine replacement therapy was given to the nurses.

RESULTS

No difference of TSH, fT4 and fT3 before and after L-T4 treatment was observed among patients of Group L. A slightly serum TSH increase was observed in Group T, but not reaching statistical significance (2.50 ± 1.18 vs 2.94 ± 1.22 mUI/L), whereas no difference in fT4 and fT3 levels was found. Preparation and administration of liquid L-T4 was considered excellent by 12/13 nurses, whereas tablet formulation was considered poor by 10/13.

CONCLUSIONS

Our data showed that liquid L-T4 formulation can be administered directly through feeding tube with no need for an empty stomach, with a significant improvement in therapy preparation and administration by nurses.

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.