Sublingual tacrolimus as an alternative to oral administration for solid organ transplant recipients

Immunosuppression in solid organ-transplant recipients and impact on nutrition support

A key component to nutrition support is to consider immunosuppressive agents, the interaction with nutrients, and how the side effects of the medications influence nutrition support. The immunosuppression of the solid organ-transplant recipient involves the individualized titration of multiple therapeutic agents to prevent allorecognition and, thus, rejection of the transplanted organ. Induction immunosuppression includes the agents used at the time of transplant to prevent early rejection. Maintenance immunosuppression typically consists of oral medications taken for life. Regular therapeutic monitoring of immunosuppression is necessary to balance the risk of rejection with that of infections and malignancy. In the acute-care setting, multidisciplinary collaboration, including pharmacy and nutrition, is needed to optimize the route of administration, titration, and side effects of immunosuppression. Long-term nutrition management after transplant is also vital to prevent exacerbating adverse effects of immunosuppressive therapies, including diabetes mellitus, hypertension, dyslipidemia, obesity, and bone loss. This review summarizes common immunosuppressive agents currently utilized in solid organ-transplant recipients and factors that may influence decisions on nutrition support.

Novel drug delivery strategies for antidepressant active ingredients from natural medicinal plants: the state of the art

Depression is a severe mental disorder among public health issues. Researchers in the field of mental health and clinical psychiatrists have long been faced with difficulties in slow treatment cycles, high recurrence rates, and lagging efficacy. These obstacles have forced us to seek more advanced and effective treatments. Research has shown that novel drug delivery strategies for natural medicinal plants can effectively improve the utilization efficiency of the active molecules in these plants and therefore improve their efficacy. Currently, with the development of treatment technologies and the constant updating of novel drug delivery strategies, the addition of natural medicinal antidepressant therapy has given new significance to the study of depression treatment against the background of novel drug delivery systems. Based on this, this review comprehensively evaluates and analyses the research progress in novel drug delivery systems, including nanodrug delivery technology, in intervention research strategies for neurological diseases from the perspective of natural medicines for depression treatment. This provided a new theoretical foundation for the development and application of novel drug delivery strategies and drug delivery technologies in basic and clinical drug research fields.

Population pharmacokinetics of sublingually administered tacrolimus in infants and young children with liver transplantation

AIMS

Pharmacokinetics of tacrolimus after sublingual administration is not characterized in paediatric liver transplant patients. Therefore, we aimed to develop a population pharmacokinetic model of sublingually administered tacrolimus in patients who cannot swallow the capsules due to their age, sedation status and/or mechanical ventilation during the first weeks post-transplantation.

METHODS

Demographic, clinical and pharmacological variables, including tacrolimus whole blood concentrations obtained from therapeutic drug monitoring and data from dense-sampling pharmacokinetic profiles, were recorded in 26 paediatric patients with biliary atresia who underwent liver transplantation between 2016 and 2021. Population pharmacokinetic analysis was performed with NONMEM v7.4.

RESULTS

Disposition of tacrolimus was best characterized by a 2-compartment model with clearance achieving half of the maximum elimination capacity (CL_MAX  = 4.1 L/h) at 4.6 days post-transplantation (T₅₀ ). Compared to sedated patients, nonsedated status showed an increased first-order absorption rate constant (1.1 vs. 0.1 h^-1 ) and a 24% reduction in bioavailability (F_NS ) at 14 days post-transplant. The model was able to explain the oral absorption pattern in nonsedated patients as the result of gut bioavailability (0.9) and hepatic extraction ratio, with the latter being responsible for first-pass effects. Estimates of interindividual variability remained moderate (25.9% for the gut bioavailability) to high (79.8% for the apparent volume of distribution of the central compartment, and 101% for T₅₀ ).

CONCLUSION

A population pharmacokinetic model of sublingually administered tacrolimus in paediatric patients was developed to characterize different absorption mechanisms. Once the model is externally validated, the effect of post-transplant time on clearance and the sedation status may be considered in routine dosing management.

A review of the rationale for the testing of the calcineurin inhibitor tacrolimus for post-ERCP pancreatitis prevention

Endoscopic retrograde cholangiopancreatography (ERCP) is commonly performed for the management of pancreaticobiliary disorders. The most troublesome ERCP-associated adverse event is post-ERCP pancreatitis (PEP), which occurs in up to 15% of all patients undergoing ERCP. A substantial body of preclinical data support a mechanistic rationale for calcineurin inhibitors in preventing PEP. The findings are coupled with recent clinical data suggesting lower rates of PEP in patients who concurrently use the calcineurin inhibitor tacrolimus (e.g., solid organ transplant recipients). In this review, we will firstly summarize data in support of testing the use of tacrolimus for PEP prophylaxis, either in combination with rectal indomethacin or by itself. Secondly, we propose that administering tacrolimus through the rectal route could be favorable for PEP prophylaxis over other routes of administration.

A Comprehensive Review of Calcineurin Inhibitors Used for Immunosuppression in Cardiac Transplantation

Calcineurin inhibitors (CNIs) have been the foundation of immunosuppression in solid organ transplantation since the 1980s. Cyclosporine A (CSA), the first in class, was identified as the metabolite of the soil fungus Tolypocladium inflatum Gams as part of a larger program of screening for naturally occurring fungal metabolites with biologic activity in the 1970s. Significant immunosuppressive effects were discovered and consequently CSA was trialed as an immunosuppressant in renal transplantation. This initial success led to its widespread study and adoption in solid organ transplantation. This novel agent yielded significant improvements in both 1 year and longer-term allograft and patient survival. Subsequently, a similar and more potent CNI, tacrolimus was developed. Today, it is the principal CNI used for prevention of allograft rejection. Like all other immunosuppressives, the benefits of CNIs are counterbalanced by side effects and complications resulting from drug toxicity. This chapter comprehensively reviews the clinical use of CNIs in cardiac transplantation.

Immunosuppressive effect of PLGA-FK506-NPs in treatment of acute cardiac rejection via topical subcutaneous injection

FK506, a first-line immunosuppressant, is routinely administered orally and intravenously to inhibit activation and proliferation of T cells after heart transplantation (HT). Current administration route is not conducive enough to exert its efficacy in lymphatic system. Herein, we proposed that subcutaneous (SC) administration of FK506-loaded nanoparticles (PLGA-FK506-NPs) would be valuable for treating acute rejection after HT. The biodistribution and pharmacokinetic study revealed that it could effectively deliver FK506 to the lymph nodes (LNs) due to their suitable particle size, especially in inguinal LNs. Subsequently, the therapeutic efficacy of PLGA-FK506-NPs on the HT model was evaluated using intravenous (IV), intragastric (IG), or SC injection. Histopathological analysis revealed that 80% of allografts exhibited only grade 1R rejection with negligible lymphocyte infiltration in the SC group. The IV group exhibited 40% 1R rejection with mild lymphocyte infiltration and 20% grade 3R that require further intervention, and the IG group exhibited grades 40% 3R rejection with more lymphocyte infiltration. Moreover, the infiltration of T cells and the secretion of IL-2 and IFN-γ were significantly reduced in the SC group compared with the IG or IV group. The mean survival time (MST) further revealed that 50% of grafts treated with PLGA-FK506-NPs via SC injection survived longer than IG and IV groups. Moreover, the MST of single-dose SC injection of PLGA-FK506-NPs demonstrated that it would effectively reduce the required dose for a similar therapeutic effect. Overall, these results indicate that SC administration of PLGA-FK506-NPs is a more effective route for chronic FK506 treatment.

The Aetiopathogenesis of Late Inflammatory Reactions (LIRs) After Soft Tissue Filler Use: A Systematic Review of the Literature

Background

Late inflammatory reactions (LIRs) are the most challenging complications after filler use. The immune system plays a prominent role in its etiology, albeit to an unknown extent. Bacterial contamination in situ has been hypothesized to be causative for LIRs. How this relates to the immunological processes involved is unknown. This article aims to provide an overview of immunological and bacterial factors involved in development of LIRs.

Methods

We undertook a systematic literature review focused on immunological factors and microbiota in relation to LIRs after filler use. This systematic review was performed in accordance with the PRISMA guidelines. PubMed, EMBASE and the Cochrane databases were searched from inception up to August 2019. Included studies were assessed for the following variables: subject characteristics, number of patients, primary indication for filler injection, implant type/amount and injection site, type of complication, follow-up or injection duration, study methods, type of antibiotics or medical therapies and outcomes related to microbiota and immunological factors.

Results

Data on immunological factors and bacterial contamination were retrieved from 21 included studies. Notably, the presence of histocytes, giant cells and Staphylococcus epidermidis within biopsies were often associated with LIRs.

Conclusion

This review provides a clear overview of the immunological factors associated with LIRs and provides a hypothetical immunological model for development of the disease. Furthermore, an overview of bacterial contamination and associations with LIRs has been provided. Follow-up research may result in clinical recommendations to prevent LIRs.

Level of Evidence III

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors-www.springer.com/00266..

Supplementary Information

The online version contains supplementary material available at 10.1007/s00266-021-02306-3.

Use of sublingual tacrolimus in adults undergoing hematopoietic cell transplant: A pilot study

INTRODUCTION

Orally administered tacrolimus is widely used in hematopoietic cell transplant patients, but multiple clinical situations may arise rendering oral administration infeasible. The undesirable sequelae of intravenous administration, including toxicity, challenges with administration and cost call for innovative solutions to conserve existing supply and optimize safety and efficacy of medication delivery. We sought to demonstrate feasibility of sublingual tacrolimus use and estimate a sublingual-to-oral (SL:PO) conversion ratio in the hematopoietic cell transplant setting.

METHODS

Ten adults undergoing allogeneic hematopoietic cell transplant received tacrolimus 0.04 mg/kg/dose twice daily. Initial doses were given via sublingual route and a steady state trough level was collected after 4 consecutive doses. Participants were then switched to oral tacrolimus, the dose adjusted for a goal trough 8-12ng/mL, and another steady state trough was drawn. Total daily dose was divided by trough concentration for each route to determine the dosing ratio of SL:PO.

RESULTS

Median trough level following sublingual administration was 11.3 ng/mL. Three of these were within goal, 3 were low (4.7-6.4 ng/mL) and 4 were elevated (15.9-18.6 ng/mL). Median SL:PO ratio was 1.02. In 5 participants the SL:PO ratio was <1 (range 0.57-0.94) and in 5 the ratio was ≥1 (range 1.10-1.92). No significant barriers or intolerance to sublingual tacrolimus use were noted.

CONCLUSIONS

Results demonstrate reliable absorption with sublingual tacrolimus use in patients undergoing hematopoietic cell transplant. Sublingual administration may allow for avoidance of the undesirable complications of IV tacrolimus, such as increased toxicities, required hospitalization for continuous infusion, risk of dose conversion and dilution errors and increased cost.Trial Registry name: Use of Sublingual Tacrolimus in Adult Blood and Marrow Transplant Patients, NCT04041219https://clinicaltrials.gov/ct2/show/NCT04041219?term=NCT04041219&draw=2&rank=1.

Considerations and controversies of pharmacologic management of the pediatric kidney transplant recipient

Pediatric kidney transplantation has experienced considerable growth and improvement in patient and allograft outcomes over the past 20 years, in part due to advancements in immunosuppressive regimens and management. Despite this progress, care for this unique population can be challenging due to limited pediatric transplant data and trials, intricacies related to differences in children and adolescents compared with their adult counterparts, and limitations to long-term survival facing all solid organ transplant populations. Immunosuppression and infection prevention practices vary from one pediatric transplant center to another and clinical controversies exist surrounding treatment and dosing. This review aims to summarize key aspects of pharmacologic management in this population and present pertinent data that describe the influence of practice to serve as a resource for practitioners caring for this unique specialty patient population. Additionally, this review highlights select controversies that exist within pediatric kidney transplantation.

Network pharmacology-based analysis of the role of tacrolimus in liver transplantation

Background

Tacrolimus is a powerful immunosuppressant and has been widely used in organ transplantation. In order to further explore the role of tacrolimus in liver transplantation, we conducted network pharmacology analysis.

Methods

GSE100155 was obtained from the GEO database, and the DEGs of liver transplantation were analyzed. The 2D structure of tacrolimus was obtained from the National Library of Medicine, and the pharmacophore model of tacrolimus was predicted using the online tool pharmmapper. Then a network of tacrolimus and target genes was constructed through network pharmacology, and visualization and GO enrichment analysis was performed through Cytoscape. In addition, we also analyzed the correlation between key genes and immune infiltrating cells. The data of GSE84908 was used to verify the changes of key gene expression levels after tacrolimus treatment.

Results

The results of network pharmacological analysis showed that tacrolimus had 43 target genes, and the GO enrichment results showed many potential functions. Further analysis found that there were 5 key target genes in DEGs, and these 5 genes were significantly down-regulated in liver transplant patients. Another important finding was that 5 genes were significantly related to some immune infiltrating cells. The results of the GSE84908 data analysis showed that after tacrolimus treatment, the expression of DAAM1 was significantly increased (p = 0.015).

Conclusion

Tacrolimus may inhibit the human immune response by affecting the expression of DAAM1 in liver transplant patients.

The hurdles of nanotoxicity in transplant nanomedicine

Nanomedicine has matured significantly in the past 20 years and a number of nanoformulated therapies are cleared by regulatory agencies for use across the globe. Transplant medicine is one area that has significantly benefited from the advancement of nanomedicine in recent times. However, while nanoparticle-based therapies have improved toxicological profiles of some drugs, there are still a number of aspects regarding the biocompatibility and toxicity of nanotherapies that require further research. The goal of this article is to review toxicological profiles of immunosuppressant therapies and their conversion into nanomedicine formulations as well as introduce future challenges associated with current in vitro and in vivo toxicological models.

Considerations for Medications Commonly Utilized in the Oncology Population in the Intensive Care Unit

An increasing number of oncologic patients are presenting to the intensive care unit with complications from both their chronic disease states and cancer therapies due to improved survival rates. The management of these patients is complex due to immunosuppression (from the malignancy and/or treatment), metabolic complications, and diverse medication regimens with the potential for significant drug-drug interactions and overlapping adverse effects. This chapter will provide clinicians with an overview of non-chemotherapy medications frequently encountered in the critically ill oncologic patient, with a focus on practical considerations.

Sublingual tacrolimus administration provides similar drug exposure to per-oral route employing lower doses in liver transplantation: a pilot study

BACKGROUND

Per-oral tacrolimus administration is not always practicable. Sublingual administration is a potential alternative, but its feasibility and effectiveness compared with oral route has not been established.

AIM

To compare tacrolimus drug exposure after sublingual and oral administration in liver transplant recipients.

METHODS

Experimental, open-label, non-randomised, cross-over study. Tacrolimus exposure was evaluated in 32 liver transplant recipients receiving oral administration. 12 h tacrolimus area-under-the-curve (AUC_{0-12 h} ) was calculated using tacrolimus blood concentrations at 0-0.5-1-2-4-6-8-12 hrs post-dose. Recipients were switched to sublingual administration, and dose was adjusted to reach similar trough levels, new AUC_{0-12 h} was calculated. Correlation between AUC_{0-12 h} and trough levels was determined for both oral and sublingual phases.

RESULTS

Similar trough levels were accomplished with oral and sublingual administration (6.68 ± 2 ng/mL vs. 6.62 ± 1.9 ng/mL (P = 0.8)). Although concentration 2 h post dose was higher in oral phase (15.36 ± 7.14 vs. 13.18 ± 5.64, P = 0.015), AUC_{0-12 h} was similar in both phases (116.6 ± 34.6 vs. 111.5 ± 36.93 ng/mL_* h, P = 0.19). Daily dose of tacrolimus required in sublingual phase was 37% lower than that used in oral phase (P < 0.0001), suggesting significantly increased bioavailability of tacrolimus when employing sublingual route. Good correlation between AUC_{0-12 h} and trough levels was observed in sublingual phase (r² = 0.74). Twenty-two recipients were maintained on sublingual administration after the end of study (mean follow-up: 18.7 ± 5.8 months). No difference in liver function tests or rejection rates was found during follow-up period.

CONCLUSIONS

Sublingual administration of tacrolimus is feasible and provides similar drug exposure compared with oral administration. In our study, at long-term follow-up, sublingual administration was not associated with liver transplant rejection.

Immunosuppression in Solid-Organ Transplantation: Essentials and Practical Tips

A multidisciplinary team approach is essential for successful management of patients with solid-organ transplant. Transplant nursing encompasses care and support of transplant recipients as well as caregivers and organ donors through all phases of transplantation, from pretransplant evaluation to posttransplant recovery and maintenance. The field of solid-organ transplantation has advanced rapidly, and new treatments continue to emerge. Nurses who are responsible for the care of transplant recipients should have a knowledge base in transplant immunology and pharmacology. This review discusses mechanism of action, indication, side effects, and drug interactions of commonly used immunosuppressive medications in solid-organ transplantation. Nonoral routes of drug administration, therapeutic drug monitoring, and patient monitoring strategies are also included as practical tips for bedside nurses who are responsible for delivery of direct patient care and education of patients and their caregivers. This review focuses on the following medications: antithymocyte globulins, basiliximab, alemtuzumab, corticosteroids, tacrolimus, cyclosporine, azathioprine, mycophenolate mofetil/mycophenolate sodium, sirolimus, everolimus, belatacept, intravenous immunoglobulin, and rituximab.