A pilot study on sublingual administration of tacrolimus

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.

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.

Sublingual administration improves systemic exposure of tacrolimus in kidney transplant recipients: comparison with oral administration

BACKGROUND

Tacrolimus (TCR) is an immunosuppressive drug used by oral administration. Intravenous (IV) TCR administration is required under conditions of gastrointestinal diseases or abdominal surgery at the onset of paralytic ileus. The infusion formulation needs a large dilution and therefore a careful technical management during continuous infusion by 24 h and may determine anaphylaxis, cardiac arrhythmia, QT prolongation and torsades de pointes. Sublingual (SL) TCR administration was suggested as an alternative route.

DESIGN

The aim of this study was to compare in the same kidney transplanted patients the TCR pharmacokinetic profiles by both the routes coupled with the pharmacoeconomic analysis. The study enrolled eight subjects undergoing renal transplantation and treated with TCR and methylprednisolone. TCR was administered by oral route at the scheduled dosage while the 50% of oral dosage was used by SL route, taking into account the absence of liver first pass.

RESULTS

Except for AUC, which resulted significantly increased after oral administration, all exposure parameters were not significantly different between the two routes of administration. Analysis of dose-adjusted exposure parameters showed significant increases in AUC and Cmin after SL administration confirming a better bioavailability of the SL route compared with oral route. Cost saving was obtained using the SL rather than the IV route of TCR delivery.

CONCLUSION

When oral administration of TCR is not advised, SL delivery represents an attractive option to IV administration.

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

PURPOSE

Available data regarding sublingual tacrolimus were analyzed to provide recommendations for solid organ transplant recipients.

SUMMARY

Tacrolimus is an immunosuppressive agent with a narrow therapeutic range that is commonly used in solid organ transplantation. Achieving and maintaining appropriate tacrolimus exposure are critical for preventing rejection and minimizing toxicity. A variety of clinical situations requiring nonoral medication delivery arise, presenting the need for reliable alternative routes of tacrolimus administration. A review of the currently available literature revealed nine reports of sublingual tacrolimus use in human subjects. Seven reported that sublingual administration could achieve comparable tacrolimus trough concentrations to oral administration, but none investigated the correlation between tacrolimus trough concentration and exposure. One study of lung transplant recipients found that approximately 50% of the oral dose was needed to obtain therapeutic trough concentrations when converted to sublingual administration. Another study of patients with end-stage renal disease identified a similar sublingual:oral dosing ratio of 1:2. When converted from oral tacrolimus in combination with clotrimazole to sublingual administration, the sublingual:oral dosing ratio was 1:1.

CONCLUSION

In addition to enteral tube and i.v. tacrolimus dosing, sublingual administration may be considered for short-term use in patients who are unable to receive medications orally. Based on the available data, it is reasonable to initiate sublingual tacrolimus at 50% of the current or anticipated oral dose in the absence of interacting medications. Dosing must be individualized, taking into consideration concomitant interacting medications, and adjusted to target levels based on therapeutic drug monitoring.

[Bariatric surgery, stomas and other digestive tract reductions: Insufficient data and recommendations to adapt medicines regimens in therapeutic practice]

Surgery modifying digestive tract may alter drugs pharmacokinetics. To maintain concentrations of active substance in their therapeutic ranges, a dosage adjustment or change of drug may be necessary. This is particularly important when no pharmacological or pharmacodynamic parameter reflecting the medication effectiveness is easily measurable. Our objective was to gather the information and documentary tools that can guide prescription in these patients with rearranged digestive tract. We searched information on the documentary portals of French agencies, on gray literature, on MEDLINE and in the summaries product characteristics. No information was found on the website of French agencies, sparse data were identified in gray literature. Some document are discordant, most are imprecise. One hundred and ten studies or case reports referenced on MEDLINE describe 79 medications pharmacokinetics after gastrointestinal surgery. Four are not available in France. Six literature reviews were found. Four summaries of product characteristics provided information related to drug absorption. No documentary tool adapted to clinical routine exists. This unsatisfactory situation is a barrier to optimal patients care. Information is available. It is however necessary to gather under an ergonomic shape adapted to clinical routine, bringing the surgery type, pharmacokinetic changes induced and what to do about the dose adjustment.

Rectal and sublingual administration of tacrolimus: a single-dose pharmacokinetic study in healthy volunteers

AIMS

The immunosuppressant tacrolimus is usually administered orally. When this is not feasible, other routes of administration may be useful. Previous research suggested that tacrolimus may be applied sublingually or rectally. Pharmacokinetic data are sparse. The aim of this study was to investigate and compare the pharmacokinetics of these alternative formulations with orally administered tacrolimus.

METHODS

Three single, fixed-dose formulations of tacrolimus were administered in a random sequence in 18 healthy subjects, using a cross-over study design. For sublingual administration, 3 mg of powder obtained from oral capsules was applied under the tongue for a period of 15 min without swallowing, with mouth rinsing afterwards. For rectal administration, a suppository containing 15 mg of the oral powder was used. Oral administration consisted of 7 mg of instant-release tacrolimus capsules (Prograf). Main pharmacokinetic outcome parameters were compared by anova.

RESULTS

Sublingual administration showed no clinically significant exposure, contrary to rectal administration, where all subjects had clinically relevant exposure, with a lower relative bioavailability (78%), a lower maximal blood concentration and a later time of maximal blood concentration compared with oral administration.

CONCLUSIONS

Sublingual administration of a single dose of tacrolimus does not result in systemic exposure if care is taken not to swallow saliva and to rinse the oral cavity afterwards. Rectal administration of tacrolimus results in clinically relevant systemic exposure and might represent an alternative formulation in case oral administration is not feasible. When used as a topical agent, systemic side-effects should be considered.

Advances in immunosuppression after lung transplantation

Immunosuppression in transplantation has experienced changes in recent years as a result of the introduction of new drugs that act upon the different pathways of the host immune response with the purpose of securing more individualized immune suppression, with fewer side effects. Although following in the steps of other solid organ transplant modalities, lung transplantation, because of its special characteristics, has not yielded similar middle- and long-term results. Improved understanding of the underlying rejection mechanisms, the pharmacodynamic control of drugs, new administration routes designed to reduce the side effects, and new drug substances or immune modulating processes will all contribute to improve the expectations associated to lung transplantation in the near future.

Use of sublingual tacrolimus in lung transplant recipients

BACKGROUND

In lung transplant recipients (LTRs), tacrolimus is often utilized as a core component of immunosuppressive regimens. Although tacrolimus can be delivered orally or intravenously, oral tacrolimus is associated with fewer adverse effects. Various reports have suggested that sublingual tacrolimus may be used as an alternative to oral tacrolimus; however, information regarding converting between routes is limited. We aimed to identify a dose conversion ratio between oral and sublingual tacrolimus in LTRs.

METHODS

We identified adult LTRs at the University of California, San Francisco, who transitioned between oral and sublingual tacrolimus between 2005 and 2010 (n = 34). For tacrolimus, we obtained steady-state blood concentrations and total daily doses before and after the route conversion. Blood concentrations divided by daily doses were calculated for each route. The conversion ratio was then defined as: (blood concentration(sublingual)/daily dose(sublingual))/(blood concentration(oral)/daily dose(oral)). This ratio was tested in inpatient vs outpatient settings and in the presence of impaired gastric emptying. Adverse effects, including nephrotoxicity, hepatotoxicity and anaphylaxis, were evaluated.

RESULTS

The conversion ratio of sublingual to oral tacrolimus was 0.46 ± 0.20 (mean ± SD). The ratio was not associated with hospital setting (p = 0.82) or with impaired gastric emptying (p = 0.31). When comparing sublingual to oral tacrolimus administration, there were no differences in serum creatinine, liver function tests or anaphylaxis.

CONCLUSIONS

Tacrolimus administered sublingually at approximately half of the oral dose achieves therapeutic blood concentrations and is safe in LTRs. Delivery via the sublingual route using this conversion ratio may aid clinicians in maintaining therapeutic tacrolimus blood concentrations while avoiding the need for intravenous administration.

Conventional and novel approaches to immunosuppression

Immunosuppressive therapy has contributed significantly to improved survival after solid organ transplantation. Nevertheless, treatment-related adverse events and persistently high risk of chronic graft rejection remain major obstacles to long-term survival after lung transplantation. The development of new agents, refinements in techniques to monitor immunosuppression, and enhanced understanding of transplant immunobiology are essential for further improvements in outcome. In this article, conventional immunosuppressive regimens, novel approaches to preventing graft rejection, and investigational agents for solid organ transplantation are reviewed.