Evaluation of Appropriate Blood Level in Continuous Intravenous Infusion From Trough Concentrations After Oral Administration Based on Area Under Trough Level in Tacrolimus and Cyclosporine Therapy

Comparison of intermittent intravenous tacrolimus to continuous tacrolimus in adult allogeneic stem cell transplant recipients

Introduction: Initial continuous intravenous (CIV) tacrolimus (0.03 mg/kg/day based on ideal body weight [IBW]) has been favored for graft versus host disease (GVHD) prevention in allogeneic stem cell transplant patients due to the consistent, steady-state degree of immunosuppression; however, this method poses many logistical challenges. We implemented intermittent (IIV) tacrolimus at a starting dose of 0.015 mg/kg IBW twice daily over 4 h. To our knowledge this is the first retrospective comparison of CIV to IIV tacrolimus. Objectives: The primary objective was to evaluate the safety of IIV tacrolimus in comparison to CIV with respect to nephrotoxicity and neurotoxicity. The secondary objectives were to compare the incidence of grade II-IV acute GVHD (aGVHD) and chronic GVHD (cGVHD) at day +180, outcomes including relapse and overall survival, cell engraftment, and reactivation of cytomegalovirus and Epstein-Barr virus. Methods: This retrospective, single-center review evaluated adults who received an allogeneic stem cell transplant patients between January 1, 2020, and December 31, 2022. Results: Fifty-one unique patients were eligible for evaluation - 28 in the IIV cohort and 23 in the CIV group. The number of patients who developed nephrotoxicity and neurotoxicity were comparable between groups with no significant differences noted. No severe neurotoxicity was identified in either population. Secondary objectives revealed no significant difference in GVHD incidence or survival outcomes. Conclusion: IIV tacrolimus is comparable to CIV in terms of safety while also maintaining similar outcomes at day +180. IIV is a safe and feasible alternative to CIV in adult allogeneic stem cell transplant recipients.

Comparison of continuous versus intermittent infusion cyclosporine and impact on transplant related outcomes in allogeneic transplant recipients

INTRODUCTION

Continuous infusion (CIVI) cyclosporine (CsA) is an alternative for allograft recipients intolerant of twice daily infusions (TDI). The importance of achieving therapeutic levels of CsA early after allogeneic HCT has been demonstrated in previous studies. Our study evaluated the incidence of acute graft versus host disease (GVHD) and survival among patients receiving CIVI vs. TDI CsA during their first allogeneic HCT.

METHODS

A retrospective study of adult patients undergoing first allogeneic HCT at the University of Minnesota Medical Center between 2011 and 2017. Patients were grouped according to the administration method. The primary outcome was the occurrence of acute grade II-IV GVHD by day +180. Secondary outcomes included the 1-year incidence of chronic GVHD, relapse, and overall survival.

RESULTS

42 patients intolerant of TDI CsA received CsA via CIVI for >48 hours for a median of 9 days (range, 3-32 days). CsA concentrations were similar between groups. We found no difference between the rates of grade II-IV acute (45% vs 53%, p = 0.59) or chronic (17% vs 30%, p = 0.20) GVHD or overall survival (57% vs 67%, p = 0.10). Subgroup analysis of patients that received myeloablative conditioning or umbilical cord blood did not reveal significant differences in GVHD or overall survival. Cumulative incidence of relapse was higher among the continuous infusion group (39% vs. 23%, p < 0.01).

CONCLUSION

Due to the finding of increased risk of relapse, cyclosporine should be administered as traditional twice daily infusion unless necessary. A prospective clinical trial is needed to confirm these results.

Clinical Factors Affecting the Dose Conversion Ratio from Intravenous to Oral Tacrolimus Formulation among Pediatric Hematopoietic Stem Cell Transplantation Recipients

BACKGROUND

Tacrolimus is converted from intravenous to oral formulation for the prophylaxis of graft-versus-host disease when patients can tolerate oral intake and graft-versus-host disease is under control. Oral tacrolimus formulation presents poor bioavailability with intraindividual and interindividual variations; however, some factors affecting its blood concentration among pediatric hematopoietic stem cell transplantation (HCT) recipients are still unclear. This study aimed to identify the clinical factors affecting tacrolimus blood concentrations after switching its formulation.

METHODS

Changes in the blood concentration/dose ratio (C/D) of tacrolimus in pediatric HCT recipients were analyzed after the switching of tacrolimus from intravenous to oral formulation. Clinical records of 57 pediatric patients who underwent allogenic HCT from January 2006 to April 2019 in our institute were retrospectively reviewed. The C/D of tacrolimus before discontinuation of intravenous infusion (C/Div) was compared with the tacrolimus trough level within 10 days after the initiation of oral administration (C/Dpo). Multiple linear regression analysis was performed to identify factors affecting (C/Dpo)/(C/Div).

RESULTS

The constant coefficient of (C/Dpo)/(C/Div) was 0.1692 [95% confidence interval (CI), 0.137-0.2011]. The concomitant use of voriconazole or itraconazole and female sex were significant variables with a beta coefficient of 0.0974 (95% CI, 0.062-0.133) and -0.0373 (95% CI, -0.072 to -0.002), respectively.

CONCLUSIONS

After switching of tacrolimus formulation, pediatric HCT recipients might need oral tacrolimus dose that is 5-6 and 3.5-4.5 times the intravenous dose to maintain tacrolimus blood concentrations and area under the concentration-time curve, respectively. With the concomitant use of voriconazole or itraconazole, an oral tacrolimus dose of 4-5 times the intravenous dose seemed appropriate to maintain blood tacrolimus concentration.

Tacrolimus blood concentration increase depends on administration route when combined with voriconazole in pediatric stem cell transplant recipients

BACKGROUND

Understanding of TAC pharmacokinetics is required to avoid both overdosing and underdosing. VRCZ is known to increase the TAC blood concentration by inhibiting CYP3A4; however, detailed, practical information on pediatric cases is still scarce. Herein, we investigated the association between the TAC blood concentration and dosage focusing on the administration route and concomitant use of VRCZ in children.

METHODS

In total, 38 children who received TAC during stem cell transplantation at our hospital between January 2013 and April 2018 were included. The ratio of the TAC blood concentration (ng/mL) to dosage (mg/kg/day) (C/D) was calculated at the last continuous intravenous infusion (C/Div) and after switching to oral administration (C/Dpo).

RESULTS

Patients with VRCZ (n = 14) showed a higher C/D regardless of administration route (median C/Div: with VRCZ/without VRCZ = 832/643, median C/Dpo: with VRCZ/without VRCZ = 339/45). Additionally, the (C/Div)/(C/Dpo) was about one-fourth in cases with VRCZ; the median (C/Div)/(C/Dpo) was 3.3 for cases with VRCZ and 13.5 for cases without VRCZ. Interestingly, the increase in the TAC blood concentration due to VRCZ was higher when TAC was administered orally, especially in adolescent patients.

CONCLUSIONS

To obtain an optimal TAC blood concentration, dose adjustment based on multiple factors, such as administration route, concomitant use of VRCZ, and age, is required.

Immunosuppressive drugs and the gastrointestinal tract in renal transplant patients. Transplant Rev (Orlando). 2019;33:55-63. [PMID: 30473173 DOI: 10.1016/j.trre.2018.11.001]

Gastrointestinal (GI) discomfort is common after renal transplantation and can be caused by the use of various immunosuppressive drugs. GI symptoms affect the quality of life, lead to an impaired graft survival and an increased mortality. Moreover, diseases and disturbances of the GI tract also affect the pharmacokinetics of immunosuppressive drugs. This review addresses the interaction between immunosuppressive agents and GI disorders. The GI tract is involved in the metabolism of several immunosuppressive drugs. Calcineurin inhibitors, mTor inhibitors, and corticosteroids are subjected to metabolism by the intestinal cytochrome P450 (CYP3A) and by the drug efflux pump ABCB1. Mycophenolate is partly metabolized in the stomach and intestine and undergoes enterohepatic recirculation. Gastrointestinal disturbances can lead to a modified exposure to immunosuppressive drugs. In the first and second part of this review, we focus on the role of the GI tract in the pharmacokinetics of the immunosuppressive drugs and how to adjust immunosuppressive therapy in patients with vomiting, need for tube feeding, delayed gastric emptying, intestinal resection, and diarrhea. In the third part, we review the GI adverse effects of the various immunosuppressive drugs, with special attention for diarrhea and dyspepsia. Finally, we discuss the effects of drugs used for relief of GI complaints on the exposure to immunosuppressive agents.

Drug-drug interactions between antiretroviral and immunosuppressive agents in HIV-infected patients after solid organ transplantation: a review

Since the introduction of combination antiretroviral therapy (cART) resulting in the prolonged survival of HIV-infected patients, HIV infection is no longer considered to be a contraindication for solid organ transplantation (SOT). The combined management of antiretroviral and immunosuppressive therapy proved to be extremely challenging, as witnessed by high rates of allograft rejection and drug toxicity, but the profound drug-drug interactions between immunosuppressants and cART, especially protease inhibitors (PIs) also play an important role. Caution and frequent drug level monitoring of calcineurin inhibitors, such as tacrolimus are necessary when PIs are (re)introduced or withdrawn in HIV-infected recipients. Furthermore, the pharmacokinetics of glucocorticoids and mTOR inhibitors are seriously affected by PIs. With the introduction of integrase inhibitors, CCR5-antagonists and fusion inhibitors which cause significantly less pharmacokinetic interactions, have minor overlapping toxicity, and offer the advantage of pharmacodynamic synergy, it is time to revaluate what may be considered the optimal antiretroviral regimen in SOT recipients. In this review we provide a brief overview of the recent success of SOT in the HIV population, and an update on the pharmacokinetic and pharmacodynamic interactions between currently available cART and immunosuppressants in HIV-infected patients, who underwent SOT.

Coadministration of cyclosporin a with prednisolone in acute interstitial pneumonia complicating polymyositis/dermatomyositis

Objective

To investigate clinical effectiveness of prednisolone (PSL) and cyclosporin A (CyA), particularly continuous intravenous administration of the latter, in patients with interstitial pneumonia (IP) associated with polymyositis/dermatomyositis (PM/DM).

Methods

We reviewed the clinical findings and therapeutic outcomes of patients with PM/DM who had received PSL and CyA (PSL + CyA, n = 21 for DM and 2 for PM) or the former alone (n = 12 for DM and 7 for PM). All patients receiving PSL + CyA had active IP.

Results

Fifteen of the 21 DM patients receiving PSL + CyA showed favorable therapeutic outcomes of IP (recovery group), while the remaining 6 died of respiratory failure (death group). Before treatment PaO₂ in room air and %VC were significantly lower, and the total CT score was significantly higher in the death group than in the recovery one. Continuous intravenous administration of CyA was performed in 6 patients for severe IP requiring oxygen therapy, and of these 2 showed complete recovery from it.

Conclusions

Coadministration of PSL and CyA, particularly continuous intravenous infusion of the latter, from the early phase of illness may be a potent therapeutic option for PM/DM patients with decreases in PaO₂ and %VC and/or a high total CT score suggestive of a poor prognosis.

Decreased incidence of acute graft-versus-host disease by continuous infusion of cyclosporine with a higher target blood level

Cyclosporine A (CsA) is the mainstay of pharmacologic prevention of acute graft-versus-host disease (GVHD). We previously reported that continuous infusion of CsA with a target blood level between 250 and 400 ng/ml significantly increased the incidence of acute GVHD compared to twice-daily infusion with a target trough level between 150 and 300 ng/ml. Thus, we raised the target level of CsA continuous infusion to 450-550 ng/ml. We treated 33 patients with the higher target level (CsA500) and compared the efficacy and toxicity with those in the 33 historical control patients (CsA300 group). Other transplantation procedures were not changed. The patients' characteristics were equivalent. The average CsA concentration was adjusted around 500 ng/ml and the actual daily dose was maintained at the initial dose (CsA 3mg/kg/day). Toxicities were equivalently observed among the two groups. The incidence of grades II-IV acute GVHD was significantly lower in the CsA500 group (27 vs. 52%, P = 0.033). The target level of CsA was identified as an independent significant risk factor for grades II-IV acute GVHD (P = 0.039), adjusted for the presence of HLA mismatch. The incidence of chronic GVHD was also decreased in the CsA500 group (47 vs. 73%, P = 0.016). We conclude that the toxicity of the continuous CsA infusion with a target level of 450-550 ng/ml is acceptable and the efficacy to prevent acute GVHD is significant. A larger comparative study is warranted to confirm these findings.