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Target Trough Levels (target + trough_level)
Selected AbstractsSafety and Efficacy of Raltegravir in HIV-Infected Transplant Patients Cotreated with Immunosuppressive DrugsAMERICAN JOURNAL OF TRANSPLANTATION, Issue 8 2009L. Tricot Solid organ transplantations (SOT) are performed successfully in selected HIV-infected patients. However, multiple and reciprocal drug,drug interactions are observed between antiretroviral (ARV) drugs and calcineurin inhibitors (CNIs) through CYP450 metabolization. Raltegravir (RAL), a novel HIV-1 integrase inhibitor, is not a substrate of CYP450 enzymes. We retrospectively reviewed the outcomes of 13 HIV-infected transplant patients treated by an RAL + two nucleosidic reverse transcriptase inhibitor (NRTI) regimen, in terms of tolerability, ARV efficacy (plasma viral load, CD4 cell count), drug interactions, RAL pharmacokinetics and transplant outcome. Thirteen patients with liver (n = 8) or kidney (n = 5) transplantation were included. RAL was initiated (400 mg BID) either at time of transplantation (n = 6), or after transplantation (n = 7). Median RAL trough concentration was 507 ng/mL (176,890), which is above the in vitro IC95 for wild type HIV-1 strains (15 ng/mL). Target trough levels of CNIs were promptly obtained with standard dosages of tacrolimus or cyclosporine. RAL tolerability was excellent. There was no episode of acute rejection. HIV infection remained controlled. After a median follow-up of 9 months (range: 6,14), all patients were alive with satisfactory graft function. The use of an RAL + two NRTI-based regimen is a good alternative in HIV-infected patients undergoing SOT. [source] Pharmacokinetics of factors IX, recombinant human activated factor VII and factor XIIIHAEMOPHILIA, Issue 2006M.-C. POON Summary., There is now a volume of literature on the pharmacokinetics (PK) of coagulation factor concentrates, although the majority is on factor VIII (FVIII) and factor IX (FIX). PK of FIX and FVIII are different with FIX having a larger volume of distribution (Vdss), higher elimination clearance (CL), longer mean resident time (MRT) and longer terminal half-life (T1/2,,). Factor IX in vivo recovery (IVR) is also much shorter possibly due to reversible binding of FIX to the endothelium and possibly to platelets. There is considerable FIX PK variability between products (particularly between plasma-derived FIX and recombinant FIX), and between individuals. Important inter-individual factors leading to PK variability include age and body weight because plasma volume as a fraction of body weight decreases with increasing weight and hence age. Thus, IVR increases with body weight and hence age and is consequently lower in children than in adults. Absolute Vdss and CL increase linearly with body weight and age in children and adolescents, becoming stable in adults with more stable weight. Inter-individual variability also likely applies to other clotting factors, particularly to recombinant activated FVII (rFVIIa) but likely also to the less well studied factor XIII (FXIII). The former is known to have an extremely short T1/2,,, large Vdss, high CL, short MRT, whereas the latter has an extremely long T1/2,,, large Vdss, short CL and long MRT. Both are discussed in this article. Understanding of PK of specific clotting factors in individual patients is important in order to make decisions regarding appropriate dosage and dosage intervals to treat patients, and to allow by means of computer modelling the determination of dosage to achieve target trough level at various dosing intervals for patients undergoing prophylaxis. [source] Evaluation of renal function in liver transplant recipients receiving daclizumab (Zenapax), mycophenolate mofetil, and a delayed, low-dose tacrolimus regimen vs. a standard-dose tacrolimus and mycophenolate mofetil regimen: A multicenter randomized clinical trialLIVER TRANSPLANTATION, Issue 9 2005Eric M. Yoshida Posttransplant chronic renal failure, secondary to calcineurin inhibitor agents, is emerging as a major problem in liver transplantation. We report a randomized clinical trial comparing daclizumab, delayed low-dose tacrolimus (target trough level 4-8 ng/mL, starting day 4-6), Investigational Arm (n = 72), to standard tacrolimus induction/maintenance dosing, Standard Arm (n = 76), with mycophenolate mofetil and tapering corticosteroids in both study arms. The end-points were renal function indicated by the Modification of Diet in Renal Disease (MDRD). There was no significant difference in patient survival (86.6% Investigational Arm vs. 92.9% Standard Arm; P = 0.21) or acute rejection (23.2% vs. 27.7%, respectively; P = 0.68). Statistically significant differences in median glomerular filtration rate (GFR) were found in favor of the Investigational Arm. With the CG equation, the GFR at the end of the first week was 110.7 vs. 89.6 mL/min (P = 0.019) without significant differences thereafter. With the MDRD, statistically significant differences extended to the first posttransplant month (86.8 vs. 70.1 mL/min/1.73 m2; P < 0.001) with and was seen at month 6 (75.4 vs. 69.5 mL/min/1.73 m2; P = 0.038). In conclusion, delayed low-dose tacrolimus, in combination with daclizumab and mycophenolate mofetil, preserves early renal function post,liver transplantation without the cost of increased acute rejection. (Liver Transpl 2005;11:1064,1072.) [source] Orthotopic liver transplantation using low-dose tacrolimus and sirolimusLIVER TRANSPLANTATION, Issue 8 2001Vivian C. McAlister MB Although sirolimus (SRL) binds the immunophilin FK506-binding protein-12 (FKBP-12) with greater avidity than tacrolimus (TAC), animal studies have shown that SRL and TAC act synergistically to prevent rejection. Dose-related toxicity is more often the cause of TAC discontinuation than rejection. We hypothesized that SRL would allow for a substantial reduction in the concomitant dose of TAC after liver transplantation to levels less than the threshold for toxicity. A series of 56 liver transplant recipients were administered a combination of SRL and TAC (target trough levels, 7 and 5 ng/mL, respectively). Planned weaning of steroids commenced after 3 months. Pharmacokinetic (PK) studies were undertaken. Patient and graft survival were 52 patients (93%) and 51 grafts (91%), with a follow-up of 23 months (range, 6 to 35 months). One episode (1.8%) of hepatic artery thrombosis was seen. The rate of acute cellular rejection was 14%. No extra treatment was administered in 3 of 8 patients, and the other 5 episodes responded to a single course of steroids. Cytomegalovirus infection occurred in 4 patients (7%). Renal function, glucose control, and lipid metabolism are near normal in 47 patients (84%) without additional medication. Steroid elimination is completed in 51 patients (91%). Bioavailability of SRL and TAC varied between transplant recipients, but trough levels strongly correlated with the area under the curve (r2 = 0.82 and r2 = 0.84, respectively). Simultaneous administration did not affect the PK profile of the drugs at this dose. The ratio of trough level to daily dose correlated between SRL and TAC. The synergistic effect seen in animal models also occurs in clinical liver transplant recipients on SRL-TAC combination immunosuppression. A low-dose combination of SRL and TAC should be compared with conventional immunosuppression in a multicenter, randomized, controlled trial. [source] Leflunomide therapy for BK virus allograft nephropathy in pediatric and young adult kidney transplant recipientsPEDIATRIC TRANSPLANTATION, Issue 1 2010Carlos E. Araya Araya CE, Garin EH, Neiberger RE, Dharnidharka VR. Leflunomide therapy for BK virus allograft nephropathy in pediatric and young adult kidney transplant recipients. Pediatr Transplantation 2010: 14: 145,150. © 2009 Wiley Periodicals, Inc. Abstract:, BKVAN affects about 5% of kidney transplant recipients and may lead to graft failure. Treatment for BKVAN is challenging. Leflunomide, an immunosuppressant with antiviral activity in vitro was used successfully in some adult patients but there are no reports of its use in pediatric patients. We present our experience with three kidney transplant recipients with BKVAN who received leflunomide. Three male patients aged 9, 12, and 20 yr developed BKVAN at 9, 12, and 2 months after a kidney transplant. Immunosuppression was reduced and cidofovir was administered in all patients 2,3 wk apart. Due to inability to travel to receive cidofovir in one, lack of reduction in BK viral load in the second, and rising serum creatinine despite cidofovir in the third patient, we discontinued cidofovir and initiated leflunomide. Teriflunomide target trough levels were 30,60 ,g/mL. The patients received leflunomide for 27, 26, and 24 months, respectively. BK viral load decreased below 1000 DNA copies/mL in one and was undetectable in two patients after beginning leflunomide. All patients tolerated leflunomide without side effects. Leflunomide use in a select group of patients is well tolerated and may provide an alternative for treatment of BKVAN in pediatric patients. [source] Delayed Introduction of Reduced-Dose Tacrolimus, and Renal Function in Liver Transplantation: The ,ReSpECT' StudyAMERICAN JOURNAL OF TRANSPLANTATION, Issue 2 2009J. M. Neuberger We report a multicenter, prospective, randomized, open-label trial investigating the effect of lower levels and delayed introduction of tacrolimus on renal function in liver transplant recipients. Adult patients with good renal function undergoing primary liver transplant were randomized to either: group A (standard-dose tacrolimus [target trough levels >10 ng/mL] and corticosteroids; n = 183); group B (mycophenolate mofetil [MMF] 2g/day, reduced-dose tacrolimus [target trough levels ,8 ng/mL], and corticosteroids; n = 170); group C (daclizumab induction, MMF, reduced-dose tacrolimus delayed until the fifth day posttransplant and corticosteroids, n = 172). The primary endpoint was change from baseline in estimated glomerular filtration rate (eGFR) at 52 weeks. The eGFR decreased by 23.61, 21.22 and 13.63 mL/min in groups A, B and C, respectively (A vs C, p = 0.012; A vs B, p = 0.199). Renal dialysis was required less frequently in group C versus group A (4.2% vs. 9.9%; p = 0.037). Biopsy-proven acute rejection rates were 27.6%, 29.2% and 19.0%, respectively. Patient and graft survival was similar. In conclusion, daclizumab induction, MMF, corticosteroids and delayed reduced-dose tacrolimus was associated with less nephrotoxicity than therapy with standard-dose tacrolimus and corticosteroids without compromising efficacy or tolerability. [source] Conversion to Sirolimus in Renal Transplant Recipients: A Single-Center ExperienceARTIFICIAL ORGANS, Issue 8 2010Berna Yelken Abstract Maintenance immunosuppression with calcineurin inhibitors (CNI) following renal transplantation is associated with nephrotoxicity and accelerated graft loss. Sirolimus (SRL) is a nonnephrotoxic immunosuppressive agent. We retrospectively analyzed our experience with kidney transplant recipients who were converted from CNI to SRL. A total of 58 renal transplant recipients were converted from CNI to SRL. SRL was started at a dose of 0.075 mg/kg and, at the same time, CNI dose was reduced by 50% daily for 3 days. SRL trough levels were targeted between 8 and 12 ng/mL. When target trough levels were achieved, CNI was withdrawn. The main indications for switching were posttransplant malignancies (n = 32) and chronic allograft nephropathy (CAN) (n = 10). The mean time from transplantation to conversion was 84 ± 71 months. Mean serum creatinine level was 1.63 ± 0.52 mg/dL before conversion. Serum creatinine levels at the 1, 3, 6 months, and 1, 2, 3 years after conversion were 1.64 ± 0.58 mg/dL (P = 0.67), 1.52 ± 0.53 mg/dL (P = 0.414), 1.62 ± 0.62 mg/dL (P = 0.734), and 1.48 ± 0.58 mg/dL (P = 0.065), 1.58 ± 0.53 mg/dL (P = 0.854), 1.88 ± 0.77 mg/dL (P = 0.083), respectively. Daily proteinuria levels increased from 0.04 ± 0.11 g/day at baseline to 0.55 ± 1.33 g/day (P = 0.037) after conversion, in the responders group. In the nonresponders group, baseline proteinuria was 0.13 ± 0.25 g/day, and increased to 1.44 ± 2.44 g/day after conversion (P = 0.008). SRL was discontinued in 16 patients (31%) because of the occurrence of severe side effects. The proportion of patients remaining on SRL therapy over time was 43.1% at 1 year, 15.5% at 2 years after conversion, and 10.3% at 3 years after conversion. SRL conversion may be very useful in patients suffering from neoplasia; however, frequent side effects related with this intervention should be considered, and routine conversion from CNI to SRL to reduce nephrotoxicity should be discouraged. [source] A randomized trial of thymoglobulin vs. alemtuzumab (with lower dose maintenance immunosuppression) vs. daclizumab in renal transplantation at 24 months of follow-upCLINICAL TRANSPLANTATION, Issue 2 2008Gaetano Ciancio Abstract: Introduction: A long-term prospective randomized trial evaluating alemtuzumab, a humanized anti-CD52 monoclonal antibody, in a predominantly non-Caucasian population has yet to be reported. Methods: Ninety deceased donor (DD) first renal transplant recipients were randomized into three different antibody induction groups: group A, thymoglobulin (Thymo); group B, alemtuzumab; group C, daclizumab (Dac). In groups A and C, the target trough levels of tacrolimus were 8,10 ng/mL, mycophenolate mofetil (MMF) 1 g administered twice daily, and maintenance methylprednisolone. In group B, target tacrolimus trough levels were 4,7 ng/mL, 500 mg MMF administered twice-daily, without methylprednisolone. African-Americans and Hispanics comprised more than 50% in each group. Results: A minimum follow-up of 27 months showed no overall group differences in patient or graft survival (p = 0.89 and 0.66), but a trend towards worse death-censored graft survival in group B (p = 0.05). Acute rejection rates were not significantly different: six (20%), seven (23%), and seven (23%) in groups A, B, and C, respectively. The incidence of chronic allograft nephropathy was higher in group B than in A and C (p = 0.008). The mean calculated creatinine clearance at 24 months was 81.1 ± 5.5, 64.4 ± 4.5, and 80.7 ± 5.7 in groups A, B, and C, respectively (p = 0.01 for B vs. average of A and C). Conclusion: In this randomized 27-month minimum follow-up trial of predominantly non-Caucasian DD renal transplant recipients with alemtuzumab induction, lower maintenance tacrolimus, MMF, and steroid avoidance appear less effective than either Thymo or Dac with higher maintenance immunosuppression. 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