A randomized, open-label pharmacokinetic trial of tacrolimus extended-release dosing in obese de novo kidney transplant recipients.

PURPOSE: Tacrolimus extended-release (TAC-ER; Astagraf XL® ) is utilized in many immunosuppressive regimens post-renal transplantation. Current dosing recommendation for the TAC-ER in renal transplant is 0.15-0.2 mg/kg/day administered once daily. The purpose of this study was to determine the best method of dosing TAC-ER in obese renal transplant recipients. METHODS: De novo obese kidney transplant recipients were randomized to receive TAC-ER 0.15 mg/kg/day based on either adjusted body weight (aBW) or ideal body weight (IBW). Post-transplant patients underwent three pharmacokinetic assessments over 14 days. The primary endpoint was the difference in TAC-ER exposure (AUC0-24) in obese patients dosed using aBW compared with IBW. RESULTS: A total of 20 obese renal transplant recipients were randomized to participate in the study (10 aBW and 10 IBW). Results of the primary outcome (AUC0-24) on Study Day 1, 7, and 14 were not statistically different between the two groups. There was no difference in the number of days to therapeutic trough concentration between the two dosing weights (aBW = 5.1, IBW = 4.9, days; P = 0.90). CONCLUSION: In a population of obese renal transplant recipients, comparable trough concentrations and overall exposure in both groups indicate that IBW may be preferred, as less initial drug was needed to attain adequate exposure.

Removal of Anti-Thymocyte Globulin by Plasma Exchange in ABO-Incompatible and Positive Crossmatch Kidney Transplant Recipients.

BACKGROUND: Recipients of ABO-incompatible (ABOI) and positive crossmatch (PXM) kidney transplants are at high risk for antibody-mediated acute rejection. Despite aggressive immunosuppression in high-risk patients, the incidence of acute rejection remains considerably higher than in other groups. No published studies have examined plasma concentrations of anti-thymocyte globulin (ATG) in patients undergoing plasma exchange. The objectives of this study were to compare plasma ATG concentrations before and after plasma exchange in ABOI and PXM kidney transplant patients to determine the amount removed. MATERIALS AND METHODS: This prospective pharmacokinetic evaluation enrolled 10 patients undergoing ABOI or PXM kidney transplant at an academic medical center. Blood and waste plasma samples from 5 patients were assayed for total and active ATG concentrations. Patient records were monitored for renal function and rejection rates in the first 6 months post-transplant. RESULTS: Total ATG concentrations decreased a mean of 59.78 ± 13.91% after each plasma exchange session, and active ATG levels decreased a mean of 56.8 ± 17.08%. Mean daily concentrations reflect a lack of expected ATG accumulation. Only 1 of 4 patients had detectable ATG concentrations after 30 days. After 6 months, the incidence of acute rejection in this sample was 44% and graft survival was 89%. CONCLUSIONS: This is the first study to show that plasma exchange removes a substantial amount of ATG in high-risk kidney transplant patients. Based on these results, we believe these high-risk patients have been traditionally underdosed.

Balance of academic responsibilities of clinical track pharmacy faculty in the United States: a survey of select American College of Clinical Pharmacy Practice and Research Network Members.

STUDY OBJECTIVES: To characterize the balance of clinical and academic responsibilities of clinical track pharmacy faculty in the United States and evaluate organizational structures that promote satisfactory balance between these responsibilities. DESIGN: Prospective cross-sectional survey. SETTING: A 22-item online survey was developed and distributed via Qualtrics software. PARTICIPANTS: Clinical faculty members of the American College of Clinical Pharmacy Adult Medicine, Ambulatory Care, Cardiology, Critical Care, Gastrointestinal/Liver/Nutrition, Immunology/Transplantation, Infectious Disease, and Pediatrics Practice and Research Networks (PRNs) were invited to participate via the PRN electronic mailing list. MEASUREMENTS AND MAIN RESULTS: The survey comprised questions related to demographics, organizational structure, and balance of clinical and academic responsibilities. A total of 344 participants responded to some or all of the survey questions. The demographics were relatively equally balanced between faculty at state and private academic institutions, academic rank, and practice setting. Expected and actual effort allocations were similar for each of the clinical and academic responsibilities, with direct patient care and clinical teaching representing more than 50% effort allocation cumulatively. Clinical faculty at state institutions devoted a larger proportion of time to clinical service, whereas clinical faculty at private institutions devoted a greater proportion of time to didactic teaching. When asked about time constraints, 157 (69.8%) of the 225 survey participants responding to this question did not believe they had sufficient time to fulfill their nonclinical academic needs. Clinical faculty who were provided "protected time" away from clinical service had a significantly more favorable opinion of this question. CONCLUSION: Most of the clinical track pharmacy faculty indicated that they have insufficient time to fulfill their nonclinical academic responsibilities. Provision of protected time may alleviate some of these time constraints.

Living donor kidney transplantation across positive crossmatch: the University of Illinois at Chicago experience.

BACKGROUND: To increase living donation for kidney transplantation, we investigated desensitization of recipients with positive crossmatch against a potential living donor. METHODS: Between June 2001 and March 2007, 57 consecutive sensitized candidates for kidney transplantation, with crossmatch positive potential living donors, were treated with various desensitization protocols. All patients received plasmapheresis every other day with intravenous immune globulin 100 mg/kg starting 1 week before the scheduled transplant. Postoperatively, the recipients continued to receive every other day plasmapheresis with intravenous immune globulin for the initial week. Immunosuppression therapy consisted of induction with thymoglobulin and a combination of tacrolimus, mycophenolate, and corticosteroids. RESULTS: Six patients failed to convert with pretransplant immunomodulation and were not transplanted; 51 underwent live donor kidney transplant. Mean follow-up was 23 months and 36 patients have more than 1-year follow-up. One-year patient and graft survivals were 95% and 93%, respectively. There were 25 episodes of biopsy-proven or clinically presumed rejection in 22 patients in the first year. Of the 17 biopsy-proven episodes, 12 were antibody-mediated rejection and five were acute cellular rejection. Of the patients with antibody-mediated rejection (biopsy proven or empiric), two patients (12%) lost their graft by 1 year. The median modification of diet in renal disease at 6 and 12 months was 55 mL/min (range 9-104 mL/min) and 48 mL/min (range 8-99), respectively. CONCLUSIONS: Despite increased rejection rates, graft and patient survivals indicate that desensitization of positive crossmatch patients is a reasonable alternative for a sensitized patient who could potentially wait 10 or more years for a suitable cadaveric kidney.