title: An observational study evaluating tacrolimus dose, exposure, and medication adherence after conversion from twice- to once-daily tacrolimus in liver and kidney transplant recipients.
abstract: BACKGROUND
  Immunosuppression regimens in transplantation medicine are complex. Drugs with extended release action have simplified medication dosing without affecting efficacy.
  
  
  METHODS
  This prospective, observational, multicenter study, conducted in a routine medical practice setting, evaluated changes in tacrolimus daily dose and trough levels and patient-reported medication adherence at day 90 after 1:1 (mg: mg) conversion to once-daily tacrolimus in adult liver and kidney transplant recipients.
  
  
  RESULTS
  Data from 224 recipients of a liver (n=19) or kidney (n=205) transplant, average age 51±14.5 years, were evaluated. The mean change in tacrolimus daily dose was +0.04 mg/day. Dose remained stable after conversion in 62.5%, was lower in 15.6%, and higher in 22% of patients. Trough level after conversion was lower in 62.6% and higher in 36.5%; generally, levels were 12.8% lower than pre-conversion levels. No acute rejection, graft loss, or serious safety events were observed. Two deaths occurred due to myocardial infarction. Conversion helped 19% to less frequently forget medications and 55% reported no difference in remembering to take the once-daily dose after conversion. The change in dosing frequency was identified as "better" for 55%.
  
  
  CONCLUSIONS
  Tacrolimus daily dose remained stable while trough levels were significantly lower after conversion to once-daily dosing. Safety and efficacy were maintained; reduced dosing frequency had no apparent influence on patient-reported medication adherence.
authors.affiliation: Departent of Transplantation, Uppsala University Hospital, Uppsala, Sweden.
authors.forename: Lars
authors.initials: L
authors.lastname: Bäckman
authors.affiliation: Department of Transplantation, Astellas Pharma, Kastrup, Denmark.
authors.forename: Carl-Axel
authors.initials: CA
authors.lastname: Persson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D006084:Graft Rejection / Q000188:drug therapy*; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage*; D016030:Kidney Transplantation; D016031:Liver Transplantation; D008297:Male; D055118:Medication Adherence; D008875:Middle Aged; D016559:Tacrolimus / Q000008:administration & dosage*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D007166:Immunosuppressive Agents; D016559:Tacrolimus