Characterizing the Use of Prolonged-Release Once-Daily Tacrolimus (LCPT) across Canada.

Background: Tacrolimus is the most common calcineurin inhibitor given to kidney and liver transplant recipients. Prolonged-release once-daily tacrolimus (LCPT) is the newest formulation of this drug, but prescribing practices for tacrolimus across Canada are unknown.

Objectives: To investigate the use of tacrolimus across Canada, by determining coverage for the drug, exploring prescribing practices and factors related to decision-making, and identifying management methods for patients with rapid metabolism of tacrolimus.

Methods: A mixed-methods, descriptive study using survey-based data collection and qualitative interviews was undertaken. The medical director and a pharmacist from each adult kidney and liver transplant centre in Canada were invited to complete an electronic questionnaire consisting of 8 open-ended questions concerning their respective transplant programs' coverage for and use of tacrolimus. Interested participants completed a one-on-one virtual follow-up interview to explore experiences.

Results: A total of 28 health care providers participated in the survey, of whom 18 completed an interview, achieving representation from 15 (79%) of 19 kidney transplant programs and 3 (38%) of 8 liver transplant programs. Prescribing habits varied, with immediate-release tacrolimus (IR-Tac) being the most commonly preferred formulation (due to provider experience), followed by extended-release tacrolimus (ER-Tac) and LCPT. Most survey respondents (26/28) indicated that their centres used LCPT for maintenance but not de novo immunosuppression. The most common reason for conversion to LCPT was to reduce tremors or to address suspected rapid metabolism; barriers to uptake of LCPT included perceived disadvantages related to cost and coverage.

Conclusions: Prescribing practices for tacrolimus varied across Canada. IR-Tac was the most commonly used formulation, followed by ER-Tac. LCPT was used primarily in the maintenance phase for people with neurotoxicity or rapid metabolism, but there was a lack of consistency in how rapid metabolism was defined.