![Sample our Bioscience journals, sign in here to start your access, Latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5925/TOC-Subject-Sample-2021-Bioscience.jpg"})
![Publish Open Access Finland]({"type":"image" , "src" : "/sda/110396/JournalAd-OA-Agreements.gif"})
![Electronic Banner Advert for Current Medical Research and Opinion]({"type":"image" , "src" : "/sda/111144/JournalAd-Announce-ICMO-LM.jpg"})
Abstract
Objective
Although existing studies have compared clinical efficacy and pharmacokinetics of generic with brand tacrolimus, little is known about generic tacrolimus utilization patterns or factors predicting generic substitution. This study examines associations between patient-level factors and generic tacrolimus initiation or substitution among new users of oral generic or brand-name tacrolimus.
Methods
This new user retrospective cohort study identified 374 beneficiaries who initiated generic or brand tacrolimus treatment, using 100% Medicaid administrative claims data from 11 states in 2011–2012. Outcomes were generic tacrolimus initiation and substitution within 12 months of treatment initiation. Multivariable logistic regression and Cox proportional hazards models were used to identify factors associated with generic tacrolimus initiation and substitution.
Results
Two-thirds of oral tacrolimus new users initiated generic tacrolimus. Patients who were older age and black were significantly more likely to initiate generic tacrolimus (adjusted odds ratio [AOR] = 1.02, 95% confidence interval [CI] = 1.001–1.03; AOR = 2.54, 95% CI = 1.40–4.62; respectively). Patients with more concomitant prescriptions, more comorbidities, or higher initial daily dosage had significantly lower likelihoods of initiating generic tacrolimus (AOR = 0.93, 95% CI = 0.87–0.99; AOR = 0.87, 95% CI = 0.77–0.99; AOR = 0.96, 95% CI = 0.93–0.993). Among brand tacrolimus new users, 23.6% substituted with generics within 12 months, and an addition of prior hospitalization or unit of initial daily dosage increment was associated with 35% (subdistribution hazard ratio [SHR] = 1.35, 95% CI = 1.02–1.76) or 2% (SHR = 1.02, 95% CI = 1.00–1.04) increase in likelihood of generic substitution, respectively.
Conclusions
Understanding associations between patient-level factors with generic tacrolimus initiation and substitution could help practitioners and policymakers monitor treatment effect and facilitate generic tacrolimus utilization.
Acknowledgements
None reported.
Transparency
Declaration of funding
Funding for this manuscript was made possible, in part, by the U.S. Food and Drug Administration (FDA) grant # U01FD005875. Views expressed in written materials or publications and by speakers and moderators do not necessarily reflect the official policies of the Department of Health and Human Services; nor does any mention of trade names, commercial practices, or organization imply endorsement by the United States Government.
Declaration of financial/other relationships
In the past 3 years, RAH has provided expert testimony for Daiichi Sankyo and Takeda. No other authors declare a potential conflict of interest. Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.
Author contributions
LC and JQ had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: JQ, LC, RAH, IH; acquisition, analysis, or interpretation of data: JQ, LC, CL, NH, AUM; drafting of the manuscript: LC, CL, JQ; critical revision of the manuscript for important intellectual content: all authors; statistical analysis: CL, NH, AUM; obtained funding: JQ, RAH, IH, ZK; administrative, technical, or material support: JQ, LC; study supervision: JQ.