Wen-Yuan Johnson Kuan1, Nathalie Châteauvert2, Vincent Leclerc3, Benoît Drolet4. 1. , PharmD, MSc, is a Pharmacist with the Department of Pharmacy, Centre intégré de santé et de services sociaux des Laurentides, Hôpital de Saint-Eustache, Saint-Eustache, Quebec, and Chargé d'enseignement clinique (Clinical Preceptor) with the Faculty of Pharmacy, Université Laval, Québec, Quebec. 2. , BPharm, MSc, is a Pharmacist with the Department of Pharmacy, Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval (IUCPQ-UL), and Clinical Professor with the Faculty of Pharmacy, Université Laval, Québec, Quebec. 3. , BPharm, MSc, is a Pharmacist with the Department of Pharmacy, Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval (IUCPQ-UL), and Chargé d'enseignement clinique (Clinical Preceptor) with the Faculty of Pharmacy, Université Laval, Québec, Quebec. 4. , BPharm, PhD, is an Investigator with the Research Centre, Institut universitaire de cardiologie et de pneumologie de Québec - Université Laval (IUCPQ-UL), and Professor with the Faculty of Pharmacy, Université Laval, Québec, Quebec.
Abstract
BACKGROUND: Tacrolimus may be administered during hospitalization as an IV formulation or oral suspension. However, literature suggesting appropriate ratios for conversion from these formulations to capsules is limited. OBJECTIVE: To evaluate conversion ratios after a switch in formulation of tacrolimus for solid-organ transplant recipients. METHODS: This single-centre observational longitudinal study involved hospitalized patients who underwent a switch in formulation of tacrolimus according to 1 of 3 possible scenarios: IV to oral suspension, IV to capsule, or oral suspension to capsule. Data were collected from the earliest accessible electronic file (January 2009) to January 1, 2019. Conversion ratios were calculated for each of the 3 groups using data for blood concentrations and doses before and after the switch. The calculated ratios were then compared with recommended conversion ratios: 1:5 (i.e., 1 mg of IV tacrolimus is converted to 5 mg of oral tacrolimus, expressed as "5") for either of the switches involving an IV formulation and 1:1 (i.e., same amount, expressed as "1") for the switch from oral formulation to capsules. RESULTS: For the group who underwent switching from the IV formulation to oral suspension, the mean calculated conversion ratio was 3.04, which was significantly different from the recommended ratio of 5. For the group who underwent switching from the IV formulation to capsules, the calculated conversion ratio was 5.18, which was not significantly different from the recommended ratio of 5. For the group who underwent switching from oral suspension to capsules, the calculated conversion ratio was 1.17, which was not significantly different from the recommended ratio of 1. CONCLUSION: In this small retrospective study of tacrolimus therapy, the calculated conversion ratio was significantly different from the recommended ratio for patients who were switched from IV administration to oral suspension, but not for those switched from IV administration or oral suspension to capsules. Therapeutic drug monitoring therefore appears indispensable, regardless of conversion ratios. 2021 Canadian Society of Hospital Pharmacists. All content in the Canadian Journal of Hospital Pharmacy is copyrighted by the Canadian Society of Hospital Pharmacy. In submitting their manuscripts, the authors transfer, assign, and otherwise convey all copyright ownership to CSHP.
BACKGROUND: Tacrolimus may be administered during hospitalization as an IV formulation or oral suspension. However, literature suggesting appropriate ratios for conversion from these formulations to capsules is limited. OBJECTIVE: To evaluate conversion ratios after a switch in formulation of tacrolimus for solid-organ transplant recipients. METHODS: This single-centre observational longitudinal study involved hospitalized patients who underwent a switch in formulation of tacrolimus according to 1 of 3 possible scenarios: IV to oral suspension, IV to capsule, or oral suspension to capsule. Data were collected from the earliest accessible electronic file (January 2009) to January 1, 2019. Conversion ratios were calculated for each of the 3 groups using data for blood concentrations and doses before and after the switch. The calculated ratios were then compared with recommended conversion ratios: 1:5 (i.e., 1 mg of IV tacrolimus is converted to 5 mg of oral tacrolimus, expressed as "5") for either of the switches involving an IV formulation and 1:1 (i.e., same amount, expressed as "1") for the switch from oral formulation to capsules. RESULTS: For the group who underwent switching from the IV formulation to oral suspension, the mean calculated conversion ratio was 3.04, which was significantly different from the recommended ratio of 5. For the group who underwent switching from the IV formulation to capsules, the calculated conversion ratio was 5.18, which was not significantly different from the recommended ratio of 5. For the group who underwent switching from oral suspension to capsules, the calculated conversion ratio was 1.17, which was not significantly different from the recommended ratio of 1. CONCLUSION: In this small retrospective study of tacrolimus therapy, the calculated conversion ratio was significantly different from the recommended ratio for patients who were switched from IV administration to oral suspension, but not for those switched from IV administration or oral suspension to capsules. Therapeutic drug monitoring therefore appears indispensable, regardless of conversion ratios. 2021 Canadian Society of Hospital Pharmacists. All content in the Canadian Journal of Hospital Pharmacy is copyrighted by the Canadian Society of Hospital Pharmacy. In submitting their manuscripts, the authors transfer, assign, and otherwise convey all copyright ownership to CSHP.
Entities:
Keywords:
conversion ratio; formulation; solid-organ transplant; tacrolimus; therapeutic drug monitoring
Authors: L M Mancinelli; L Frassetto; L C Floren; D Dressler; S Carrier; I Bekersky; L Z Benet; U Christians Journal: Clin Pharmacol Ther Date: 2001-01 Impact factor: 6.875
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