| 1. |
- Kanai, M, et al.
(författare)
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- 2023
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swepub:Mat__t
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| 2. |
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| 3. |
- Hamberg, Anna-Karin, et al.
(författare)
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Characterising variability in warfarin dose requirements in children using modelling and simulation
- 2013
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Ingår i: British Journal of Clinical Pharmacology. - : Wiley. - 0306-5251 .- 1365-2125. ; 78:1, s. 158-169
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: Although genetic, clinical and demographic factors have been shown to explain approximately half of the inter-individual variability in warfarin dose requirement in adults, less is known about causes of dose variability in children. This study aimed to identify and quantify major genetic, clinical and demographic sources of warfarin dose variability in children using modelling and simulation.METHODS: Clinical, demographic and genetic data from 163 children with a median age of 6.3 years (range 0.06-18.9 years), covering over 183 years of warfarin therapy and 6445 INR observations were used to update and optimise a published adult pharmacometric warfarin model for use in children.RESULTS: Genotype effects in children were found to be comparable to what has been reported for adults, with CYP2C9 explaining up to a 4-fold difference in dose (CYP2C9 *1/*1 vs. *3/*3) and VKORC1 explaining up to a 2-fold difference in dose (VKORC1 G/G vs. A/A), respectively. The relationship between bodyweight and warfarin dose was non-linear, with a 3-fold difference in dose for a 4-fold difference in bodyweight. In addition, age, baseline and target INR, and time since initiation of therapy, but not CYP4F2 genotype, had a significant impact on typical warfarin dose requirements in children.CONCLUSIONS: The updated model provides quantitative estimates of major clinical, demographic and genetic factors impacting warfarin dose variability in children. With this new knowledge more individualised dosing regimens can be developed and prospectively evaluated in the pursuit of improving both efficacy and safety of warfarin therapy in children.
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| 4. |
- Hamberg, Anna-Karin, et al.
(författare)
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Predicting the relative importance of genetic, clinical and demographic factors on warfarin dose in children using pharmacometric modelling
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- It is difficult to predict anticoagulation response to warfarin in children mainly because of a wide inter-individual variability in warfarin dose requirement. The present study objective was to identify important predictors of dose in children and to optimize a previous NONMEM warfarin model for a priori and a posteriori dose and INR predictions in children. Data from 163 warfarin treated children with underlying heart disease (median age 6.3 years) were used. CYP2C9 and VKORC1 genotype caused up to 4-fold and 2-fold differences in warfarin dose requirement, respectively. Other important predictors of warfarin dose were bodyweight, age, baseline and target INR, and time since initiation of therapy with lower doses during the initiation. CYP4F2 genotype had only a marginal effect on dose. The present study findings will aid the development of a personalised approach to warfarin therapy in children, in the pursuit of improving both efficacy and safety of anticoagulation therapy.
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