Abstract | OBJECTIVE: To evaluate the influence of genetic polymorphism in UGT1A1, UGT1A7 and UGT1A9 on the population pharmacokinetics of irinotecan and its metabolites, SN-38 and SN-38G. METHODS: Plasma concentrations of irinotecan, SN-38 and SN- 38G from 72 patients were pooled to develop a population pharmacokinetic model using NONMEM VII. M3 method was used to account for plasma concentrations below the limit quantification. The effect of age, sex, body surface area, total bilirubin, co-medication, tumor type, and UGT1A1, UGT1A7 and UGT1A9 genotypes on the model parameters was evaluated. The model was internally validated using normalized visual predictive check ( NVPC) and normalized predictive distribution errors (NPDE). RESULTS: The typical values (between-subject variability; %) of the irinotecan, SN-38 and SN-38G clearances were 42,9 L/h (56,4%), 1340 L/h (76,8%) and 188 L/h (70,1%), respectively. The presence of UGT1A1*28, UGT1A7*3, UGT1A9*22 genotypes decreases SN-38 clearance between 20 and 36%. Internal validation confirms the population pharmacokinetic model describe the time course of irinotecan, SN-38 and SN-38G plasma concentration and their associated variability in cancer patients. CONCLUSION: The inclusion of pharmacokinetic-pharmacogenomic information can add value to the individualized dose adjustment of irinotecan, because it will let quantitatively handle dose reductions in patients with iatrogenic toxicity due to UGT1A1 genetic polymorphisms.
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Authors | B Valenzuela Jiménez, M González Sales, V Escudero Ortiz, E Martínez Navarro, C Pérez Ruixo, J Rebollo Liceaga, R González Manzano, J J Pérez Ruixo |
Journal | Farmacia hospitalaria : organo oficial de expresion cientifica de la Sociedad Espanola de Farmacia Hospitalaria
(Farm Hosp)
2013 Mar-Apr
Vol. 37
Issue 2
Pg. 111-27
ISSN: 2171-8695 [Electronic] Spain |
Vernacular Title | Influencia de los polimorfismos genéticos en UGT1A1, UGT1A7 y UGT1A9 sobre la farmacocinética de irinotecán, SN-38 y SN-38G. |
PMID | 23789755
(Publication Type: Journal Article)
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Copyright | Copyright © 2013 SEFH. Published by AULA MEDICA. All rights reserved. |
Chemical References |
- 7-ethyl-10-hydroxycamptothecin beta-glucuronide
- Antineoplastic Agents, Phytogenic
- Glucuronates
- UGT1A9 protein, human
- Irinotecan
- UGT1A1 enzyme
- Glucuronosyltransferase
- UDP-Glucuronosyltransferase 1A9
- UGT1A7 protein, human
- Camptothecin
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Topics |
- Adult
- Aged
- Aged, 80 and over
- Antineoplastic Agents, Phytogenic
(blood, pharmacokinetics, therapeutic use)
- Camptothecin
(analogs & derivatives, blood, pharmacokinetics, therapeutic use)
- Female
- Glucuronates
(blood, pharmacokinetics, therapeutic use)
- Glucuronosyltransferase
(genetics)
- Humans
- Irinotecan
- Male
- Middle Aged
- Neoplasms
(drug therapy, genetics)
- Polymorphism, Genetic
- UDP-Glucuronosyltransferase 1A9
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