Iván Saavedra | Universidad de Chile (original) (raw)
Papers by Iván Saavedra
Revista médica de Chile, 1996
We measured plasma concentrations of amiodarone and desethylamiodarone by HPLC in 44 outpatients ... more We measured plasma concentrations of amiodarone and desethylamiodarone by HPLC in 44 outpatients aged 24 to 67 years old (21 male), receiving the drug during at least three months. The drug was indicated for supraventricular arrhythmias in 37 patients and ventricular arrhythmias in seven. Plasma concentrations of amiodarone, desethylamiodarone and their ratio were 1.71 +/- 0.82, 0.85 +/- 0.42 micrograms/ml and 2.02 respectively, for a mean daily dose of 223 +/- 88 mg. In 41 patients, arrhytmias were successfully treated. These patients received a mean daily dose of 220 +/- 86 mg and concentrations of amiodarone, desethylamiodarone and their ratio were 1.75 +/- 0.86, 0.88 +/- 0.45 micrograms/ml and 1.99 respectively. In three patients with treatment failure, receiving a daily dose of 257 +/- 115 mg, these figures were 1.2 +/- 0.3, 0.5 +/- 0.1 micrograms/ml and 2.4 respectively. We conclude that our patients had lower plasma concentrations of desethylamiodarone and higher amiodarone/d...
Rev Chil Cardiol, Jun 1, 2006
![Research paper thumbnail of [Cancer pharmacogenetics: study of genetically determined variations on cancer susceptibility due to xenobiotic exposure]](https://attachments.academia-assets.com/41165841/thumbnails/1.jpg)
](Revista Medica De Chile, Apr 1, 2006
Revista Medica De Chile, Jun 1, 2003
Bioavailability of a particular drug can vary according to the formulation used. Therefore, studi... more Bioavailability of a particular drug can vary according to the formulation used. Therefore, studies of comparative bioavailability of different formulations of a same drug are worthwhile. To compare the bioavailability of two risperidone formulations available in the Chilean market. The bioavailability of a local risperidone formulation (Spiron) was compared with the original formulation of the drug (Risperdal) in 12 healthy volunteers, aged 19 +/- 1 years. A single dose of 3 mg was given orally, using a randomized double blind protocol in two periods. Fifteen blood samples were obtained at regular intervals, until 24 h after drug administration. Risperidone plasma levels were measured by high pressure liquid chromatography. pharmacokinetic parameters were calculated using a computer program that is independent of compartmental analysis. The area under the curve of plasma concentration versus time, from 0 to infinite (ABC0-infinity) and from 0 to 24 h (ABC0-24), early exposure (ABC from 0 to maximal time) and maximal plasma concentrations were significantly lower for Spiron. Half life time and time to achieve the maximal concentration were similar for the two formulations. According to bioequivalence tests suggested by the Food and Drug Administration (FDA) of the United States (90% confidence interval for the difference of long transformed mean pharmacokinetic parameters), the formulations Risperdal and Spiron, cannot be considered interchangeable.
Biomedica Revista Del Instituto Nacional De Salud, Jun 14, 2012
Introduction.Levonorgestrel a synthetic progestagen used for endometriosis, dysmenorrhea and emer... more Introduction.Levonorgestrel a synthetic progestagen used for endometriosis, dysmenorrhea and emergency contraception, is quickly and completely absorbed in the digestive tract. levonorgestrel is predominantly metabolised through hepatic routes that utilise the CYP3A system (CYP3A4 and CYP3A5).
![Research paper thumbnail of [Influence of CYP3A4/5 polymorphisms in the pharmacokinetics of levonorgestrel: a pilot study]](https://attachments.academia-assets.com/41165981/thumbnails/1.jpg)
](Biomédica : revista del Instituto Nacional de Salud
Levonorgestrel a synthetic progestagen used for endometriosis, dysmenorrhea and emergency contrac... more Levonorgestrel a synthetic progestagen used for endometriosis, dysmenorrhea and emergency contraception, is quickly and completely absorbed in the digestive tract. levonorgestrel is predominantly metabolised through hepatic routes that utilise the CYP3A system (CYP3A4 and CYP3A5). This study aimed to evaluate the association between variant alleles of CYP3A4*1B and CYP3A5*3 polymorphisms and the pharmacokinetics of levonorgestrel. A group of 17 adult female healthy volunteers who signed an informed consent were genotyped for CYP3A4 and CYP3A5 through PCR-RFLP. Volunteers were submitted to pharmacokinetic analysis where, after a 12-hour overnight fast, they received a single oral dose of 0.75 mg of levonorgestrel. Serial blood samples were obtained (0 to 24 hours), and levonorgestrel concentrations were determined by UPLC-MS/MS to determine pharmacokinetic parameters. The procedures employed herein were performed according to the Declaration of Helsinki and Good Clinical Practices st...
Oncology letters, 2010
Polycyclic aromatic hydrocarbons (PAHs) contained in tobacco smoke acquire carcinogenicity follow... more Polycyclic aromatic hydrocarbons (PAHs) contained in tobacco smoke acquire carcinogenicity following their activation by xenobiotic-metabolizing enzymes to highly reactive metabolites. The cytochrome P4501A1 (CYP1A1) enzyme is central to the metabolic activation of these PAHs, and GSTM1 is the main enzyme responsible for its detoxification. CYP1A1 and GSTM1 polymorphisms were evaluated in 124 Chilean healthy controls and 48 oral cancer patients through PCR-based restriction fragment length polymorphism. In the healthy controls, frequencies of the CYP1A1 variant alleles for m1 (CYP1A1(*)2A) and the GSTM1null genotype were found to be 0.25 and 0.19, respectively. In the oral cancer patients, these frequencies were 0.33 and 0.50, respectively. Thus, the GSTM1 and m1 rare alleles were significantly more frequent in the oral cancer patients compared to the controls. The estimated relative risk for oral cancer associated with the single genotype CYP1A1 or GSTM1 was 2.08 for wt/m1, 1.04 fo...
Comparative Biochemistry and Physiology, 1969
... 6, 9). However, after 15 days, the heavier component is essentially lost when 280 MAR LUISA D... more ... 6, 9). However, after 15 days, the heavier component is essentially lost when 280 MAR LUISA DINAMARCA, IVAN SAAVEDRA AND ELENA VALD GSH is not present. ... DISCUSSION Lipke & Kearns (1959a, b) achieved a purification of DDT-dehydrochlorinase of about 570-fold. ...
Therapeutic drug monitoring, 2004
The objective of this study was to evaluate a possible pharmacokinetic interaction between 17beta... more The objective of this study was to evaluate a possible pharmacokinetic interaction between 17beta-estradiol (E2) and medroxyprogesterone (MP) when administered together in a combined tablet because both hormones have common metabolic routes of biotransformation. The study assessed the mean pharmacokinetics parameters of E2 found after 1-dose administration of 2 different tablets containing E2, 1 containing 2 mg of micronized 17beta-estradiol valerate (E2V) and the other, administered after 2 weeks, 2 mg of E2V in combination with 5 mg of medroxyprogesterone acetate (MPA). The subjects were 15 healthy postmenopausal women with normal laboratory and clinic tests. The study was randomized, double blind, crossover, with 2 periods and 2 sequences. The blood samples were obtained at 0, 1, 2, 3, 4, 6, 8, 10, 12, and 24 hours after each administration. The E2 serum concentrations were determined by electrochemoluminiscence assay. From these data, the following pharmacokinetic parameters wer...
Biomédica, 2012
Introduction.Levonorgestrel a synthetic progestagen used for endometriosis, dysmenorrhea and emer... more Introduction.Levonorgestrel a synthetic progestagen used for endometriosis, dysmenorrhea and emergency contraception, is quickly and completely absorbed in the digestive tract. levonorgestrel is predominantly metabolised through hepatic routes that utilise the CYP3A system (CYP3A4 and CYP3A5).
Revista chilena de cardiología, 2011
Determinación del polimorfismo de CYP2C9*2 y su relación con la farmacocinética de acenocumarol e... more Determinación del polimorfismo de CYP2C9*2 y su relación con la farmacocinética de acenocumarol en voluntarios sanos.
Revista médica de Chile, 2006
Revista chilena de infectología, 2003
... de utilizar indistintamente una formulación u otra, disponiendo de elementos de juicio sufici... more ... de utilizar indistintamente una formulación u otra, disponiendo de elementos de juicio suficientes para ... La claritromicina es un antimicrobiano macrólido de segunda generación, derivado semisintético de la ... C máx ) entre una y dos horas después de la administración oral. ...
Therapeutic Drug Monitoring, 1985
An interaction between phenytoin (PHT) and clonazepam (CZP) occurred in an epileptic patient, who... more An interaction between phenytoin (PHT) and clonazepam (CZP) occurred in an epileptic patient, who had been treated with PHT with partial seizure control. The addition of CZP brought about a significant decrease of PHT plasma levels (from 24.8 to 16 micrograms/ml) in spite of increases in the PHT dose. Gradual reduction of CZP, without modifying the PHT dosage, caused significant increases in PHT plasma levels to 42.4 micrograms/ml with signs of intoxication. A review of the literature shows contradictions: some authors state that there is no interaction between the drugs; other authors state either an increase or decrease in PHT plasma levels. These paradoxical results could be explained by the bidirectional effect of these drugs in hepatic enzyme metabolism. The importance of monitoring plasma levels of antiepileptic drugs is emphasized when several medications are required in the treatment of epilepsy.
Journal of Hydraulic Research, 1999
Résumé/Abstract On présente dans cet article un modèle bidimensionnal aux éléments finis pour la ... more Résumé/Abstract On présente dans cet article un modèle bidimensionnal aux éléments finis pour la simulation du transport de sédiments en suspension en zone côtière. Le modèle consiste en un modèle hydrodynamique, plus un modèle de convection-diffusion ...
Epilepsia, 1980
In a prospective study of 117 adult ambulatory patients, 110 of whom were epileptics treated only... more In a prospective study of 117 adult ambulatory patients, 110 of whom were epileptics treated only with oral diphenylhydantoin (DPH), plasma levels of this drug were determined by gas-liquid chromatography. The average follow-up time was 6 months (range, 3 to 13 months); satisfactory control of seizures was obtained with plasma levels in the 10.2 to 25.8 micrograms/ml range, representing 68% of the patients whose seizures had been controlled. The dosage received by this group was from 4.2 to 6 mg/kg, with an average of 5.1. In general, these results agree with those found in European or North American patients, even though some differences or little clarity in the methodology of other trials make comparison difficult. This similarity of results makes one think that genetic or environmental differences do not alter the response to DPH in our patients, but further studies are necessary in that area. This paper can serve as a basis for the extrapolation of data about DPH coming from other latitudes that have been considered supposedly valid for Latin American epileptic patients.
Frontiers in Genetics, 2012
Cancer is a leading cause of death worldwide. The cancer incidence rate in Chile is 133.7/100,000... more Cancer is a leading cause of death worldwide. The cancer incidence rate in Chile is 133.7/100,000 inhabitants and it is the second cause of death, after cardiovascular diseases. Most of the antineoplastic drugs are metabolized to be detoxified, and some of them to be activated. Genetic polymorphisms of drug-metabolizing enzymes can induce deep changes in enzyme activity, leading to individual variability in drug efficacy and/or toxicity. The present research describes the presence of genetic polymorphisms in the Chilean population, which might be useful in public health programs for personalized treatment of cancer, and compares these frequencies with those reported for Asian and Caucasian populations, as a contribution to the evaluation of ethnic differences in the response to chemotherapy. We analyzed 23 polymorphisms in a group of 253 unrelated Chilean volunteers from the general population. The results showed that CYP2A6 * 2, CYP2A6 * 3, CYP2D6 * 3, CYP2C19 * 3, and CYP3A4 * 17 variant alleles are virtually absent in Chileans. CYP1A1 * 2A allele frequency (0.37) is similar to that of Caucasians and higher than that reported for Japanese people. Allele frequencies for CYP3A5 * 3(0.76) and CYP2C9 * 3(0.04) are similar to those observed in Japanese people. CYP1A1 * 2C(0.32), CYP1A2 * 1F (0.77), CYP3A4 * 1B(0.06), CYP2D6 * 2(0.41), and MTHFR T(0.52) allele frequencies are higher than the observed either in Caucasian or in Japanese populations. Conversely, CYP2C19 * 2 allelic frequency (0.12), and genotype frequencies for GSTT1 null (0.11) and GSTM1 null (0.36) are lower than those observed in both populations. Finally, allele frequencies for CYP2A6 * 4(0.04), CYP2C8 * 3(0.06), CYP2C9 * 2(0.06), CYP2D6 * 4(0.12), CYP2E1 * 5B(0.14), CYP2E1 * 6(0.19), and UGT2B7 * 2(0.40) are intermediate in relation to those described in Caucasian and in Japanese populations, as expected according to the ethnic origin of the Chilean population. In conclusion, our findings support the idea that ethnic variability must be considered in the pharmacogenomic assessment of cancer pharmacotherapy, especially in mixed populations and for drugs with a narrow safety range.
Revista médica de Chile, 1996
We measured plasma concentrations of amiodarone and desethylamiodarone by HPLC in 44 outpatients ... more We measured plasma concentrations of amiodarone and desethylamiodarone by HPLC in 44 outpatients aged 24 to 67 years old (21 male), receiving the drug during at least three months. The drug was indicated for supraventricular arrhythmias in 37 patients and ventricular arrhythmias in seven. Plasma concentrations of amiodarone, desethylamiodarone and their ratio were 1.71 +/- 0.82, 0.85 +/- 0.42 micrograms/ml and 2.02 respectively, for a mean daily dose of 223 +/- 88 mg. In 41 patients, arrhytmias were successfully treated. These patients received a mean daily dose of 220 +/- 86 mg and concentrations of amiodarone, desethylamiodarone and their ratio were 1.75 +/- 0.86, 0.88 +/- 0.45 micrograms/ml and 1.99 respectively. In three patients with treatment failure, receiving a daily dose of 257 +/- 115 mg, these figures were 1.2 +/- 0.3, 0.5 +/- 0.1 micrograms/ml and 2.4 respectively. We conclude that our patients had lower plasma concentrations of desethylamiodarone and higher amiodarone/d...
Rev Chil Cardiol, Jun 1, 2006
Revista Medica De Chile, Apr 1, 2006
Revista Medica De Chile, Jun 1, 2003
Bioavailability of a particular drug can vary according to the formulation used. Therefore, studi... more Bioavailability of a particular drug can vary according to the formulation used. Therefore, studies of comparative bioavailability of different formulations of a same drug are worthwhile. To compare the bioavailability of two risperidone formulations available in the Chilean market. The bioavailability of a local risperidone formulation (Spiron) was compared with the original formulation of the drug (Risperdal) in 12 healthy volunteers, aged 19 +/- 1 years. A single dose of 3 mg was given orally, using a randomized double blind protocol in two periods. Fifteen blood samples were obtained at regular intervals, until 24 h after drug administration. Risperidone plasma levels were measured by high pressure liquid chromatography. pharmacokinetic parameters were calculated using a computer program that is independent of compartmental analysis. The area under the curve of plasma concentration versus time, from 0 to infinite (ABC0-infinity) and from 0 to 24 h (ABC0-24), early exposure (ABC from 0 to maximal time) and maximal plasma concentrations were significantly lower for Spiron. Half life time and time to achieve the maximal concentration were similar for the two formulations. According to bioequivalence tests suggested by the Food and Drug Administration (FDA) of the United States (90% confidence interval for the difference of long transformed mean pharmacokinetic parameters), the formulations Risperdal and Spiron, cannot be considered interchangeable.
Biomedica Revista Del Instituto Nacional De Salud, Jun 14, 2012
Introduction.Levonorgestrel a synthetic progestagen used for endometriosis, dysmenorrhea and emer... more Introduction.Levonorgestrel a synthetic progestagen used for endometriosis, dysmenorrhea and emergency contraception, is quickly and completely absorbed in the digestive tract. levonorgestrel is predominantly metabolised through hepatic routes that utilise the CYP3A system (CYP3A4 and CYP3A5).
Biomédica : revista del Instituto Nacional de Salud
Levonorgestrel a synthetic progestagen used for endometriosis, dysmenorrhea and emergency contrac... more Levonorgestrel a synthetic progestagen used for endometriosis, dysmenorrhea and emergency contraception, is quickly and completely absorbed in the digestive tract. levonorgestrel is predominantly metabolised through hepatic routes that utilise the CYP3A system (CYP3A4 and CYP3A5). This study aimed to evaluate the association between variant alleles of CYP3A4*1B and CYP3A5*3 polymorphisms and the pharmacokinetics of levonorgestrel. A group of 17 adult female healthy volunteers who signed an informed consent were genotyped for CYP3A4 and CYP3A5 through PCR-RFLP. Volunteers were submitted to pharmacokinetic analysis where, after a 12-hour overnight fast, they received a single oral dose of 0.75 mg of levonorgestrel. Serial blood samples were obtained (0 to 24 hours), and levonorgestrel concentrations were determined by UPLC-MS/MS to determine pharmacokinetic parameters. The procedures employed herein were performed according to the Declaration of Helsinki and Good Clinical Practices st...
Oncology letters, 2010
Polycyclic aromatic hydrocarbons (PAHs) contained in tobacco smoke acquire carcinogenicity follow... more Polycyclic aromatic hydrocarbons (PAHs) contained in tobacco smoke acquire carcinogenicity following their activation by xenobiotic-metabolizing enzymes to highly reactive metabolites. The cytochrome P4501A1 (CYP1A1) enzyme is central to the metabolic activation of these PAHs, and GSTM1 is the main enzyme responsible for its detoxification. CYP1A1 and GSTM1 polymorphisms were evaluated in 124 Chilean healthy controls and 48 oral cancer patients through PCR-based restriction fragment length polymorphism. In the healthy controls, frequencies of the CYP1A1 variant alleles for m1 (CYP1A1(*)2A) and the GSTM1null genotype were found to be 0.25 and 0.19, respectively. In the oral cancer patients, these frequencies were 0.33 and 0.50, respectively. Thus, the GSTM1 and m1 rare alleles were significantly more frequent in the oral cancer patients compared to the controls. The estimated relative risk for oral cancer associated with the single genotype CYP1A1 or GSTM1 was 2.08 for wt/m1, 1.04 fo...
Comparative Biochemistry and Physiology, 1969
... 6, 9). However, after 15 days, the heavier component is essentially lost when 280 MAR LUISA D... more ... 6, 9). However, after 15 days, the heavier component is essentially lost when 280 MAR LUISA DINAMARCA, IVAN SAAVEDRA AND ELENA VALD GSH is not present. ... DISCUSSION Lipke & Kearns (1959a, b) achieved a purification of DDT-dehydrochlorinase of about 570-fold. ...
Therapeutic drug monitoring, 2004
The objective of this study was to evaluate a possible pharmacokinetic interaction between 17beta... more The objective of this study was to evaluate a possible pharmacokinetic interaction between 17beta-estradiol (E2) and medroxyprogesterone (MP) when administered together in a combined tablet because both hormones have common metabolic routes of biotransformation. The study assessed the mean pharmacokinetics parameters of E2 found after 1-dose administration of 2 different tablets containing E2, 1 containing 2 mg of micronized 17beta-estradiol valerate (E2V) and the other, administered after 2 weeks, 2 mg of E2V in combination with 5 mg of medroxyprogesterone acetate (MPA). The subjects were 15 healthy postmenopausal women with normal laboratory and clinic tests. The study was randomized, double blind, crossover, with 2 periods and 2 sequences. The blood samples were obtained at 0, 1, 2, 3, 4, 6, 8, 10, 12, and 24 hours after each administration. The E2 serum concentrations were determined by electrochemoluminiscence assay. From these data, the following pharmacokinetic parameters wer...
Biomédica, 2012
Introduction.Levonorgestrel a synthetic progestagen used for endometriosis, dysmenorrhea and emer... more Introduction.Levonorgestrel a synthetic progestagen used for endometriosis, dysmenorrhea and emergency contraception, is quickly and completely absorbed in the digestive tract. levonorgestrel is predominantly metabolised through hepatic routes that utilise the CYP3A system (CYP3A4 and CYP3A5).
Revista chilena de cardiología, 2011
Determinación del polimorfismo de CYP2C9*2 y su relación con la farmacocinética de acenocumarol e... more Determinación del polimorfismo de CYP2C9*2 y su relación con la farmacocinética de acenocumarol en voluntarios sanos.
Revista médica de Chile, 2006
Revista chilena de infectología, 2003
... de utilizar indistintamente una formulación u otra, disponiendo de elementos de juicio sufici... more ... de utilizar indistintamente una formulación u otra, disponiendo de elementos de juicio suficientes para ... La claritromicina es un antimicrobiano macrólido de segunda generación, derivado semisintético de la ... C máx ) entre una y dos horas después de la administración oral. ...
Therapeutic Drug Monitoring, 1985
An interaction between phenytoin (PHT) and clonazepam (CZP) occurred in an epileptic patient, who... more An interaction between phenytoin (PHT) and clonazepam (CZP) occurred in an epileptic patient, who had been treated with PHT with partial seizure control. The addition of CZP brought about a significant decrease of PHT plasma levels (from 24.8 to 16 micrograms/ml) in spite of increases in the PHT dose. Gradual reduction of CZP, without modifying the PHT dosage, caused significant increases in PHT plasma levels to 42.4 micrograms/ml with signs of intoxication. A review of the literature shows contradictions: some authors state that there is no interaction between the drugs; other authors state either an increase or decrease in PHT plasma levels. These paradoxical results could be explained by the bidirectional effect of these drugs in hepatic enzyme metabolism. The importance of monitoring plasma levels of antiepileptic drugs is emphasized when several medications are required in the treatment of epilepsy.
Journal of Hydraulic Research, 1999
Résumé/Abstract On présente dans cet article un modèle bidimensionnal aux éléments finis pour la ... more Résumé/Abstract On présente dans cet article un modèle bidimensionnal aux éléments finis pour la simulation du transport de sédiments en suspension en zone côtière. Le modèle consiste en un modèle hydrodynamique, plus un modèle de convection-diffusion ...
Epilepsia, 1980
In a prospective study of 117 adult ambulatory patients, 110 of whom were epileptics treated only... more In a prospective study of 117 adult ambulatory patients, 110 of whom were epileptics treated only with oral diphenylhydantoin (DPH), plasma levels of this drug were determined by gas-liquid chromatography. The average follow-up time was 6 months (range, 3 to 13 months); satisfactory control of seizures was obtained with plasma levels in the 10.2 to 25.8 micrograms/ml range, representing 68% of the patients whose seizures had been controlled. The dosage received by this group was from 4.2 to 6 mg/kg, with an average of 5.1. In general, these results agree with those found in European or North American patients, even though some differences or little clarity in the methodology of other trials make comparison difficult. This similarity of results makes one think that genetic or environmental differences do not alter the response to DPH in our patients, but further studies are necessary in that area. This paper can serve as a basis for the extrapolation of data about DPH coming from other latitudes that have been considered supposedly valid for Latin American epileptic patients.
Frontiers in Genetics, 2012
Cancer is a leading cause of death worldwide. The cancer incidence rate in Chile is 133.7/100,000... more Cancer is a leading cause of death worldwide. The cancer incidence rate in Chile is 133.7/100,000 inhabitants and it is the second cause of death, after cardiovascular diseases. Most of the antineoplastic drugs are metabolized to be detoxified, and some of them to be activated. Genetic polymorphisms of drug-metabolizing enzymes can induce deep changes in enzyme activity, leading to individual variability in drug efficacy and/or toxicity. The present research describes the presence of genetic polymorphisms in the Chilean population, which might be useful in public health programs for personalized treatment of cancer, and compares these frequencies with those reported for Asian and Caucasian populations, as a contribution to the evaluation of ethnic differences in the response to chemotherapy. We analyzed 23 polymorphisms in a group of 253 unrelated Chilean volunteers from the general population. The results showed that CYP2A6 * 2, CYP2A6 * 3, CYP2D6 * 3, CYP2C19 * 3, and CYP3A4 * 17 variant alleles are virtually absent in Chileans. CYP1A1 * 2A allele frequency (0.37) is similar to that of Caucasians and higher than that reported for Japanese people. Allele frequencies for CYP3A5 * 3(0.76) and CYP2C9 * 3(0.04) are similar to those observed in Japanese people. CYP1A1 * 2C(0.32), CYP1A2 * 1F (0.77), CYP3A4 * 1B(0.06), CYP2D6 * 2(0.41), and MTHFR T(0.52) allele frequencies are higher than the observed either in Caucasian or in Japanese populations. Conversely, CYP2C19 * 2 allelic frequency (0.12), and genotype frequencies for GSTT1 null (0.11) and GSTM1 null (0.36) are lower than those observed in both populations. Finally, allele frequencies for CYP2A6 * 4(0.04), CYP2C8 * 3(0.06), CYP2C9 * 2(0.06), CYP2D6 * 4(0.12), CYP2E1 * 5B(0.14), CYP2E1 * 6(0.19), and UGT2B7 * 2(0.40) are intermediate in relation to those described in Caucasian and in Japanese populations, as expected according to the ethnic origin of the Chilean population. In conclusion, our findings support the idea that ethnic variability must be considered in the pharmacogenomic assessment of cancer pharmacotherapy, especially in mixed populations and for drugs with a narrow safety range.