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  • Author: Aleksandar Dimovski x
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Genetic polymorphisms of CYP2C9, CYP2C19, and CYP3A5 in Kosovar population

Abstract

Cytochrome P450 genetic polymorphisms are responsible for individual variations in drug metabolism and drug-drug interactions. They are very important for pharmacogenetics, and their frequency varies across different populations. There is a big gap in the knowledge about the CYP gene family polymorphisms in the population of Kosovo, and the aim of our study was to fill that gap by determining the frequency of the most important variant alleles of CYP2C9, CYP2C19, and CYP3A5 in 234 nonrelated Kosovars. The allele frequencies of CYP2C9*2 and 2C9*3 were 17.52 %, and 10.89 %, respectively. Sixteen participants (6.81 %) were CYP2C9 poor metabolisers. The CYP2C19*2 and *17 variant frequencies were 13.03 % and 19.01 %, respectively. There were 2.13 % CYP2C19 poor and 4.27 % ultra-rapid metabolisers (homozygous carriers of the *17 allele). With regard to CYP3A5, the frequency of the *3 variant allele was 98.29 % (non-expressors), while the remaining participants (1.70 %) were expressors of CYP3A5. These findings are comparable with other European ethnicities, specifically those of Southeast Europe.

Open access
How polymorphisms of the cytochrome P450 genes affect ibuprofen and diclofenac metabolism and toxicity / Kako polimorfizmi gena citokroma P450 utječu na metabolizam i toksičnost ibuprofena i diklofenaka

Abstract

Interindividual variability in drug metabolism is an important cause of adverse drug reactions and variability in drug efficiency. Polymorphisms of cytochrome P450 (CYPs) genes have a significant effect on drug metabolism and toxicity. This review brings an update about how genetic polymorphisms of CYP2C8 and CYP2C9 enzymes affect the disposition and clinical outcomes of ibuprofen and diclofenac, two of the most common pain relievers. The most common side effects associated with the influence of CYP2C8*3 and CYP2C9*2*3 variants on ibuprofen and diclofenac pharmacokinetics are hepatotoxicity and gastrointestinal bleeding. CYP genotyping may therefore identify patients at increased risk of these adverse reactions, and these patients could have their doses adjusted or start receiving another NSAID that does not share the same metabolic pathways with ibuprofen or diclofenac. However, before genotyping is introduced into regular clinical practice, more research is needed to evaluate the effectiveness of this strategy in improving treatment with ibuprofen and diclofenac.

Open access
Biosimilar medical products – licensing, pharmacovigilance and interchangeability

Abstract

The use of biological medicine has significantly increased in recent decades and has made substantial contributions to improving the effectiveness of therapies in many diseases. The expiration of patents of biological innovative medicines enables copies of those drugs called similar biological products (biosimilars) to be approved by regulatory authorities and to enter in clinical use. Biosimilars are comparable but not identical and are not a generic version of the innovator biological product. Although biosimilars undergo rigorous characterization as well as clinical studies to prove their safety and effectiveness, specific regulatory requirements for registration apply in the case of biosimilars. They are highly complex molecules and small changes in the production process can have major implications in its safety and effectiveness profile. The availability of biosimilars enhances competition, with the potential to improve patient access to biological medicines and to contribute to the financial sustainability of healthcare systems. In order to be certain that a biosimilar reaches its potential in clinical use, an intensive pharmacovigilance monitoring system must be established in order to prove the true similarity between the original biologic and its biosimilar. There is a need for further guidance and resolution of the ongoing discussions on biosimilar labelling, naming, pharmacovigilance and substitution in order to ensure effective and appropriate use of biosimilars in clinical practice.

Open access
in PRILOZI
Pharmacogenetics and Antipsychotic Treatment Response/ Фармакогенетски Тестирања И Одговор Кон Третман Со Антипсихотоци

Abstract

Antipsychotic drugs are widely used in the treatment of schizophrenia and psychotic disorder. The lack of antipsychotic response and treatment-induced side-effects, such as neuroleptic syndrome, polydipsia, metabolic syndrome, weight gain, extrapyramidal symptoms, tardive dyskinesia or prolactin increase, are the two main reasons for non-compliance and increased morbidity in schizophrenic patients. During the past decades intensive research has been done in order to determine the influence of genetic variations on antipsychotics dosage, treatment efficacy and safety. The present work reviews the molecular basis of treatment response of schizophrenia. It highlights the most important findings about the impact of functional polymorphisms in genes coding the CYP450 metabolizing enzymes, ABCB1 transporter gene, dopaminergic and serotonergic drug targets (DRD2, DRD3, DRD4, 5-HT1, 5HT-2A, 5HT-2C, 5HT6) as well as genes responsible for metabolism of neurotransmitters and G signalling pathways (5-HTTLPR, BDNF, COMT, RGS4) and points their role as potential biomarkers in everyday clinical practice. Pharmacogenetic testing has predictive power in the selection of antipsychotic drugs and doses tailored according to the patient’s genetic profile. In this perception pharmacogenetics could help in the improvement of treatment response by using different medicinal approaches that would avoid potential adverse effects, reduce stabilization time and will advance the prognosis of schizophrenic patients.

Open access
in PRILOZI
Genotype Variability and Haplotype Profile of Abcb1 (Mdr1) Gene Polymorphisms in Macedonian Population

Abstract

The aim of this study was to evaluate the most common ABCB1 (MDR1, P-glycoprotein) polymorphisms in the population of R. Macedonia and compare the allele and haplotype frequencies with the global geographic data reported from different ethnic populations. The total of 107 healthy Macedonian individuals from the general population was included.

Genotypes for the ABCB1 for three polymorphisms C1236T [rs1128503], G2677A/T [rs2032582] and C3435T [rs1045642] were analyzed by Real-Time PCR. Obtained allele frequencies for these three SNPs were similar to those observed in other European Caucasians. The detected genotype frequencies were 33.6% for 1236CC, 44.9% for 1236CT and 21.5% for 1236TT in exon 12; 32.7%, 44.9% and 22.4% for 2677GG, 2677GT and 2677GT consecutively in exon 21; and 25.2% for 3435CC, 52.3% for 3435CT and 22.5% for 3435TT in exon 26. Strong LD was observed in our study among all three SNPs with the highest association confirmed for C1236T and G2677T ((D' = 0.859, r2 = 0.711). Eight different haplotypes were identified and the most prominent was the CGC haplotype (45.3%). Our study was the first to have documented the distribution of ABCB1 alleles, genotypes and haplotypes in the population of R. Macedonia. The obtained results can help in the prediction of different response to the drugs that are P-glycoprotein substrates. Additionally, in the era of individualized medicine the determination of the P-glycoprotein genotype might be a good predictive marker for determination of the subpopulations with higher risk to certain diseases.

Open access
in PRILOZI
Preliminary Results of Introducing the Method Multiparameter Flow Cytometry in Patients with Acute Leukemia in the Republic of Macedonia

Preliminary Results of Introducing the Method Multiparameter Flow Cytometry in Patients with Acute Leukemia in the Republic of Macedonia

Background. In this paper we present the initial results of introducing the method of multiparameter flow cytometry (MPF) in patients with acute leukemia in the Republic of Macedonia.

Aim. The aim of our study is to improve the diagnosis and management of acute leukemia, to establish the correct lineage assignment of the blast cells and to select effective treatment strategy for each single acute leukemia patient.

Material and methods. A total of 44 adult (>15 years) patients (from initially 45 tested) with acute leukemia who were consecutively admitted at the Clinic of Hematology-Skopje from January through June 2008, were enrolled in this study. The MPF was introduced for the first time in the Republic of Macedonia and was performed at the Institute for Immunobiology and Human Genetics, Faculty of Medicine-Skopje.

Results. Our results showed that morphology and cytochemistry established lineage in 39 of patients, but not in 5 cases that presented as acute leukemia, of which 4 were assigned as myeloid and in one nonhematopoietic malignancy was indicated. Furthermore immunophenotyping change the lineage assigned based on morphology and cytochemistry in one case from lymphoid to myeloid. Results from our study showed that routine immunophenotyping improved the diagnosis in 6 (13.3%) cases. The exact lineage assignment of the blasts cells guides to implementation of specific molecular analyses in some subtypes of acute leukemia and their further definition, which is essential for more appropriate single patient therapeutic decisions.

Conclusion. Our data support routine implementation of MPF in the diagnostic evaluation of acute leukemia.

Open access
Association of Single-Nucleotide Polymorhism C3435T in the ABCB1 Gene with Opioid Sensitivity in Treatment of Postoperative Pain

Abstract

Background: The minimal effective analgesic concentration of opioids required for satisfactory analgesia may differ significantly among the patients. Genetic factors may contribute to the variable response to opioids by affecting their pharmacokinetics or pharmacodynamics.

Methods: Ninety nine patients undergoing abdominal surgery with colorectal anastomosis because of colorectal carcinoma were enrolled in the present study. C34535T was genotyped in all subjects and the patients were divided into three groups according to their genotype: CC-wild type homozygous, CT-mutant heterozygous and TT-mutant homozygous. Intravenous fentanyl, patient controlled analgesia was provided postoperatively for pain control in the first 24 hour after surgery. Opioid consumption, pain scores and the adverse side effects were evaluated.

Results: Our main result is that the patients in the CC genotype group consumed significantly more fentanyl (375.0 μg ± 43.1) than the patients in the TT group (295.0 μg ± 49.1) and the CT (356.4 μg ± 41.8) group in the treatment of postoperative pain. The patients in the TT group had lower VAS scores at 6h, 12h, 18 h and 24h postoperatively. There were no significant differences in the side effects among the three groups regarding the vomiting and the sedation score. The patients in the TT group had more frequently nausea score 1, than the patients in the other two groups.

Conclusion: Our study indicates that the C3435T SNPs of the ABCB1 gene is associated with differences in the opioid sensitivity. The ABCB1 polymorphism may serve as an important genetic predictor to guide the acute pain therapy in postoperative patients.

Open access
in PRILOZI
Hydrazinyldiene-chroman-2,4-diones in inducing growth arrest and apoptosis in breast cancer cells: Synergism with doxorubicin and correlation with physicochemical properties

Abstract

This study evaluates the effects of previously synthesized hydrazinyldiene-chroman-2,4-diones on cell proliferation and apoptosis, cell cycle distribution and migration capacity of MCF-7 breast cancer cells in synergy with doxorubicin. Physicochemical properties of the synthesized compounds were correlated with their structure and activity. Significant cell viability decrease in comparison with the effect of doxorubicin alone and the reference 4-hydroxycoumarin was observed when combination treatment comprising doxorubicin and the title compounds was applied. Synergistic effect with doxorubicin was also observed in down-regulation of phospho-Thr308Akt levels, confirming reduced proliferation and increased apoptosis. Combined treatment increased the percentage of cells arrested at the G2/M stage. Additive inhibition of cell migration was also observed, pointing to the possibility of reducing the risk of metastases. With their solubility profile and log D7.4, all the synthesized compounds follow Lipinski’s rule of five for good permeability (absorption) potential.

Open access
Evaluation of the Role of ABCB1gene Polymorphic Variants on Psychiatric Disorders Predisposition in Macedonian Population

Abstract

The psychiatric and other CNS disorders are characterized with unregulated neuro-inflammatory processes and chronic microglia cell activation resulting with detrimental effect. ABCB1gene polymorphismsC1236T, G2677T/Aand C3435T are associated with P-glycoprotein expression and function andare linked with predisposition to psychiatric disorders such as schizophrenia and bipolar disorders. The relationship between mood disorders and glucocorticoids has been confirmed and ABCB1 SNPs influence the glucocorticoids access to the brain.

The aim of the study is evaluation of the influence of the three most common ABCB1SNPs on predisposition to psychiatric disorders in Macedonian population.

In the study 107 unrelated healthy Macedonians of both sexes were enrolled as a control group and patient population of 54 patients (22 to 65 years old) diagnosed with schizophrenia or bipolar disorder. ABCB1 for three polymorphisms were analyzed by Real-Time PCR in both groups.

The results have confirmed the role of the ABCB1 gene in predisposition to psychiatric disorders and increased risk of developing bipolar disorder in carriers of the heterozygotes and mutant homozygotes for polymorphic variations in 1236 and 2677 in comparison to the normal genotype carriers. Three-fold higher risk was estimated for psychiatric illness in women that are 1236 and 2677 heterozygous carrier (heterozygous and mutant homozygous) compared to healthy control (men and women) population and four-fold higher risk in comparison only to healthy women population. Mutant allele carriers for 1236 and 2677 polymorphisms that are 35 years and below in patients population have almost three-fold higher risk for development of psychiatric illness.

Open access
in PRILOZI
AKR1D1*36 C>T (rs1872930) allelic variant is associated with variability of the CYP2C9 genotype predicted pharmacokinetics of ibuprofen enantiomers – a pilot study in healthy volunteers

Abstract

The relative contribution of CYP2C9 allelic variants to the pharmacokinetics (PK) of ibuprofen (IBP) enantiomers has been studied extensively, but the potential clinical benefit of pharmacogenetically guided IBP treatment is not evident yet. The role of AKR1D1*36C>T (rs 1872930) allelic variant in interindividual variability of CYP450 mediated drug metabolism was recently elucidated. A total of 27 healthy male subjects, volunteers in IBP single-dose two-way cross-over bioequivalence studies were genotyped for CYP2C9*2, CYP2C9*3 and AKR1D1*36 polymorphisms. The correlation between CYP2C9 and AKR1D1 genetic profile and the PK parameters for S-(+) and R-(−)-IBP was evaluated. Remarkable changes in the PK values pointing to reduced CYP2C9 enzyme activity were detected only in the CYP2C9*2 allelic variant carriers. Statistically significant association between the AKR1D1*36 allele and the increased IBP metabolism (low AUC 0-t and 0–∞, high Cl tot and short t max values for both enantiomers) was observed in subjects carrying the CYP2C9 *1/*3 or CYP2C9*1/*1 genotype. The clinical value of concomitant CYP2C9 and AKR1D1 genotyping has to be further verified.

Open access