The AKR1D1*36 (rs1872930) Allelic Variant Is Independently Associated With Clopidogrel Treatment Outcome.

AIMS: The present observational cohort study evaluated the association between the AKR1D1*36 (rs1872930) allele and the risk of major adverse cardiovascular and cerebrovascular events (MACCE) in clopidogrel treated patients. METHODS: We screened 198 consecutive cardiovascular patients on clopidogrel therapy admitted in October to November 2010 with cardiovascular or cerebrovascular symptoms; of these 118 met the study protocol entry criteria; the median age of the cohort was 62.5 years (IQR 57-66 years), and 55% were females. RESULTS: The median follow up time was 38.5 (IQR 24-48) months; Kaplan-Meier/Log-rank analysis showed that patients carrying the AKR1D1*36 allelic variant have a shorter event-free-survival compared to wild type patients, hazard ratio = 2.193 (95% CI, 1.091 to 4.406); p = 0.0155. Multivariable Cox regression analysis confirmed the AKR1D1*36 allele as an independent risk factor (HR = 2.36; 95% CI, 1.34 to 4.18) and identified 3 other risk factors for MACCE; previous percutaneous interventions (PCI), HR = 2.78; (95% CI, 1.34 to 5.78), and a history of myocardial infarction, HR = 2.62; (95% CI, 1.48 to 4.64) at baseline and the previously reported CYP2C19*2 polymorphism (HR = 2.33; 95% CI, 1.33 to 4.06). CONCLUSION: The AKR1D1*36 (rs1872930) variant is independently associated with a higher risk for MACCE and shorter event-free survival time.

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.

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 AUC0-t and 0-∞, high Cltot and short tmax 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.

Cost-effectiveness analysis of treating transplant-eligible multiple myeloma patients in Macedonia.

PURPOSE: A decision-analytic model was developed to study the impact of induction regimens vincristine, adriamycin, dexamethasone (VAD); thalidomide, dexamethasone (TD); and bortezomib, dexamethasone (BorD), followed by autologous stem cell transplantation (ASCT) for treating multiple myeloma (MM) patients in Macedonia. Additionally, a cost-effectiveness analysis (CEA) of treatment sequences to predict health effects and costs of different treatment sequences was performed. METHODS: Model strategies were based on a previously published study for treating patients with MM in Macedonia. The data on disease progression and treatment effectiveness were obtained from the published reports of randomized clinical trials (GIMEMA M-B02005, IFM 2005-01). Utility parameters were extracted from the literature. To compare treatment combinations, a decision tree model was developed. Additionally, a cost analysis for one-time per-protocol costs was performed from a Macedonian national health care perspective. The incremental cost-effectiveness ratios (ICERs)/quality-adjusted life years (QALYs) gained for 1-, 10-, and 20-year time horizons were determined. Costs and health outcomes were discounted to evaluate the effects of time in the model. RESULTS: The one-time costs of BorD (EUR 5,656) were higher compared to VAD (EUR 303) and TD (EUR 329), increasing the overall costs for BorD. Thus, the BorD combination dominated in the baseline results (1 and 10 years) and the ICER for TD vs. VAD was EUR 7,564/QALY (20 years, undiscounted model). However, in the discounted 20-year model, BorD showed an ICER of EUR 138,747/QALY gained for BorD vs. TD. CONCLUSION: The CEA performed indicated that considering 1-year time horizon costs, VAD may be a cost-effective alternative vs. TD or BorD. However, for the longer period (10 or 20 years) including the discounting of future costs and outcomes, the TD and BorD combinations showed higher health benefits in terms of QALYs and more cost-effective vs. VAD. These results should be considered as supportive evidence by decision-makers and providers when deciding on the most cost-effective induction treatment strategy prior to ASCT in MM patients.

Evaluation of statin utilization in the Republic of Macedonia during 2013-2016.

PURPOSE: A rational use of statins has a major and increasing importance in public health and allocation of financial resources by the health insurance funds (HIFs). The aim of this study was to evaluate the market share and utilization trends of statins in the Republic of Macedonia (R. Macedonia) from 2013 to 2016. MATERIALS AND METHODS: A retrospective analysis and data comparison for the utilization of HMG-CoA inhibitors (C10AA) in R. Macedonia from 2013 to 2016 were conducted. The data obtained from HIF, IMS Health, pharmaceutical industry and marketing authorization holders (MAHs) were evaluated through defined daily doses per 1000 insurers per day (DDD/TID). RESULTS: Cardiovascular drugs are the most commonly prescribed and utilized drugs in R. Macedonia. The HIF cost for cardiovascular disease (CVD) increased to €2,243,777.00 in the period from 2013 to 2016. Since 2012, the reimbursement shows that atorvastatin accounts for the highest expenditure reaching €2,162,958.00 while rosuvastatin reached €1,645,860.00 in 2016. The increased consumption of statins is confirmed from the records obtained from IMS Health databases in the evaluated period in R. Macedonia suggesting increased expenditures with total growth of 35.65% reaching €4,421,280.24 in 2016. Evident growth of statin consumption is confirmed from the data obtained from the pharmaceutical industry and MAH. The statin use increased from 42.347 DDD/TID in 2013 to 71.697 DDD/TID in 2016, although it is lower in comparison to other European Union (EU) countries (1.1-2.5-fold). CONCLUSION: The rapid increase in the consumption of statins can be attributed mostly to an increase in the consumption volume. It is inevitable to widen the price reduction concept with initiatives that may control statin consumption amounts with measures such as educational programs for rational drug utilization and targeting eligible population.

Evaluation of Correlation Between the Pharmacogenetic Profiles of Risperidone Treated Psychiatry Patients with Plasma and Urine Concentration of Risperidone and its Active Moiety 9-OH Risperidone Determined with Optimized Bioanalytical LC Method.

Atypical antipsychotic risperidone is widely used first-line monotherapy in schizophrenia and combined therapy in bipolar disorders. Therapeutic plasma concentrations of risperidone and its active moiety are directly influenced by genetic variations in metabolic CYP450 enzymes (CYP2D6 and CYP3A4/5) and transporter (ABCB1) protein and additional environmental factors. Since active metabolite 9-OH risperidone has a greater percentage of the pharmacologically active fraction and is equipotent to the parent drug risperidone, it is assumed that it contributes significantly to therapeutic and adverse effects. Unpredictable dose/concentration ratio, narrow therapeutic index, number of interactions, along with serious adverse reactions (ADR), raises the need for individualization of risperidone treatment and establishing of good therapeutic regime using TDM. A simple and reliable validated bioanalytical liquide-liquide extraction HPLC/UV method was applied for the simultaneous determination of risperidone and its active metabolite, 9-OH risperidone, in human plasma and urine of 52 hospitalized schizophrenia/bipolar disorder patients treated with risperidone as monotherapy and in polytherapy. All the patients were previously genotyped for CYP2D6 (EM=30, EM/IM=14, IM=4 IM/PM=1 and PM=3) and ABCB1 using Real-Time PCR methods with TaqMan SNP genotyping suitable assays according to the guidelines of the manufacturer (Life Technologies, USA).The influence of CYP2D6 phenotype on metabolic ratio MR (Ris/9-OHRis) in plasma (p=0.012) and in urine (p=0.048) was confirmed. Statistically significant correlation (R2=55.53%, Rho=0.844, p<0,0001) for MR in both plasma and urine indicates that urine may be utilized as appropriate media for initial CYP2D6 phenotype identification and selection of patients on risperidone treatment with high risk for ADR.

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

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.

Biosimilar medical products - licensing, pharmacovigilance and interchangeability.

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.

Evaluation of reliability and validity of the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30, Albanian version) among breast cancer patients from Kosovo.

PATIENTS AND METHODS: A sample of breast cancer patients (n=62 women) were interviewed for the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) in Albanian. Reliability of the questionnaire was considered acceptable if Cronbach's alpha was ≥0.70. Item convergent-discriminant validity was tested through multitrait scaling analysis. Construct validity was tested under the hypotheses that QLQ-C30 interscale correlations would have an acceptable value of ≥0.40 and as well as by known group comparisons assessing differences of patient subgroups with reference to disease stage and education level. RESULTS: The mean age of the patients was 50 years (standard deviation: 10.9 years). Cronbach's alpha ranged from 0.54 for the cognitive functioning scale to 0.96 for the global health quality of life (GH/QoL) scale. In multitrait scaling analysis, the strength of Spearman's correlations between an item and its own subscale was ≥0.40, with the exception of item 5 (ρ=0.22); results for item discriminant validity were satisfactory, with the exception of item 5, which showed higher correlation with other subscales than with its own physical functioning. The Spearman's interscale coefficients generally were correlated with each other. Results of known group comparisons did not show significant differences in terms of disease stage. Regarding education level, patients with high school/university education had better functional scales scores only in certain subscales compared to other subgroups; furthermore, patients with secondary school education had better GH/QoL compared to other subgroups of patients. CONCLUSION: The EORTC QLQ-C30 (v3.0) in Albanian was found to be valid and reliable for women with breast cancer and could be considered as a starting point for further evaluation study.

Genotype variability and haplotype profile of ABCB1 (MDR1) gene polymorphisms in Macedonian population.

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.

Development and validation of a bioanalytical LC-UV method with solid-phase extraction for determination of valproic acid in saliva.

A bioanalytical HPLC method with UV detection for the determination of the antiepileptic drug valproic acid in human saliva has been developed and validated. Saliva represents an alternative matrix for therapeutic monitoring of antiepileptic drugs due to the increasing interest in free drug concentration. The proposed method involved solid-phase extraction for sample preparation and yielded very good mean recoveries of 99.4 % and 97.9 % for valproic acid and IS, respectively. The calibration function for valproic acid was linear over the concentration range of 1.0-50.0 µg mL⁻¹ (R² = 0.9989). Within-run and between-run precision and accuracy were studied at four concentrations and RSDs were less than 7.3 and 2.2 %, while accuracy values were higher than 96.8 and 97.5 %, respectively. The described method provides sensitivity, linearity, precision, accuracy and is suitable for analyses of valproic acid in saliva samples.

Does brain slices from pentylenetetrazole-kindled mice provide a more predictive screening model for antiepileptic drugs?

The cortical wedge is a commonly applied model for in vitro screening of new antiepileptic drugs (AEDs) and has been extensively used in characterization of well-known AEDs. However, the predictive validity of this model as a screening model has been questioned as, e.g., carbamazepine has been reported to lack effect in this model. The neuroplastic changes induced in acute and chronic animal models of epilepsy are known to affect the pharmacological profile of AEDs in vivo. Hence, we investigated whether brain slices from pentylenetetrazole (PTZ)-kindled animals could provide a more predictive screening model for AEDs. To this end, we compared the in vitro and in vivo pharmacological profile of several selected AEDs (phenobarbital, phenytoin, tiagabine, fosphenytoin, valproate, and carbamazepine) along with citalopram using the PTZ-kindled model and brain slices from naïve, saline-injected and PTZ-kindled mice. Our data suggest that the use of slices from PTZ-kindled mice in the cortical wedge does not increase the predictive validity of the model as an in vitro screening model for AEDs. Traditionally, the incidence of certain seizure types is widely used as a measure to characterize drug action in animal models of epilepsy. In our study, the anticonvulsant effect of the AEDs was investigated in vivo using several observational parameters (i.e., incidence and duration of convulsions, latency to clonic convulsions, and severity of convulsions). We found that including the observational parameter "severity" offered important additional information about the drug profile that would otherwise be lost if only a single parameter as "incidence" was used.

The association of C3435T single-nucleotide polymorphism, Pgp-glycoprotein gene expression levels and carbamazepine maintenance dose in patients with epilepsy.

The ABCB1 gene encodes the P-glycoprotein (Pgp) protein, which is thought to transport various antiepileptic drugs. The single nucleotide polymorphism (SNP) (C3435T) in exon 26 of this gene correlates with the altered expression levels of P-glycoprotein, range of drug response and clinical conditions. In order to investigate the influence of this polymorphism on the susceptibility to and efficacy of carbamazepine therapy, we evaluated the allelic frequency and genotype distribution of this variant in 162 epilepsy patients from the Republic of Macedonia. Statistically significant differences were detected neither in the allelic frequency and genotype distribution between carbamazepine-resistant and carbamazepine-responsive epilepsy patients nor between the subgroups of carbamazepine (CBZ)-responsive patients treated with different CBZ doses. However, the T-allele was enriched in CBZ-responsive patients who required higher maintenance CBZ doses, This observation was substantiated by the findings that the median total plasma levels were the lowest in patients with CC (20 µmol/L) followed by CT (23 µmol/L) and TT (29 µmol/L) genotypes. Patients with a CC genotype also had a higher likelihood of response compared to patients with CT or TT genotypes over a wide range (400-1000 mg/day) of initial doses of CBZ. The T allele showed a reduced expression of ~5% compared to the C allele in peripheral blood mononuclear cells in heterozygotes for the variant. This difference might be translated into ~10% difference in homozygotes for the variant, which would explain the trend towards a dose-dependent efficacy of the CBZ treatment in patients with different genotypes. A larger prospective study is warranted to clarify the clinical utility of a genotypespecific individualized CBZ therapy.