Impact of the Omics-Based Biomarkers on the Mirtazapine's Steady-State Concentration, Efficacy and Safety in Patients with Affective Disorders Comorbid with Alcohol Use Disorder.

Introduction: Mirtazapine is commonly administered to patients with recurrent depressive disorder. Some of these patients do not show adequate response to the therapy with mirtazapine, whereas many of them experience dose-dependent adverse drug reactions. Previous research revealed that CYP2D6 is involved in the metabolism of mirtazapine, the activity of which is highly dependent on the polymorphism of the gene encoding it.

Objective: The objective of this study was to investigate the effect of polymorphisms of the , , , , , , and genes on the concentration/dose indicator of mirtazapine and on the CYP3A expression level obtained by measuring the plasma concentration levels in patients suffering from a recurrent depressive disorder.

Material And Methods: Our study included 108 patients with recurrent depressive disorder (average age - 35.2 ± 15.1 years). The treatment regimen included mirtazapine in an average daily dose of 45.0 [30.0; 60.0] mg per week. Therapy efficacy was assessed using the international psychometric scales. Therapy safety was assessed using the UKU Side-Effect Rating Scale. For genotyping and estimation of the microRNA (miRNA) plasma levels, we performed the real-time polymerase chain reaction. The activity of CYP3A was evaluated using the HPLC-MS/MS method by the content of the endogenous substrate of the given isoenzyme and its metabolite in urine (6b-HC/cortisol). Therapeutic drug monitoring has been performed using HPLC-MS/MS.

Results: Our study didn't reveal any statistically significant results in terms of the treatment efficacy and safety of the therapy. We also didn't reveal a statistical significance for the concentration/dose indicator of mirtazapine in patients with different genotypes. Analysis of the results of the pharmacotranscriptomic part of the study didn't demonstrate the statistically significant difference in the plasma levels in patients with different genotypes. At the same time, correlation analysis didn't reveal a statistically significant relationship between the mirtazapine efficacy profile evaluated by changes in HAMD scale scores and the plasma concentration: rs = -0.2, p = 0.46. Also, we didn't reveal the correlation between the miRNA concentration and safety profile: rs = 0.029, p = 0.93. In addition, we didn't reveal the relationship between the CYP3A enzymatic activity and the plasma concentration: rs = -0,188, p = 0.85. However, the difference in the CYP3A enzymatic activity in carriers of and genotypes of the > polymorphism of gene has been revealed: () 4.75 [1.28; 7.34] vs () 8.83 [4.73; 13.62], p-value = 0.023.

Conclusion: Thus, the effect of genetic polymorphism of the CYP3A4, CYP2C9, CYP2C9, CYP3A5, ABCB1, CYP2C19, CYP2C19, CYP2C19, SCL6A4, 5-HTR2A gene on the efficacy and safety profiles of mirtazapine was not demonstrated in a group of 108 patients with depressive disorder and alcohol use disorder.