The primary cause of death in Europe and the rest of the world continues to be cardiovascular diseases (CVD). According to the Global Burden of Disease study, cardiovascular disease (CVD) caused 29.6% of all deaths worldwide in 2010 (15.6 million deaths), more than all communicable diseases, maternal, neonatal, and nutritional disorders combined, and twice as many deaths as cancers. Although the number of diagnosed cases of CVD, and particularly coronary heart disease (CHD), has been steadily increasing, there is undeniable evidence from the majority of the countries with data that the mortality and case-fatality rates from CHD and stroke have significantly declined over the last 5–10 years, though at varying rates. While several countries in Eastern Europe, including Russia, Ukraine, and Lithuania, have shown little indication of such trends, the number of CVD-related deaths has significantly decreased in western European nations. These patterns suggest that the improvements in healthcare quality related to medication-based treatment and risk factor control may be the source of the divergent changes in CVD-related hospitalizations and CVD-related mortality. The administration of CVD medications based on pharmacogenomics may help further reduce the number of CVD-related deaths and adverse drug reactions, which were recorded almost five times more frequently in Lithuania between 2007 and 2015. The response to pharmacologic medications used to treat CVD varies greatly between individuals. When the same therapeutic dose is given to two patients with similar age and weight, plasma drug levels can vary by orders of magnitude. However, genetic factors are also very likely to play a significant role, especially in the case of non-inducible enzymes like CYP2D6. Drug-drug interactions, concurrent diseases, and ethnicity are just a few examples of environmental factors that can affect the variability in drug responses between patients. By examining the distribution patterns of allele and genotype frequencies of common and rare variants in the genes linked to pharmacological efficacy and adverse drug reactions, the goal of this study was to determine the pharmacogenomic idiosyncrasies of the Lithuanian population (ADR). Whole exome sequencing. The Agilent SureSelectXT Target Enrichment System, the Life Technologies TargetSeqTM Exome Enrichment System, and the Applied Biosystems 5500 SOLiDTM Sequencer without Exact Call Chemistry were used for the whole exome sequencing (WES) approach to analyse SNVs and minor indels (ECC). The methods provided by the kit vendors were optimised and used during the experiment. Important mutations may be discovered outside of the intended exonic regions using either exome sequencing system. As a result, the analysis included all discovered variations with enough coverage and quality ratings. Analysis of single nucleotide variations is total of 243,192 distinct SNVs were called in the 98 members of the Lithuanian population. In the exons of the genes that could be crucial for treating CVD, more than 300 distinct SNVs were identified. There were 148 synonymous and 184 non-synonymous exon variations identified. An additional 385 SNVs were found in the introns, including 28 in the 3' UTR and 11 in the 5' UTR area.