Clopidogrel, an oral platelet P2Y12 receptor blocker, is used in the treatment of acute coronary syndrome. Interindividual variability in treatment response and the occurrence of adverse effects has been attributed to genetic variants in CYP2C19. The analysis of relevant pharmacogenes in ethnically heterogeneous and poorly studied populations contributes to the implementation of personalized medicine. We analyzed the coding and regulatory regions of CYP2C19 in 166 patients with acute coronary syndrome (ACS) treated with clopidogrel. The allele frequencies of CYP2C19 alleles *1, *2, *4, *17, *27 and *33 alleles were 86.1%, 7.2%, 0.3%, 10.2%, 0.3% and 0.3%, respectively. A new potentially pathogenic mutation (p.L15H) and five intronic variants with potential splicing effects were detected. In 14.4% of the patients, a new haplotype in strong linkage disequilibrium was identified. The clinical outcome indicated that 13.5% of the patients presented adverse drugs reactions with a predominance of bleeding while 25% of these patients were carriers of at least one polymorphic allele. We propose that new regulatory single-nucleotide variants (SNVs) might potentially influence the response to clopidogrel in Colombian individuals.

In genes related to drug pharmacokinetics, molecular variations determine interindividual variability in the therapeutic efficacy and adverse drug reactions. The assessment of single-nucleotide variants (SNVs) is used with growing frequency in pharmacogenetic practice, and recently, high-throughput genomic analyses obtained through next-generation sequencing (NGS) have been recognized as powerful tools to identify common, rare and novel variants. These genetic profiles remain underexplored in Latin-American populations, including Colombia. In this study, we investigated the variability of 35 genes included in the ADME core panel (absorption, distribution, metabolism, and excretion) by whole-exome sequencing (WES) of 509 unrelated Colombian individuals with no previous reports of adverse drug reactions. Rare variants were filtered according to the minor allele frequencies (MAF) <1% and potential deleterious consequences. The functional impact of novel and rare missense variants was assessed using an optimized framework for pharmacogenetic variants. Bioinformatic analyses included the identification of clinically validated variants described in PharmGKB and ClinVar databases. Ancestry from WES data was inferred using the R package EthSEQ v2.1.4. Allelic frequencies were compared to other populations reported in the public gnomAD database. Our analysis revealed that rare missense pharmacogenetic variants were 2.1 times more frequent than common variants with 121 variants predicted as potentially deleterious. Rare loss of function (LoF) variants were identified in 65.7% of evaluated genes. Regarding variants with clinical pharmacogenetic effect, our study revealed 89 sequence variations in 28 genes represented by missense (62%), synonymous (22.5%), splice site (11.2%), and indels (3.4%). In this group, ABCB1, ABCC2, CY2B6, CYP2D6, DPYD, NAT2, SLC22A1, and UGTB2B7, are the most polymorphic genes. NAT2, CYP2B6 and DPYD metabolizer phenotypes demonstrated the highest variability. Ancestry analysis indicated admixture in 73% of the population. Allelic frequencies exhibit significant differences with other Latin-American populations, highlighting the importance of pharmacogenomic studies in populations of different ethnicities. Altogether, our data revealed that rare variants are an important source of variability in pharmacogenes involved in the pharmacokinetics of drugs and likely account for the unexplained interindividual variability in drug response. These findings provide evidence of the utility of WES for pharmacogenomic testing and into clinical practice.

Background: Copy Number variation (CNVs) in genes related to drug absorption, distribution, metabolism and excretion (ADME) are relevant in the interindividual variability of drug response. Studies of the CNVs in ADME genes in Latin America population are lacking. The objective of the study was to identify the genetic variability of CNVs in CYP-450 and GST genes in a subgroup of individuals of Colombian origin. Methods: Genomic DNA was isolated from 123 healthy individuals from a Colombian population. Multiplex Ligation-Dependent Probe Amplification (MLPA) was performed for the identification of CNVs in 40 genomic regions of 11 CYP-450 and 3 GST genes. The genetic variability, allelic and genotypic frequencies were analyzed. Results: We found that 13 out of 14 genes had CNVs: 5 (35.7%) exhibited deletions and duplications, while 8 (57.1%) presented either deletions or duplications.. 33.3% of individuals carried deletions and duplications while 49.6% had a unique type of CNV (deletion or duplication). The allelic frequencies of the CYP and GST genes were 0 to 47.6% (allele null), 0 to 17.5% (duplicated alleles) and 37 to 100% (normal alleles). Conclusions: Our results describe, for the first time, the genomic profile of CNVs in a subgroup of Colombian population in GST and CYP-450 genes. GST genes indicated greater genetic variability than CYP-450 genes. The data obtained contributes to the knowledge of genetic profiles in Latin American subgroups. Although the clinical relevance of CNVs has not been fully established, it is a valuable source of pharmacogenetic variability data with potential involvement in the response to medications.

Background: The COVID-19 pandemic has led to an increase in the behavior of self-medication (SM). Given the massive release of misleading information during the pandemic, some pharmacies recommend drugs such as ivermectin, azithromycin, and hydroxychloroquine that are not useful for preventing or treating COVID-19 and could expose patients to unnecessary adverse drug reactions (ADRs), drug-drug interactions (DDIs), disease masking, and antibiotic resistance. Rationale: SM with drugs advertised for COVID-19 can have consequences, and people should be aware of approved uses, potential contraindications, and ADRs. Thus, the aim of this study was to know the drug therapies including natural products and homeopathic drugs offered by Colombian pharmaceutical establishments for the prevention and treatment of COVID-19, as well as the information provided on the safe use of the product. Methods: An observational, cross-sectional mystery shopping study was carried out to determine the pharmaceutical alternatives for the management of COVID-19 offered by pharmaceutical establishments (drugstores, pharmacies, homeopathic pharmacies, and nutritional supplements stores) in Colombia, and information related to the safe use of the product. The study included 482 pharmaceutical establishments from 16 Colombian departments. Data collection was done through telephone calls to each of the establishments following an interview protocol pretending to be a patient who presents symptoms related to COVID-19. Results: About 57.3% (276) of the establishments recommended a product for the treatment of COVID-19 infection, 66.6% (321) asked whether the caller had COVID-19 symptoms and what they are, and 44.2% (213) suggested taking a COVID-19 test. Of 59 drugs suggested by pharmacies, the most recommended were azithromycin, ivermectin, acetaminophen, ibuprofen, and ASA (aspirin). From the establishments that recommended a product, dosage was indicated in 85.5% (236) of the pharmaceutical establishments and 14.5% (40) of the establishments reported the most common adverse effects of this substance. About 9.4% (26) of the establishments reported possible interactions of the recommended drugs and substances with food, beverages, or supplements.Conclusion: Pharmaceutical establishments in Colombia seem to have significantly contributed to self-medication for COVID-19 in Colombia during the pandemic. This behavior is inappropriate, since the mild forms of the disease do not have a specific treatment. Plain Language Summary Self-medication induced by pharmaceutical establishments in Colombia during the COVID-19 pandemic Background: The COVID-19 pandemic has led to an increase in the behavior of self-medication (SM). Given the massive release of misleading information during the pandemic, some pharmacies recommend drugs such as ivermectin, azithromycin, hydroxychloroquine among others, which are not useful for preventing or treating COVID-19 and could expose patients to unnecessary side effects and interactions with other medications. People should be aware of the approved and non-approved uses, and potential side effects of these drugs. Rationale: The aim of this study was to know the drugs, including natural products and homeopathic drugs, offered by Colombian pharmaceutical establishments for the prevention and treatment of COVID-19, as well as the information provided on the safe use of the product. Methods: The study was done using the mystery shopping method, collecting data through telephone calls to each of the establishments by a trained individual pretending to be a patient with COVID-19 symptoms. The study included 482 pharmaceutical establishments from 16 Colombian departments. Results: Of 59 drugs suggested by pharmacies, the most recommended were azithromycin, ivermectin, acetaminophen, ibuprofen, and aspirin. The recommended dose was indicated in 85.5% (236) of the pharmaceutical establishments, and 14.5% (40) of them reported the most common adverse effects of the recommended product. About 9.4% (26) of the establishments reported possible interactions of the recommended drugs and substances with food, beverages, or supplements. Conclusion: The majority of the pharmaceutical establishments included in the study promoted inadequate self-medication for COVID-19 in Colombia during the pandemic.