The clinical pharmacogenetics implementation consortium guideline for SLCO1B1 and simvastatin-induced myopathy: 2014 update

The Use of Pharmacogenomics in Cardiovascular Care

Pharmacogenomics (PGx)-the study of how one's genes affect their response to drugs-has implications for every medical subspecialty, including cardiology. This article discusses evidence-based resources that provide guidance for interpreting and applying PGx results in patient care. All health care providers, including frontline nurses, should understand this important tool for patient care.

SLCO1B1 Functional Variants, Bilirubin, Statin-Induced Myotoxicity, and Recent Sub-Saharan African Ancestry: A Precision Medicine Health Equity Study

Statin pharmacogenetic implementation guidelines are derived from evidence of primarily Eurocentrically biased study populations. Functional SLCO1B1 variants that are rare in these study populations have not been equitably investigated and are thus missing from guidelines. The objective of this precision medicine health equity study was to determine the clinical validity of understudied candidate functional SLCO1B1 variants common in people with 1,000 Genomes sub-Saharan African superpopulation (1KG-AFR-like) genetic similarity. We conducted our analyses using the real-world evidence of participants from three large, electronic health record-linked biobanks. We used bilirubin levels (as an endogenous substrate of organic anion transporting polypeptide [OATP1B1] function) and severe statin-induced myotoxicity phenotypes. Loss-of-function splice variant rs77271279 (P = 1.1 × 10-17) had the strongest association with elevated total bilirubin levels in Black participants (mean 84% AFR-like genetic similarity) followed by missense variant rs59502379 (P = 7.4 × 10-12) then missense variant rs4149056 (P = 6.0 × 10-5). In an exploratory subset of the Black study population who used statins (n = 77 severe statin-induced myotoxicity cases), rs59502379 (odds ratio [OR] = 2.85, 95% confidence interval [CI] 1.08-7.52), but not rs77271279 (OR = 1.75, 95% CI 0.62-4.73) was associated with myotoxicity. Sensitivity analyses in participants with >5% AFR-like genetic similarity corroborated these findings. For white participants, rs77271279 and rs59502379 were rare precluding subsequent analyses. Our findings highlight the clinical relevance for understudied SLCO1B1 variants on pharmacogenetic testing panels with a potential immediate impact on reducing the risk of severe statin-induced myotoxicity primarily in Black patients, a group historically excluded from genomic research. Future studies require larger statin user study populations with less heterogeneity by statin type.

Pharmacogenomic insights into atorvastatin and rosuvastatin adverse effects: a prospective observational study in the UAE's multiethnic population

BACKGROUND

Statins are essential for managing cardiovascular disease (CVD), but adverse effects often lead to treatment discontinuation and non-adherence, underscoring the need for personalized approaches. This study aimed to evaluate the influence of pharmacogenomic (PGx) variants and demographic factors on statin-associated adverse effects in a multiethnic cohort from the United Arab Emirates (UAE).

METHODS

This sub-analysis of the EmHeart Study included 675 patients using rosuvastatin or atorvastatin. Patients were genotyped for SLCO1B1 and ABCG2 actionable variants using real-time PCR. Data on demographics, comorbidities, and statin use were extracted from electronic health records. Adverse events, including statin-associated muscle symptoms (SAMS) and liver enzyme elevation, were tracked over 12 months. Associations were analyzed using chi-square tests and logistic regression.

RESULTS

Rosuvastatin users carrying the ABCG2 rs2231142 variant had a threefold increased risk of liver enzyme elevation, particularly among East Asian patients (P < 0.005). Atorvastatin users with the SLCO1B1 rs4149056 variant exhibited a twofold increased risk of SAMS, with higher rates observed in females and Arabs (P < 0.05). The combination of rosuvastatin with ezetimibe further exacerbated risks of SAMS and liver enzyme elevation.

CONCLUSION

This study highlights the importance of genetic testing and demographic factors, such as ethnicity and gender, in tailoring statin therapy to minimize adverse effects. Despite extensive research on PGx-guided statin prescribing, clinical implementation remains limited. Integrating PGx testing into routine practice and enhancing physician awareness of genetic and demographic risk factors can improve the safety, efficacy, and adherence of lipid-lowering therapies in diverse populations.

Evaluation of pharmacogenomic testing to identify cytochrome P450 and SLCO1B1 enzymes and adverse drug events: A non-experimental observational research

A laboratory-initiated preemptive and reactive cytochrome P450 and SLCO1B1 PGx testing protocol was evaluated in a private toxicology laboratory with the intent of identifying enzyme frequencies and associated adverse drug events. This study involved non-experimental observational research. During the retrospective medical chart review, patient demographics, statements of medical necessity, and PGx testing data were collected. Frequencies and percentages were calculated for the collected data, and statistical analysis was performed using Intellectus online software. A total of 192 PGx patient records from September 2019 to October 2021 were retrospectively reviewed. For patient demographics, men (n = 118; (61%)) were the majority gender identified among the patient population and Caucasians (n = 112; (58%)) followed by African Americans (n = 37; (19%)) were the most identified ancestry. The mean age of the patients was 69 (±9) years. CYP1A2 hyperinducers, followed by CYP3A5 poor metabolizers and CYP2B6 intermediate metabolizers, are the most encountered cytochrome P450 and SLCO1B1 enzymes. Regarding drug-gene interactions, 41 patients had 1 interaction, 29 had 2, and 31 had 3 or more interactions. For drug-drug interactions, 35 patients had 1 interaction, 15 had 2, and 30 had 3 or more interactions. Overall, 123 patients showed a minor or greater impact on drug-drug or drug-gene interactions. Overall, our study identified cytochrome P450 and SCLCO1B1 enzyme frequencies and patients experiencing actionable adverse drug events. By raising awareness of PGx test results through individualized clinician training, education, and interventions, these adverse events can be promptly identified and resolved.

Striving Towards Equity in Cardiovascular Genomics Research

PURPOSE OF REVIEW

Our review emphasizes recent advancements and persisting gaps in cardiovascular genomics, particularly highlighting how emerging studies involving underrepresented populations have uncovered new genetic variants associated with cardiovascular diseases.

RECENT FINDINGS

Initiatives like the H3Africa project, the Million Veterans Program, and the All of Us Research Program are working to address this gap by focusing on underrepresented groups. Additionally, emerging research is centering on the interplay between genetic factors and socio-environmental determinants of health, which disproportionately impact marginalized communities. As cardiovascular genomics research grows, increasing the inclusion of underrepresented populations is essential for gaining a more comprehensive understanding of genetic variability. This will lead to more accurate and clinically meaningful strategies for preventing and treating cardiovascular diseases across all ancestral backgrounds and diverse populations.

Evaluation of statin-induced muscle and liver adverse drug reactions in the Chinese population: a retrospective analysis of clinical trial data from 1992 to 2023

OBJECTIVES

This study addressed the gaps in the disclosure of statin-associated adverse drug reactions (ADRs) in China's official database and the inadequacy of cases reported relative to the population size in public ADR databases.

METHODS

To address these limitations, we conducted a retrospective trial-based analysis using data from Chinese journals to comprehensively assess statin-associated ADRs from 1992 to 2023, focusing on liver (2895 studies, n = 163 810) and muscle (2888 studies, n = 161 714) related outcomes.

RESULTS

For large sample size clinical trial analysis (n≥100), our analysis encompassed data from 31 763 participants for muscle-related ADRs (incidence rate: 0.004-0.006, common effect model; 0.002-0.006, random effects model) and 31 281 participants for liver-related ADRs (incidence rate: 0.004-0.006, common effect model; 0.003-0.006, random effects model), covering various statins, including atorvastatin, simvastatin, rosuvastatin, fluvastatin, pitavastatin, pravastatin and lovastatin. Notably, muscle-related ADRs, particularly rhabdomyolysis, were most prevalent with fluvastatin, lovastatin and pravastatin, showing rates of 0.90%, 0.74% and 0.53%, respectively. Pitavastatin and atorvastatin were frequently associated with liver-related ADRs such as abnormal liver function and elevated enzymes, with rates of 5.36% and 1.819%, respectively.

CONCLUSIONS

This study underscores significant variations in ADR incidence among different statins in the Chinese population, providing critical insights for healthcare professionals and policymakers to enhance patient safety and optimise clinical decisions regarding statin therapy.

Effect of Staggered vs. Simultaneous Co-Administration of Bempedoic Acid on Pharmacokinetics of Pravastatin: Randomized, Cross-Over Clinical Trial in Healthy Volunteers

Background/Objectives: Bempedoic acid (BA) is a novel cholesterol-lowering agent with proven positive effects on cardiovascular endpoints. Because it is an inhibitor of the hepatic transporters OATP1B1 and OATP1B3, two uptake transporters regulating the intrahepatic availability of statins, it increases the systemic exposure of co-administered statins. This interaction could raise the risk of myopathy. We hypothesized that the drug interaction between BA and statins could be mitigated by staggered administration. Methods: This was a single-centre, open-label, randomized, two-arm, cross-over, phase I drug interaction trial in healthy volunteers (EudraCT-No: 2022-001096-13). The primary objective was to evaluate the OATP1B1 inhibitory effect of BA on exposure to pravastatin after simultaneous administration versus different schedules of staggered administration. A secondary objective was to evaluate the impact of SLCO1B1 genotypes (*1, *5, *15, *37) on pravastatin exposure. Pravastatin was administered in single oral doses of 40 mg at six visits. After a baseline visit with pravastatin alone, BA was dosed to steady state at the approved oral dose of 180 mg. Outcome measures were the area under the plasma concentration-time curve, extrapolated to infinity (AUC∞) and Cmax of pravastatin, 3α-hydroxy-pravastatin (pravastatin 3-iso), and pravastatin lactone, and their geometric mean ratios (GMRs) of different schedules of administration. Log-transformed AUC∞ and Cmax were compared with one-way ANOVA with a 90% confidence interval (CI). Results: Fourteen participants completed all visits. At BA steady state, the GMRs of pravastatin AUC∞ and Cmax were 1.80 (90% CI 1.31-2.46) and 1.95 (90% CI 1.40-2.72), respectively, compared to baseline. There was no significant difference in pravastatin exposure between simultaneous vs. staggered administration. There was no statistically significant difference in pravastatin 3-iso or pravastatin lactone between different administration modes. For the AUC∞ of pravastatin and pravastatin 3-iso, haplotype was a significant source of variation (63% and 20%, respectively), while the type of administration (simultaneous vs. staggered) had no significant impact. Conclusions: The increase in pravastatin exposure with concomitant intake of BA was larger than expected. There was no significant difference between simultaneous vs. staggered administration of pravastatin and BA, possibly due to a population that was heterogenous in SLCO1B1 haplotypes.

Value of Pharmacogenetic Testing Assessed with Real-World Drug Utilization and Genotype Data

Implementation of pharmacogenetic testing in clinical care has been slow and with few exceptions is hindered by the lack of real-world evidence on how to best target testing. In this retrospective register-based study, we analyzed a nationwide cohort of 1,425,000 patients discharged from internal medicine or surgical wards and a cohort of 2,178 university hospital patients for purchases and prescriptions of pharmacogenetically actionable drugs. Pharmacogenetic variants were obtained from whole genome genotype data for a subset (n = 930) of the university hospital patients. We investigated factors associated with receiving pharmacogenetically actionable drugs and developed a literature-based cost-benefit model for pre-emptive pharmacogenetic panel testing. In a 2-year follow-up, 60.4% of the patients in the nationwide cohort purchased at least one pharmacogenetically actionable drug, most commonly ibuprofen (25.0%) and codeine (19.4%). Of the genotyped subset, 98.8% carried at least one actionable pharmacogenetic genotype and 23.3% had at least one actionable gene-drug pair. Patients suffering from musculoskeletal or cardiovascular diseases were more prone to receive pharmacogenetically actionable drugs during inpatient episode. The cost-benefit model included frequently dispensed drugs in the university hospital cohort, comprising ondansetron (19.4%), simvastatin (7.4%), clopidogrel (5.0%), warfarin (5.1%), (es)citalopram (5.3%), and azathioprine (0.5%). For untargeted pre-emptive pharmacogenetic testing of all university hospital patients, the model indicated saving €17.49 in direct healthcare system costs per patient in 2 years without accounting for the cost of the test itself. Therefore, it might be reasonable to target pre-emptive pharmacogenetic testing to patient groups most likely to receive pharmacogenetically actionable drugs.

Effect of Genetic Variants on Rosuvastatin Pharmacokinetics in Healthy Volunteers: Involvement of ABCG2, SLCO1B1 and NAT2

Statins are the primary drugs used to prevent cardiovascular disease by inhibiting the HMG-CoA reductase, an enzyme crucial for the synthesis of LDL cholesterol in the liver. A significant number of patients experience adverse drug reactions (ADRs), particularly musculoskeletal problems, which can affect adherence to treatment. Recent clinical guidelines, such as those from the Clinical Pharmacogenetics Implementation Consortium (CPIC) in 2022, recommend adjusting rosuvastatin doses based on genetic variations in the ABCG2 and SLCO1B1 genes to minimize ADRs and improve treatment efficacy. Despite these adjustments, some patients still experience ADRs. So, we performed a candidate gene study to better understand the pharmacogenetics of rosuvastatin. This study included 119 healthy volunteers who participated in three bioequivalence trials of rosuvastatin alone or in combination with ezetimibe at the Clinical Trials Unit of the Hospital Universitario de La Princesa (UECHUP). Participants were genotyped using a custom OpenArray from ThermoFisher that assessed 124 variants in 38 genes associated with drug metabolism and transport. No significant differences were observed according to sex or biogeographic origin. A significant increase in t1/2 (pmultivariate(pmv) = 0.013) was observed in the rosuvastatin plus ezetimibe trial compared with the rosuvastatin alone trials. Genetic analysis showed that decreased (DF) and poor function (PF) volunteers for the ABCG2 transporter had higher AUC∞/DW (adjusted dose/weight), AUC72h/DW and Cmax/DW compared to normal function (NF) volunteers (pmv< 0.001). DF and PF volunteers for SLCO1B1 showed an increase in AUC72h/DW (pmv = 0.020) compared to increased (IF) and NF individuals. Results for ABCG2 and SLCO1B1 were consistent with the existing literature. In addition, AUC∞/DW, AUC72h/DW and Cmax/DW were increased in intermediate (IA) and poor (PA) NAT2 acetylators (pmv = 0.001, pmv< 0.001, pmv< 0.001, respectively) compared to rapid acetylators (RA), which could be associated through a secondary pathway that was previously unknown.

An Investigational Study on the Role of CYP2D6, CYP3A4 and UGTs Genetic Variation on Fesoterodine Pharmacokinetics in Young Healthy Volunteers

Introduction: Fesoterodine is one of the most widely used antimuscarinic drugs to treat an overactive bladder. Fesoterodine is extensively hydrolyzed by esterases to 5-hydroxymethyl tolterodine (5-HMT), the major active metabolite. CYP2D6 and CYP3A4 mainly metabolize 5-HMT and are, therefore, the primary pharmacogenetic candidate biomarkers. Materials and Methods: This is a candidate gene study designed to investigate the effects of 120 polymorphisms in 33 genes (including the CYP, COMT, UGT, NAT2, and CES enzymes, ABC and SLC transporters, and 5-HT receptors) on fesoterodine pharmacokinetics and their safety in 39 healthy volunteers from three bioequivalence trials. Results: An association between 5-HMT exposure (dose/weight corrected area under the curve (AUC/DW) and dose/weight corrected maximum plasma concentration (Cmax/DW)), elimination (terminal half-life (T1/2) and the total drug clearance adjusted for bioavailability (Cl/F)), and CYP2D6 activity was observed. Poor/intermediate metabolizers (PMs/IMs) had higher 5-HMT AUC/DW (1.5-fold) and Cmax/DW (1.4-fold) values than the normal metabolizers (NMs); in addition, the normal metabolizers (NMs) had higher 5-HMT AUC/DW (1.7-fold) and Cmax/DW (1.3-fold) values than the ultrarapid metabolizers (UMs). Lower 5-HMT exposure and higher T1/2 were observed for the CYP3A4 IMs compared to the NMs, contrary to our expectations. Conclusions: CYP2D6 might have a more important role than CYP3A4 in fesoterodine pharmacokinetics, and its phenotype might be a better predictor of variation in its pharmacokinetics. An association was observed between different genetic variants of different genes of the UGT family and AUC, Cmax, and CL/F of 5-HMT, which should be confirmed in other studies.

Allelic frequencies of polymorphism c.521T>C (rs4149056) favor preemptive SLCO1B1 genotyping in Armenia

OBJECTIVES

Statins represent an important pharmacological factor for the prevention of cardiovascular diseases but may also cause severe cases of myotoxicity. Numerous studies have described the association of the SLCO1B1 gene variant c.521C with statin-induced myopathy across different populations. This study aimed at evaluating the usefulness of preemptive SLCO1B1 genotyping in Armenia.

METHODS

A total of 202 Armenian patients referred to the Center of Medical Genetics and Primary Health Care in Yerevan for upper respiratory tract infection between January and May 2022 were included in this study. Genotyping for SLCO1B1 c.521T>C (rs4149056) was performed using a commercially available real-time PCR assay (RealFast™).

RESULTS

In total, 3/202 (1.5 %) samples were C/C homozygotes and 52/202 (25.7 %) were T/C heterozygotes, associated with a high and increased risk for statin-induced myopathy, respectively. The SLCO1B1 c.521C allelic frequency was 14.4 %.

CONCLUSIONS

The observed allele frequency of 14.4 % for the c.521C variant is slightly lower than frequencies reported from Europe, but relatively high compared to Asian populations, suggesting that preemptive SLCO1B1 genotyping could be a useful approach for the reduction of statin-induced adverse effects in Armenia.

From Drug Discovery to Drug Approval: A Comprehensive Review of the Pharmacogenomics Status Quo with a Special Focus on Egypt

Pharmacogenomics (PGx) is the hope for the full optimization of drug therapy while minimizing the accompanying adverse drug events that cost billions of dollars annually. Since years before the century, it has been known that inter-individual variations contribute to differences in specific drug responses. It is the bridge to what is well-known today as "personalized medicine". Addressing the drug's pharmacokinetics and pharmacodynamics is one of the features of this science, owing to patient characteristics that vary on so many occasions. Mainly in the liver parenchymal cells, intricate interactions between the drug molecules and enzymes family of so-called "Cytochrome P450" occur which hugely affects how the body will react to the drug in terms of metabolism, efficacy, and safety. Single nucleotide polymorphisms, once validated for a transparent and credible clinical utility, can be used to guide and ensure the succession of the pharmacotherapy plan. Novel tools of pharmacoeconomics science are utilized extensively to assess cost-effective pharmacogenes preceding the translation to the bedside. Drug development and discovery incorporate a drug-gene perspective and save more resources. Regulations and laws shaping the clinical PGx practice can be misconceived; however, these pre-/post approval processes ensure the product's safety and efficacy. National and international regulatory agencies seek guidance on maintaining conduct in PGx practice. In this patient-centric era, social and legal considerations manifest in a way that makes them unavoidable, involving patients and other stakeholders in a deliberate journey toward utmost patient well-being. In this comprehensive review, we contemporarily addressed the scientific leaps in PGx, along with various challenges that face the proper implementation of personalized medicine in Egypt. These informative insights were drawn to serve what the Egyptian population, in particular, would benefit from in terms of knowledge and know-how while maintaining the latest global trends. Moreover, this review is the first to discuss various modalities and challenges faced in Egypt regarding PGx, which we believe could be used as a pilot piece of literature for future studies locally, regionally, and internationally.

QPGx-CARES: Qatar pharmacogenetics clinical applications and research enhancement strategies

Pharmacogenetic (PGx)-informed medication prescription is a cutting-edge genomic application in contemporary medicine, offering the potential to overcome the conventional "trial-and-error" approach in drug prescription. The ability to use an individual's genetic profile to predict drug responses allows for personalized drug and dosage selection, thereby enhancing the safety and efficacy of treatments. However, despite significant scientific and clinical advancements in PGx, its integration into routine healthcare practices remains limited. To address this gap, the Qatar Genome Program (QGP) has embarked on an ambitious initiative known as QPGx-CARES (Qatar Pharmacogenetics Clinical Applications and Research Enhancement Strategies), which aims to set a roadmap for optimizing PGx research and clinical implementation on a national scale. The goal of QPGx-CARES initiative is to integrate PGx testing into clinical settings with the aim of improving patient health outcomes. In 2022, QGP initiated several implementation projects in various clinical settings. These projects aimed to evaluate the clinical utility of PGx testing, gather valuable insights into the effective dissemination of PGx data to healthcare professionals and patients, and identify the gaps and the challenges for wider adoption. QPGx-CARES strategy aimed to integrate evidence-based PGx findings into clinical practice, focusing on implementing PGx testing for cardiovascular medications, supported by robust scientific evidence. The current initiative sets a precedent for the nationwide implementation of precision medicine across diverse clinical domains.

Major Genetic Drivers of Statin Treatment Response in African Populations and Pharmacogenetics of Dyslipidemia Through a One Health Lens

A One Health lens is increasingly significant to address the intertwined challenges in planetary health concerned with the health of humans, nonhuman animals, plants, and ecosystems. A One Health approach can benefit the public health systems in Africa that are overburdened by noncommunicable, infectious, and environmental diseases. Notably, the COVID-19 pandemic revealed the previously overlooked two-fold importance of pharmacogenetics (PGx), for individually tailored treatment of noncommunicable diseases and environmental pathogens. For example, dyslipidemia, a common cardiometabolic risk factor, has been identified as an independent COVID-19 severity risk factor. Observational data suggest that patients with COVID-19 infection receiving lipid-lowering therapy may have better outcomes. However, among African patients, the response to these drugs varies from patient to patient, pointing to the possible contribution of genetic variation in important pharmacogenes. The PGx of lipid-lowering therapies may underlie differences in treatment responses observed among dyslipidemia patients as well as patients comorbid with COVID-19 and dyslipidemia. Genetic variations in APOE, ABCB1, CETP, CYP2C9, CYP3A4, CYP3A5, HMGCR, LDLR, NPC1L1, and SLCO1B1 genes affect the pharmacogenomics of statins, and they have individually been linked to differential responses to dyslipidemia and COVID-19 treatment. African populations are underrepresented in PGx research. This leads to poor accounting of additional diverse genetic variants that could be important in understanding interindividual and between-population variations in therapeutic responses to dyslipidemia and COVID-19. This expert review examines and synthesizes the salient and priority PGx variations, as seen through a One Health lens in Africa, to improve and inform personalized medicine in both dyslipidemia and COVID-19.

Use of drugs with pharmacogenomics (PGx)-based dosing guidelines in a Danish cohort of persons with chronic kidney disease, both on dialysis and not on dialysis: Perspectives for prescribing optimization

AIM

The objective of this registry study is to assess the utilization of pharmacogenomic (PGx) drugs among patients with chronic kidney disease (CKD).

METHODS

This study was a retrospective study of patients affiliated with the Department of Nephrology, Aalborg University Hospital, Denmark in 2021. Patients diagnosed with CKD were divided into CKD without dialysis and CKD with dialysis. PGx prescription drugs were retrieved from the Patient Administration System. Actionable dosing guidelines (AG) for specific drug-gene pairs for CYP2D6, CYP2C9, CYP2C19 and SLCO1B1 were retrieved from the PharmGKB homepage.

RESULTS

Out of 1241 individuals, 25.5% were on dialysis. The median number of medications for each patient was 9 within the non-dialysis group and 16 within the dialysis group. Thirty-one distinct PGx drugs were prescribed. Altogether, 76.0% (943 individuals) were prescribed at least one PGx drug and the prevalence of prescriptions of PGx drugs was higher in the dialysis group compared to the non-dialysis group. The most frequently prescribed drugs with AG were metoprolol, pantoprazole, atorvastatin, simvastatin and warfarin.

CONCLUSION

This study demonstrated that a substantial proportion of patients with CKD are exposed to drugs or drug combinations for which there exists AG related to PGx of CYP2D6, CYP2C19, CYP2C9 and SLCO1B1.

Large-scale next generation sequencing based analysis of SLCO1B1 pharmacogenetics variants in the Saudi population

BACKGROUND

SLCO1B1 plays an important role in mediating hepatic clearance of many different drugs including statins, angiotensin-converting enzyme inhibitors, chemotherapeutic agents and antibiotics. Several variants in SLCO1B1 have been shown to have a clinically significant impact, in relation to efficacy of these medications. This study provides a comprehensive overview of SLCO1B1 variation in Saudi individuals, one of the largest Arab populations in the Middle East.

METHODS

The dataset of 11,889 (9,961 exomes and 1,928 pharmacogenetic gene panel) Saudi nationals, was used to determine the presence and frequencies of SLCO1B1 variants, as described by the Clinical Pharmacogenetic Implementation Consortium (CPIC).

RESULTS

We identified 141 previously described SNPs, of which rs2306283 (50%) and rs4149056 (28%), were the most common. In addition, we observed six alleles [*15 (24.7%) followed by *20 (8.04%), *14 (5.86%), *5 (3.84%), *31 (0.21%) and *9 (0.03%)] predicted to be clinically actionable. Allele diplotype to phenotype conversion revealed 41 OATP1B1 diplotypes. We estimated the burden of rare, and novel predicted deleterious variants, resulting from 17 such alterations.

CONCLUSIONS

The data we present, from one of the largest Arab cohorts studied to date, provides the most comprehensive overview of SLCO1B1 variants, and the subsequent OATP1B1 activity of this ethnic group, which thus far remains relatively underrepresented in available international genomic databases. We believe that the presented data provides a basis for further clinical investigations and the application of personalized statin drug therapy guidance in Arabs.

Impact of CYP2D6 and CYP2B6 phenotypes on the response to tramadol in patients with acute post-surgical pain

Tramadol is an important minor opioid prescribed for pain management. In this study, we analyzed the well-known impact of CYP2D6 genetic variation and 60 additional variants in eight candidate genes (i.e., ABCG2, SLCO1B1, CYP2D6, CYP2B6, CYP2C19, CYP2C9, CYP3A5, and CYP3A4) on tramadol efficacy and safety. Some 108 patients with pain after surgery admitted to a post-anesthesia care unit (PACU) and prescribed tramadol were recruited. They were genotyped, and tramadol M1/M2 metabolite concentrations were determined by a newly validated HPLC-MS/MS method. CYP2D6 intermediate (IM) and poor (PM) metabolizers showed lower M1 concentrations adjusted for dose/weight at 30 and 120 min compared to ultrarapid (UM) and normal (NM) metabolizers (univariate p < 0.001 and 0.020, multivariate p < 0.001 and 0.001, unstandardized β coefficients = 0.386 and 0.346, R2  = 0.146 and 0.120, respectively). CYP2B6 PMs (n = 10) were significantly related to a higher reduction in pain 30 min after tramadol intake (univariate p = 0.038, multivariate p = 0.016, unstandardized β coefficient = 0.224, R2  = 0.178), to lower PACU admission time (p = 0.007), and to lower incidence of adverse drug reactions (p = 0.038) compared to the other phenotypes. CYP3A4 IMs and PMs showed a higher prevalence of drowsiness and dizziness (p = 0.028 and 0.005, respectively). Our results suggest that the interaction of CYP2B6 and CYP2D6 phenotypes may be clinically relevant, pending validation of these results in large, independent cohorts. Additional research is required to clarify the impact of CYP3A4 genetic variation on tramadol response.

A Digital Health Perspective on Medication Use and Polypharmacy Management for Improving Healthcare Outcomes in Geriatric Patients

The high prevalence of multiple comorbidities poses unique medication-related challenges for geriatric patients. Polypharmacy is a particular concern since taking several medications simultaneously increases the likelihood of adverse drug events and the risk of drug interactions while decreasing patient adherence. These factors are associated with suboptimal health outcomes and a heightened burden on the healthcare system (insurance claims) and the patient (out-of-pocket expenses). These challenges can significantly affect the quality of life of geriatric patients. This chapter critically examines the impact of medication use and polypharmacy on the quality of life of older patients. In addition, the authors discuss how artificial intelligence-based digital tools and precision medicine can address these issues by streamlining medical decision-making, improving the patient experience, and allowing remote monitoring. Finally, they interpret the findings from the lens of ethical considerations associated with the adoption and implementation of digital applications and gadgets.

Influencia de la farmacogenética en la diversidad de respuesta a las estatinas asociada a las reacciones adversas

Introducción

Las estatinas son unos de los medicamentos más prescritos en los países desarrollados por ser el tratamiento de elección para reducir los niveles de colesterol ayudando así a prevenir la enfermedad cardiovascular. Sin embargo, un gran número de pacientes sufre reacciones adversas, en especial miotoxicidad. Entre los factores que influyen en la diversidad de respuesta, la farmacogenética puede jugar un papel relevante especialmente en la prevención de los efectos adversos asociados a estos medicamentos.

Contenido

Revisión de los conocimientos actuales sobre la influencia de la farmacogenética en la aparición y prevención de las reacciones adversas asociadas a estatinas, así como del beneficio clínico del test farmacogenético anticipado.

Resumen

Variaciones genéticas en SLCO1B1 (rs4149056) para todas las estatinas; en ABCG2 (rs2231142) para rosuvastatina; o en CYP2C9 (rs1799853 y rs1057910) para fluvastatina están asociadas a un incremento de las reacciones adversas de tipo muscular y a una baja adherencia al tratamiento. Además, diversos fármacos inhibidores de estos transportadores y enzimas de biotransformación incrementan la exposición sistémica de las estatinas favoreciendo la aparición de las reacciones adversas.

Perspectiva

La implementación clínica del análisis anticipado de este panel de farmacogenética evitaría en gran parte la aparición de reacciones adversas. Además, la estandarización en la identificación de los efectos adversos, en la metodología e interpretación del genotipo, permitirá obtener resultados más concluyentes sobre la asociación entre las variantes genéticas del SLCO1B1, ABCG y CYP2C9 y la aparición de reacciones adversas y establecer recomendaciones para alcanzar tratamientos más personalizados para cada estatina.

Influence of pharmacogenetics on the diversity of response to statins associated with adverse drug reactions

Background

Statins are one of the most prescribed medications in developed countries as the treatment of choice for reducing cholesterol and preventing cardiovascular diseases. However, a large proportion of patients experience adverse drug reactions, especially myotoxicity. Among the factors that influence the diversity of response, pharmacogenetics emerges as a relevant factor of influence in inter-individual differences in response to statins and can be useful in the prevention of adverse drug effects.

Content

A systematic review was performed of current knowledge of the influence of pharmacogenetics on the occurrence and prevention of statin-associated adverse reactions and clinical benefits of preemptive pharmacogenetics testing.

Summary

Genetic variants SLCO1B1 (rs4149056) for all statins; ABCG2 (rs2231142) for rosuvastatin; or CYP2C9 (rs1799853 and rs1057910) for fluvastatin are associated with an increase in muscle-related adverse effects and poor treatment adherence. Besides, various inhibitors of these transporters and biotransformation enzymes increase the systemic exposure of statins, thereby favoring the occurrence of adverse drug reactions.

Outlook

The clinical preemptive testing of this pharmacogenetic panel would largely prevent the incidence of adverse drug reactions. Standardized methods should be used for the identification of adverse effects and the performance and interpretation of genotyping test results. Standardization would allow to obtain more conclusive results about the association between SLCO1B1, ABCG and CYP2C9 variants and the occurrence of adverse drug reactions. As a result, more personalized recommendations could be established for each statin.

Estimating the efficacy of pharmacogenomics over a lifetime

It is well known that common variants in specific genes influence drug metabolism and response, but it is currently unknown what fraction of patients are given prescriptions over a lifetime that could be contraindicated by their pharmacogenomic profiles. To determine the clinical utility of pharmacogenomics over a lifetime in a general patient population, we sequenced the genomes of 300 deceased Marshfield Clinic patients linked to lifelong medical records. Genetic variants in 33 pharmacogenes were evaluated for their lifetime impact on drug prescribing using extensive electronic health records. Results show that 93% of the 300 deceased patients carried clinically relevant variants. Nearly 80% were prescribed approximately three medications on average that may have been impacted by these variants. Longitudinal data suggested that the optimal age for pharmacogenomic testing was prior to age 50, but the optimal age is greatly influenced by the stability of the population in the healthcare system. This study emphasizes the broad clinical impact of pharmacogenomic testing over a lifetime and demonstrates the potential application of genomic medicine in a general patient population for the advancement of precision medicine.

A review on the efficacy and safety of lipid-lowering drugs in neurodegenerative disease

There is a train of thought that lipid therapies may delay or limit the impact of neuronal loss and poor patient outcomes of neurodegenerative diseases (NDDs). A variety of medicines including lipid lowering modifiers (LLMs) are prescribed in NDDs. This paper summarizes the findings of clinical and observational trials including systematic reviews and meta-analyses relating to LLM use in NDDs published in the last 15 years thus providing an up-to-date evidence pool. Three databases were searched PubMed, CINAHL, and Web of Science using key terms relating to the review question. The findings confirm the benefit of LLMs in hyperlipidemic patients with or without cardiovascular risk factors due to their pleotropic effects. In NDDs LLMs are proposed to delay disease onset and slow the rate of progression. Clinical observations show that LLMs protect neurons from α-synuclein, tau, and Aβ toxicity, activation of inflammatory processes, and ultimately oxidative injury. Moreover, current meta-analyses and clinical trials indicated low rates of adverse events with LLMs when used as monotherapy. LLMs appear to have favorable safety and tolerability profiles with few patients stopping treatment due to severe adverse effects. Our collated evidence thus concludes that LLMs have a role in NDDs but further work is needed to understand the exact mechanism of action and reach more robust conclusions on where and when it is appropriate to use LLMs in NDDs in the clinic.

Impact of Sex and Genetic Variation in Relevant Pharmacogenes on the Pharmacokinetics and Safety of Valsartan, Olmesartan and Hydrochlorothiazide

Drug combination therapy is the most common pharmacological strategy for hypertension management. No pharmacogenetic biomarkers for guiding hypertension pharmacotherapy are available to date. The study population were 64 volunteers from seven bioequivalence trials investigating formulations with valsartan, olmesartan and/or hydrochlorothiazide. Every volunteer was genotyped for 10 genetic variants in different transporters' genes. Additionally, valsartan-treated volunteers were genotyped for 29 genetic variants in genes encoding for different metabolizing enzymes. Variability in pharmacokinetic parameters such as maximum concentration (Cmax) and time to reach it (tmax), the incidence of adverse drug reactions (ADRs) and blood pressure measurements were analyzed as a function of pharmacogenetic and demographic parameters. Individuals with the ABCB1 rs1045642 T/T genotype were associated with a higher valsartan tmax compared to those with T/G and G/G genotypes (p < 0.001, β = 0.821, R2 = 0.459) and with a tendency toward a higher postural dizziness incidence (11.8% vs. 0%, p = 0.070). A higher hydrochlorothiazide dose/weight (DW)-corrected area under the curve (AUC∞/DW) was observed in SLC22A1 rs34059508 G/A volunteers compared to G/G volunteers (p = 0.050, β = 1047.35, R2 = 0.051), and a tendency toward a higher postural dizziness incidence (50% vs. 1.6%, p = 0.063). Sex impacted valsartan and hydrochlorothiazide pharmacokinetics, showing a lower exposure in women, whereas no significant differences were found for olmesartan pharmacokinetics.

Implementation of Pharmacogenetics in First-Line Care: Evaluation of Its Use by General Practitioners

Pharmacogenetics (PGx) can explain/predict drug therapy outcomes. There is, however, unclarity about the use and usefulness of PGx in primary care. In this study, we investigated PGx tests ordered by general practitioners (GPs) in 2021 at Dept. Clinical Chemistry, Erasmus MC, and analyzed the gene tests ordered, drugs/drug groups, reasons for testing and single-gene versus panel testing. Additionally, a survey was sent to 90 GPs asking about their experiences and barriers to implementing PGx. In total, 1206 patients and 6300 PGx tests were requested by GPs. CYP2C19 was requested most frequently (17%), and clopidogrel was the most commonly indicated drug (23%). Regarding drug groups, antidepressants (51%) were the main driver for requesting PGx, followed by antihypertensives (26%). Side effects (79%) and non-response (27%) were the main indicators. Panel testing was preferred over single-gene testing. The survey revealed knowledge on when and how to use PGx as one of the main barriers. In conclusion, PGx is currently used by GPs in clinical practice in the Netherlands. Side effects are the main reason for testing, which mostly involves antidepressants. Lack of knowledge is indicated as a major barrier, indicating the need for more education on PGx for GPs.

Real-world pharmacogenetics of statin intolerance: effects of SLCO1B1, ABCG2 , and CYP2C9 variants

OBJECTIVE

The association of SLCO1B1 c.521T>C with simvastatin-induced muscle toxicity is well characterized. However, different statins are subject to metabolism and transport also by other proteins exhibiting clinically meaningful genetic variation. Our aim was to investigate associations of SLCO1B1 c.521T>C with intolerance to atorvastatin, fluvastatin, pravastatin, rosuvastatin, or simvastatin, those of ABCG2 c.421C>A with intolerance to atorvastatin, fluvastatin, or rosuvastatin, and that of CYP2C9*2 and *3 alleles with intolerance to fluvastatin.

METHODS

We studied the associations of these variants with statin intolerance in 2042 patients initiating statin therapy by combining genetic data from samples from the Helsinki Biobank to clinical chemistry and statin purchase data.

RESULTS

We confirmed the association of SLCO1B1 c.521C/C genotype with simvastatin intolerance both by using phenotype of switching initial statin to another as a marker of statin intolerance [hazard ratio (HR) 1.88, 95% confidence interval (CI) 1.08-3.25, P  = 0.025] and statin switching along with creatine kinase measurement (HR 5.44, 95% CI 1.49-19.9, P  = 0.011). No significant association was observed with atorvastatin and rosuvastatin. The sample sizes for fluvastatin and pravastatin were relatively small, but SLCO1B1 c.521T>C carriers had an increased risk of pravastatin intolerance defined by statin switching when compared to homozygous reference T/T genotype (HR 2.11, 95% CI 1.01-4.39, P  = 0.047).

CONCLUSION

The current results can inform pharmacogenetic statin prescribing guidelines and show feasibility for the methodology to be used in larger future studies.

An Introductory Tutorial on Cardiovascular Pharmacogenetics for Healthcare Providers

Pharmacogenetics can improve clinical outcomes by reducing adverse drug effects and enhancing therapeutic efficacy for commonly used drugs that treat a wide range of cardiovascular diseases. One of the major barriers to the clinical implementation of cardiovascular pharmacogenetics is limited education on this field for current healthcare providers and students. The abundance of pharmacogenetic literature underscores its promise, but it can also be challenging to learn such a wealth of information. Moreover, current clinical recommendations for cardiovascular pharmacogenetics can be confusing because they are outdated, incomplete, or inconsistent. A myriad of misconceptions about the promise and feasibility of cardiovascular pharmacogenetics among healthcare providers also has halted clinical implementation. Therefore, the main goal of this tutorial is to provide introductory education on the use of cardiovascular pharmacogenetics in clinical practice. The target audience is any healthcare provider (or student) with patients that use or have indications for cardiovascular drugs. This tutorial is organized into the following 6 steps: (1) understand basic concepts in pharmacogenetics; (2) gain foundational knowledge of cardiovascular pharmacogenetics; (3) learn the different organizations that release cardiovascular pharmacogenetic guidelines and recommendations; (4) know the current cardiovascular drugs/drug classes to focus on clinically and the supporting evidence; (5) discuss an example patient case of cardiovascular pharmacogenetics; and (6) develop an appreciation for emerging areas in cardiovascular pharmacogenetics. Ultimately, improved education among healthcare providers on cardiovascular pharmacogenetics will lead to a greater understanding for its potential in improving outcomes for a leading cause of morbidity and mortality.

Towards Evidence-Based Implementation of Pharmacogenomics in Southern Africa: Comorbidities and Polypharmacy Profiles across Diseases

Pharmacogenomics may improve patient care by guiding drug selection and dosing; however, this requires prior knowledge of the pharmacogenomics of drugs commonly used in a specific setting. The aim of this study was to identify a preliminary set of pharmacogenetic variants important in Southern Africa. We describe comorbidities in 3997 patients from Malawi, South Africa, and Zimbabwe. These patient cohorts were included in pharmacogenomic studies of anticoagulation, dyslipidemia, hypertension, HIV and breast cancer. The 20 topmost prescribed drugs in this population were identified. Using the literature, a list of pharmacogenes vital in the response to the top 20 drugs was constructed leading to drug-gene pairs potentially informative in translation of pharmacogenomics. The most reported morbidity was hypertension (58.4%), making antihypertensives the most prescribed drugs, particularly amlodipine. Dyslipidemia occurred in 31.5% of the participants, and statins were the most frequently prescribed as cholesterol-lowering drugs. HIV was reported in 20.3% of the study participants, with lamivudine/stavudine/efavirenz being the most prescribed antiretroviral combination. Based on these data, pharmacogenes of immediate interest in Southern African populations include ABCB1, CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP3A4, CYP3A5, SLC22A1, SLCO1B1 and UGT1A1. Variants in these genes are a good starting point for pharmacogenomic translation programs in Southern Africa.

Cardiovascular precision medicine - A pharmacogenomic perspective

Precision medicine envisages the integration of an individual's clinical and biological features obtained from laboratory tests, imaging, high-throughput omics and health records, to drive a personalised approach to diagnosis and treatment with a higher chance of success. As only up to half of patients respond to medication prescribed following the current one-size-fits-all treatment strategy, the need for a more personalised approach is evident. One of the routes to transforming healthcare through precision medicine is pharmacogenomics (PGx). Around 95% of the population is estimated to carry one or more actionable pharmacogenetic variants and over 75% of adults over 50 years old are on a prescription with a known PGx association. Whilst there are compelling examples of pharmacogenomic implementation in clinical practice, the case for cardiovascular PGx is still evolving. In this review, we shall summarise the current status of PGx in cardiovascular diseases and look at the key enablers and barriers to PGx implementation in clinical practice.

Characterization of pharmacogenomic variants in a Brazilian admixed cohort of elderly individuals based on whole-genome sequencing data

Introduction: Research in the field of pharmacogenomics (PGx) aims to identify genetic variants that modulate response to drugs, through alterations in their pharmacokinetics (PK) or pharmacodynamics (PD). The distribution of PGx variants differs considerably among populations, and whole-genome sequencing (WGS) plays a major role as a comprehensive approach to detect both common and rare variants. This study evaluated the frequency of PGx markers in the context of the Brazilian population, using data from a population-based admixed cohort from Sao Paulo, Brazil, which includes variants from WGS of 1,171 unrelated, elderly individuals. Methods: The Stargazer tool was used to call star alleles and structural variants (SVs) from 38 pharmacogenes. Clinically relevant variants were investigated, and the predicted drug response phenotype was analyzed in combination with the medication record to assess individuals potentially at high-risk of gene-drug interaction. Results: In total, 352 unique star alleles or haplotypes were observed, of which 255 and 199 had a frequency < 0.05 and < 0.01, respectively. For star alleles with frequency > 5% (n = 97), decreased, loss-of-function and unknown function accounted for 13.4%, 8.2% and 27.8% of alleles or haplotypes, respectively. Structural variants (SVs) were identified in 35 genes for at least one individual, and occurred with frequencies >5% for CYP2D6, CYP2A6, GSTM1, and UGT2B17. Overall 98.0% of the individuals carried at least one high risk genotype-predicted phenotype in pharmacogenes with PharmGKB level of evidence 1A for drug interaction. The Electronic Health Record (EHR) Priority Result Notation and the cohort medication registry were combined to assess high-risk gene-drug interactions. In general, 42.0% of the cohort used at least one PharmGKB evidence level 1A drug, and 18.9% of individuals who used PharmGKB evidence level 1A drugs had a genotype-predicted phenotype of high-risk gene-drug interaction. Conclusion: This study described the applicability of next-generation sequencing (NGS) techniques for translating PGx variants into clinically relevant phenotypes on a large scale in the Brazilian population and explores the feasibility of systematic adoption of PGx testing in Brazil.

A Comprehensive Analysis of 21 Actionable Pharmacogenes in the Spanish Population: From Genetic Characterisation to Clinical Impact

The implementation of pharmacogenetics (PGx) is a main milestones of precision medicine nowadays in order to achieve safer and more effective therapies. Nevertheless, the implementation of PGx diagnostics is extremely slow and unequal worldwide, in part due to a lack of ethnic PGx information. We analysed genetic data from 3006 Spanish individuals obtained by different high-throughput (HT) techniques. Allele frequencies were determined in our population for the main 21 actionable PGx genes associated with therapeutical changes. We found that 98% of the Spanish population harbours at least one allele associated with a therapeutical change and, thus, there would be a need for a therapeutical change in a mean of 3.31 of the 64 associated drugs. We also identified 326 putative deleterious variants that were not previously related with PGx in 18 out of the 21 main PGx genes evaluated and a total of 7122 putative deleterious variants for the 1045 PGx genes described. Additionally, we performed a comparison of the main HT diagnostic techniques, revealing that after whole genome sequencing, genotyping with the PGx HT array is the most suitable solution for PGx diagnostics. Finally, all this information was integrated in the Collaborative Spanish Variant Server to be available to and updated by the scientific community.

PharmVar GeneFocus: SLCO1B1

The Pharmacogene Variation Consortium (PharmVar) is now providing star (*) allele nomenclature for the highly polymorphic human SLCO1B1 gene encoding the organic anion transporting polypeptide 1B1 (OATP1B1) drug transporter. Genetic variation within the SLCO1B1 gene locus impacts drug transport, which can lead to altered pharmacokinetic profiles of several commonly prescribed drugs. Variable OATP1B1 function is of particular importance regarding hepatic uptake of statins and the risk of statin-associated musculoskeletal symptoms. To introduce this important drug transporter gene into the PharmVar database and serve as a unified reference of haplotype variation moving forward, an international group of gene experts has performed an extensive review of all published SLCO1B1 star alleles. Previously published star alleles were self-assigned by authors and only loosely followed the star nomenclature system that was first developed for cytochrome P450 genes. This nomenclature system has been standardized by PharmVar and is now applied to other important pharmacogenes such as SLCO1B1. In addition, data from the 1000 Genomes Project and investigator-submitted data were utilized to confirm existing haplotypes, fill knowledge gaps, and/or define novel star alleles. The PharmVar-developed SLCO1B1 nomenclature has been incorporated by the Clinical Pharmacogenetics Implementation Consortium (CPIC) 2022 guideline on statin-associated musculoskeletal symptoms.

Functional Characterization of Six SLCO1B1 (OATP1B1) Variants Observed in Finnish Individuals with a Psychotic Disorder

Variants in the SLCO1B1 (solute carrier organic anion transporter family member 1B1) gene encoding the OATP1B1 (organic anion transporting polypeptide 1B1) protein are associated with altered transporter function that can predispose patients to adverse drug effects with statin treatment. We explored the effect of six rare SLCO1B1 single nucleotide variants (SNVs) occurring in Finnish individuals with a psychotic disorder on expression and functionality of the OATP1B1 protein. The SUPER-Finland study has performed exome sequencing on 9381 individuals with at least one psychotic episode during their lifetime. SLCO1B1 SNVs were annotated with PHRED-scaled combined annotation-dependent (CADD) scores and the Ensembl variant effect predictor. In vitro functionality studies were conducted for the SNVs with a PHRED-scaled CADD score of >10 and predicted to be missense. To estimate possible changes in transport activity caused by the variants, transport of 2',7'-dichlorofluorescein (DCF) in OATP1B1-expressing HEK293 cells was measured. According to the findings, additional tests with rosuvastatin and estrone sulfate were conducted. The amount of OATP1B1 in crude membrane fractions was quantified using a liquid chromatography tandem mass spectrometry-based quantitative targeted absolute proteomics analysis. Six rare missense variants of SLCO1B1 were identified in the study population, located in transmembrane helix 3: c.317T>C (p.106I>T), intracellular loop 2: c.629G>T (p.210G>V), c.633A>G (p.211I>M), c.639T>A (p.213N>L), transmembrane helix 6: 820A>G (p.274I>V), and the C-terminal end: 2005A>C (p.669N>H). Of these variants, SLCO1B1 c.629G>T (p.210G>V) resulted in the loss of in vitro function, abolishing the uptake of DCF, estrone sulfate, and rosuvastatin and reducing the membrane protein expression to 31% of reference OATP1B1. Of the six rare missense variants, SLCO1B1 c.629G>T (p.210G>V) causes a loss of function of OATP1B1 transport in vitro and severely decreases membrane protein abundance. Carriers of SLCO1B1 c.629G>T might be susceptible to altered pharmacokinetics of OATP1B1 substrate drugs and might have increased likelihood of adverse drug effects such as statin-associated musculoskeletal symptoms.

Potential Impact of Pharmacogenomic Single Nucleotide Variants in a Rural Caucasian Population

BACKGROUND

In the US adverse drug reactions (ADRs) are estimated to cause 100 000 fatalities and cost over $136 billion annually. A patient's genes play a significant role in their response to a drug. Pharmacogenomics aims to optimize drug choice and dose for individual patients by characterizing patients' pharmacologically relevant genes to identify variants of known impact.

METHODS

DNA was extracted from randomly selected remnant whole blood samples from Caucasian patients with previously performed complete blood counts. Samples were genotyped by mass spectrometry using a customized pharmacogenomics panel. A third-party result interpretation service used genotypic results to predict likely individual responses to frequently prescribed drugs.

RESULTS

Complete genotypic and phenotypic calls for all tested Cytochrome P450 isoenzymes and other genes were obtained from 152 DNA samples. Of these 152 unique genomic DNA samples, 140 had genetic variants suggesting dose adjustment for at least one drug. Cardiovascular and psychiatry drugs had the highest number of recommendations, which included United States Food and Drug Administration warnings for highly prescribed drugs metabolized by CYP2C19, CYP2C9, CYP2D6, HLA-A, and VKORC1.

CONCLUSIONS

Risk for each drug:gene pairing primarily depends upon the degree of predicted enzyme impairment or activation, width of the therapeutic window, and whether parent compound or metabolite is pharmacologically active. The resulting metabolic variations range from risk of toxicity to therapeutic failure. Pharmacogenomic profiling likely reduces ADR potential by allowing up front drug/dose selection to fit a patient's unique drug-response profile.

A retrospective analysis of preemptive pharmacogenomic testing in 22,918 individuals from China

BACKGROUND

Pharmacogenomics (PGx) examines the influence of genetic variation on drug responses. With more and more Clinical Pharmacogenetics Implementation Consortium (CPIC) guidelines published, PGx is gradually shifting from the reactive testing of single gene toward the preemptive testing of multiple genes. But the profile of PGx genes, especially for the intra-country diversity, is not well understood in China.

METHODS

We retrospectively collected preemptive PGx testing data of 22,918 participants from 20 provinces of China, analyzed frequencies of alleles, genotypes and phenotypes of pharmacogenes, predicted drug responses for each participant, and performed comparisons between different provinces.

RESULTS AND CONCLUSION

After analyzing 15 pharmacogenes from CPIC guidelines of 31 drugs, we found that 99.97% of individuals may have an atypical response to at least one drug; the participants carry actionable genotypes leading to atypical dosage recommendation for a median of eight drugs. Over 99% of the participants were recommended a decreased warfarin dose based on genetic factors. There were 20 drugs with high-risk ratios from 0.18% to 58.25%, in which clopidogrel showed the highest high-risk ratio. In addition, the high-risk ratio of rasburicase in GUANGDONG (risk ratio (RR) = 13.17, 95%CI:4.06-33.22, p < 0.001) and GUANGXI (RR = 23.44, 95%CI:8.83-52.85, p < 0.001) were significantly higher than that in all provinces. Furthermore, the diversity we observed among 20 provinces suggests that preemptive PGx testing in different geographical regions in China may need to pay more attention to specific genes. These results emphasize the importance of preemptive PGx testing and provide essential evidence for promoting clinical implementation in China.

Development of population pharmacokinetics model and Bayesian estimation of rifampicin exposure in Indonesian patients with tuberculosis

BACKGROUND

Interindividual variability in the pharmacokinetics (PK) of anti-tuberculosis (TB) drugs is the leading cause of treatment failure. Herein, we evaluated the influence of demographic, clinical, and genetic factors that cause variability in RIF PK parameters in Indonesian TB patients.

METHODS

In total, 210 Indonesian patients with TB (300 plasma samples) were enrolled in this study. Clinical data, solute carrier organic anion transporter family member-1B1 (SLCO1B1) haplotypes *1a, *1b, and *15, and RIF concentrations were analyzed. The population PK model was developed using a non-linear mixed effect method.

RESULTS

A one-compartment model with allometric scaling adequately described the PK of RIF. Age and SLCO1B1 haplotype *15 were significantly associated with variability in apparent clearance (CL/F). For patients in their 40s, each 10-year increase in age was associated with a 10% decrease in CL/F (7.85 L/h). Patients with the SLCO1B1 haplotype *15 had a 24% lower CL/F compared to those with the wild-type. Visual predictive checks and non-parametric bootstrap analysis indicated good model performance.

CONCLUSION

Age and SLCO1B1 haplotype *15 were significant covariates of RIF CL/F. Geriatric patients with haplotype *15 had significantly greater exposure to RIF. The model could optimize TB pharmacotherapy through its application in therapeutic drug monitoring (clinical trial no. NCT05280886).

Predictive Value of SLCO1B1 c.521T>C Polymorphism on Observed Changes in the Treatment of 1136 Statin-Users

Pharmacogenomic testing is a method to prevent adverse drug reactions. Pharmacogenomics could be relevant to optimize statin treatment, by identifying patients at high risk for adverse drug reactions. We aim to investigate the clinical validity and utility of pre-emptive pharmacogenomics screening in primary care, with SLCO1B1 c.521T>C as a risk factor for statin-induced adverse drug reactions. The focus was on changes in therapy as a proxy for adverse drug reactions observed in statin-users in a population-based Dutch cohort. In total, 1136 statin users were retrospectively genotyped for the SLCO1B1 c.521T>C polymorphism (rs4149056) and information on their statin dispensing was evaluated as cross-sectional research. Approximately half of the included participants discontinued or switched their statin treatment within three years. In our analyses, we could not confirm an association between the SLCO1B1 c.521T>C genotype and any change in statin therapy or arriving at a stable dose sooner in primary care. To be able to evaluate the predictive values of SLCO1B1 c.521T>C genotype on adverse drug reactions from statins, prospective data collection of actual adverse drug reactions and reasons to change statin treatment should be facilitated.

Bioaccumulation and biotransformation of simvastatin in probiotic bacteria: A step towards better understanding of drug-bile acids-microbiome interactions

Introduction: Although pharmacogenetics and pharmacogenomics have been at the forefront of research aimed at finding novel personalized therapies, the focus of research has recently extended to the potential of intestinal microbiota to affect drug efficacy. Complex interplay of gut microbiota with bile acids may have significant repercussions on drug pharmacokinetics. However, far too little attention has been paid to the potential implication of gut microbiota and bile acids in simvastatin response which is characterized by large interindividual variations. The Aim: In order to gain more insight into the underlying mechanism and its contribution in assessing the clinical outcome, the aim of our study was to examine simvastatin bioaccumulation and biotransformation in probiotic bacteria and the effect of bile acids on simvastatin bioaccumulation in in vitro conditions. Materials and methods: Samples with simvastatin, probiotic bacteria and three different bile acids were incubated at anaerobic conditions at 37°C for 24 h. Extracellular and intracellular medium samples were collected and prepared for the LC-MS analysis at predetermined time points (0 min, 15 min, 1 h, 2 h, 4 h, 6 h, 24 h). The concentrations of simvastatin were analyzed by LC-MS/MS. Potential biotransformation pathways were analyzed using a bioinformatics approach in correlation with experimental assay. Results: During the incubation, simvastatin was transported into bacteria cells leading to a drug bioaccumulation over the time, which was augmented upon addition of bile acids after 24 h. A decrease of total drug level during the incubation indicates that the drug is partly biotransformed by bacterial enzymes. According to the results of bioinformatics analysis, the lactone ring is the most susceptible to metabolic changes and the most likely reactions include ester hydrolysis followed by hydroxylation. Conclusion: Results of our study reveal that bioaccumulation and biotransformation of simvastatin by intestinal bacteria might be the underlying mechanisms of altered simvastatin bioavailability and therapeutic effect. Since this study is based only on selected bacterial strains in vitro, further more in-depth research is needed in order to elicit completely the contribution of complex drug-microbiota-bile acids interactions to overall clinical response of simvastatin which could ultimately lead to novel approaches for the personalized lipid-lowering therapy.

Genetic Variation in CYP2D6 and SLC22A1 Affects Amlodipine Pharmacokinetics and Safety

Amlodipine is an antihypertensive drug with unknown pharmacogenetic biomarkers. This research is a candidate gene study that looked for associations between amlodipine pharmacokinetics and safety and pharmacogenes. Pharmacokinetic and safety data were taken from 160 volunteers from eight bioequivalence trials. In the exploratory step, 70 volunteers were genotyped for 44 polymorphisms in different pharmacogenes. CYP2D6 poor metabolizers (PMs) showed higher half-life (t1/2) (univariate p-value (puv) = 0.039, multivariate p-value (pmv) = 0.013, β = -5.31, R2 = 0.176) compared to ultrarapid (UMs), normal (NMs) and intermediate metabolizers (IMs). SLC22A1 rs34059508 G/A genotype was associated with higher dose/weight-corrected area under the curve (AUC72/DW) (puv = 0.025; pmv = 0.026, β = 578.90, R2 = 0.060) compared to the G/G genotype. In the confirmatory step, the cohort was increased to 160 volunteers, who were genotyped for CYP2D6, SLC22A1 and CYP3A4. In addition to the previous associations, CYP2D6 UMs showed a lower AUC72/DW (puv = 0.046, pmv = 0.049, β = -68.80, R2 = 0.073) compared to NMs, IMs and PMs and the SLC22A1 rs34059508 G/A genotype was associated with thoracic pain (puv = 0.038) and dizziness (puv = 0.038, pmv = 0.014, log OR = 10.975). To our knowledge, this is the first work to report a strong relationship between amlodipine and CYP2D6 and SLC22A1. Further research is needed to gather more evidence before its application in clinical practice.

Pharmacogenomic testing and prescribing patterns for patients with cancer in a large national precision medicine cohort

Population databases could help patients with cancer and providers better understand current pharmacogenomic prescribing and testing practices. This retrospective observational study analysed patients with cancer, drugs with pharmacogenomic evidence and related genetic testing in the National Institutes of Health All of Us database. Most patients with cancer (19 633 (88.3%) vs 2590 (11.7%)) received ≥1 drug and 36 (0.2%) received genetic testing, with a significant association between receiving ≥1 drug and age group (p<0.001), but not sex (p=0.612), race (p=0.232) or ethnicity (p=0.971). Drugs with pharmacogenomic evidence-but not genetic testing-were common for patients with cancer, reflecting key gaps preventing precision medicine from becoming standard of care.

Genetic predictors of lifelong medication-use patterns in cardiometabolic diseases

Little is known about the genetic determinants of medication use in preventing cardiometabolic diseases. Using the Finnish nationwide drug purchase registry with follow-up since 1995, we performed genome-wide association analyses of longitudinal patterns of medication use in hyperlipidemia, hypertension and type 2 diabetes in up to 193,933 individuals (55% women) in the FinnGen study. In meta-analyses of up to 567,671 individuals combining FinnGen with the Estonian Biobank and the UK Biobank, we discovered 333 independent loci (P < 5 × 10-9) associated with medication use. Fine-mapping revealed 494 95% credible sets associated with the total number of medication purchases, changes in medication combinations or treatment discontinuation, including 46 credible sets in 40 loci not associated with the underlying treatment targets. The polygenic risk scores (PRS) for cardiometabolic risk factors were strongly associated with the medication-use behavior. A medication-use enhanced multitrait PRS for coronary artery disease matched the performance of a risk factor-based multitrait coronary artery disease PRS in an independent sample (UK Biobank, n = 343,676). In summary, we demonstrate medication-based strategies for identifying cardiometabolic risk loci and provide genome-wide tools for preventing cardiovascular diseases.

Case report: Hepatotoxicity and nephrotoxicity induced by methotrexate in a paediatric patient, what is the role of precision medicine in 2023?

Methotrexate is an immunosuppressant and chemotherapeutic agent used in the treatment of a range of autoimmune disorders and cancers. Its main serious adverse effects, bone marrow suppression and gastrointestinal complications, arise from its antimetabolite effect. Nevertheless, hepatotoxicity and nephrotoxicity are two widely described adverse effects of methotrexate. Its hepatotoxicity has been studied mainly in the low-dose, chronic setting, where patients are at risk of fibrosis/cirrhosis. Studies of acute hepatoxicity of high dose methotrexate, such as during chemotherapy, are scarce. We present the case of a 14-year-old patient who received high-dose methotrexate and subsequently developed acute fulminant liver failure and acute kidney injury. Genotyping of MTHFR (Methylene tetrahydrofolate reductase gene), ABCB1 (codes for P-glycoprotein, intestinal transport and biliary excretion), ABCG2 (codes for BCRP, intestinal transporter and renal excretion) and SLCO1B1 (codes for OATP1B1, hepatic transporter) identified variants in all the genes analysed that predicted a reduced rate of methotrexate elimination and thus may have contributed to the clinical situation of the patient. Precision medicine involving pharmacogenomic testing could potentially avoid such adverse drug effects.

Which four medication classes have important pharmacogenetic considerations?

ABSTRACT

Medications often are prescribed without knowledge of a patient's pharmacogenetic profile. Initial therapy may require subsequent modification due to adverse reactions or lack of efficacy. Although many variables, including changes in pharmacokinetics, pharmacodynamics, or patient nonadherence, may account for these outcomes, information about a patient's ability to metabolize or transport drugs across membranes may be used to optimize therapy, resulting in improved medication outcomes.

ABCG2 and SLCO1B1 gene polymorphisms in the Croatian population

BACKGROUND

Organic anion-transporting polypeptide 1B1 (OATP1B1) and the ATP-binding cassette subfamily G member 2, ABCG2, are important transporters involved in the transport of endogenous substrates and xenobiotics, including drugs. Genetic polymorphisms of these transporters have effect on transporter activity. There is significant interethnic variability in the frequency of allele variants.

AIM

To determined allele and genotype frequencies of ABCG2 and SLCO1B1 genes in Croatian populations of European descent.

SUBJECTS AND METHODS

A total of 905 subjects (482 women) were included. Genotyping for ABCG2 c.421C > A (rs2231142) and for SLCO1B1 c.521T > C (rs4149056), was performed by real-time polymerase chain reaction (PCR) using TaqMan^® DME Genotyping Assays.

RESULTS

For ABCG2 c.421C > A, the frequency of CC, CA and AA genotypes was 81.4%, 17.8% and 0.8% respectively. The frequency of variant ABCG2 421 A allele was 9.7%. For SLCO1B1 c.521T > C, the frequency of TT, TC and CC genotypes was 61.7%, 34.8% and 3.5% respectively. The frequency of variant SLCO1B1 521 C allele was 20.9%.

CONCLUSION

The frequency of the ABCG2 and SLCO1B1 allelic variants and genotypes in the Croatian population is in accordance with other European populations. Pharmacogenetic analysis can serve to individualise drug therapy and minimise the risk of developing adverse drug reactions.

SLCO1B1 c.521T>C gene polymorphism decreases hypoglycemia risk in sulfonylurea-treated type 2 diabetic patients

OBJECTIVES

Pharmacogenomics can explain some of the heterogeneity of sulfonylurea (SU)-related hypoglycemia risk. Recently, a role of OATP1B1, encoded by SLCO1B1 gene, on SU liver transport prior of metabolism has been uncovered. The aim of the present study was to explore the potential association of SLCO1B1 c.521T>C polymorphism, leading to reduced OATP1B1 function, with SU-related hypoglycemia risk.

METHODS

Study cohort consists of 176 type 2 diabetes patients treated with the SUs glimepiride or gliclazide. 92 patients reported SU-related hypoglycemia, while 84 patients had never experienced a hypoglycemic event. Patients were previously genotyped for CYP2C9 *2 and *3 variant alleles that lead to decreased enzyme activity of the SU metabolizing enzyme CYP2C9 and have been associated with increased SU-related hypoglycemia risk. SLCO1B1 c.521T>C polymorphism was genotyped by use of PCR-RFLP analysis.

RESULTS

SLCO1B1 c.521TC genotype frequency was significantly lower in hypoglycemic cases than non-hypoglycemic controls (15.2% vs. 32.1%, p=0.008). In an adjusted model, c.521TC genotype significantly reduced the risk of hypoglycemia (OR 0.371; 95% C.I. 0.167-0.822; p=0.015). In CYP2C9 intermediate metabolizers (n=54) c.521TC genotype frequency was significantly decreased in cases compared to controls (3 out of 36 cases, 8.3% vs. 7 out of 18 controls, 38.9%, p=0.012). A similar albeit not significant difference of SLCO1B1 c.521TC genotype was present in CYP2C9 extensive metabolizers (n=120) (18.2% in cases vs. 30.8% in controls, p=0.113).

CONCLUSIONS

We have found a protective effect of SLCO1B1 c.521C variant on SU-related hypoglycemia risk both independently and in interaction with CYP2C9 phenotypes. Our results suggest a possible linkage of SLCO1B1 c.521T>C polymorphism with variants in other genes impairing OATPs expressed in pancreatic islets that could interfere with SU tissue distribution.

Effects of SLCO1B1 Genetic Variant on Metabolite Profile in Participants on Simvastatin Treatment

Organic-anion-transporting polypeptide 1B1 (OATP1B1), encoded by the solute carrier organic anion transporter family member 1B1 gene (SLCO1B1), is highly expressed in the liver and transports several endogenous metabolites into the liver, including statins. Previous studies have not investigated the association of SLCO1B1 rs4149056 variant with the risk of type 2 diabetes (T2D) or determined the metabolite signature of the C allele of SLCO1B1 rs4149056 (SLCO1B1 rs4149056-C allele) in a large randomly selected population. SLCO1B1 rs4149056-C inhibits OATP1B1 transporter and is associated with increased levels of blood simvastatin concentrations. Our study is to first to show that SLCO1B1 rs4149056 variant is not significantly associated with the risk of T2D, suggesting that simvastatin has a direct effect on the risk of T2D. Additionally, we investigated the effects of SLCO1B1 rs4149056-C on plasma metabolite concentrations in 1373 participants on simvastatin treatment and in 1368 age- and body-mass index (BMI)-matched participants without any statin treatment. We found 31 novel metabolites significantly associated with SLCO1B1 rs4149056-C in the participants on simvastatin treatment and in the participants without statin treatment. Simvastatin decreased concentrations of dicarboxylic acids, such as docosadioate and dodecanedioate, that may increase beta- and peroxisomal oxidation and increased the turnover of cholesterol into bile acids, resulting in a decrease in steroidogenesis due to limited availability of cholesterol for steroid synthesis. Our findings suggest that simvastatin exerts its effects on the lowering of low-density lipoprotein (LDL) cholesterol concentrations through several distinct pathways in the carriers of SLCO1B1 rs4149056-C, including dicarboxylic acids, bile acids, steroids, and glycerophospholipids.

CYP2C8*3 and *4 define CYP2C8 phenotype: An approach with the substrate cinitapride

Cinitapride is a gastrointestinal prokinetic drug, prescribed for the treatment of functional dyspepsia, and as an adjuvant therapy for gastroesophageal reflux disease. In this study, we aimed to explore the impact of relevant variants in CYP3A4 and CYP2C8 and other pharmacogenes, along with demographic characteristics, on cinitapride pharmacokinetics and safety; and to evaluate the impact of CYP2C8 alleles on the enzyme's function. Twenty-five healthy volunteers participating in a bioequivalence clinical trial consented to participate in the study. Participants were genotyped for 56 variants in 19 genes, including cytochrome P450 (CYP) enzymes (e.g., CYP2C8 or CYP3A4) or transporters (e.g., SLC or ABC), among others. CYP2C8*3 carriers showed a reduction in AUC of 42% and Cmax of 35% compared to *1/*1 subjects (p = 0.003 and p = 0.011, respectively). *4 allele carriers showed a 45% increase in AUC and 63% in Cmax compared to *1/*1 subjects, although these differences did not reach statistical significance. CYP2C8*3 and *4 alleles may be used to infer the following pharmacogenetic phenotypes: ultrarapid (UM) (*3/*3), rapid (RM) (*1/*3), normal (NM) (*1/*1), intermediate (IM) (*1/*4), and poor (PM) metabolizers (*4/*4). In this study, we properly characterized RMs, NMs, and IMs; however, additional studies are required to properly characterize UMs and PMs. These findings should be relevant with respect to cinitapride, but also to numerous CYP2C8 substrates such as imatinib, loperamide, montelukast, ibuprofen, paclitaxel, pioglitazone, repaglinide, or rosiglitazone.

Barriers to genetic testing in clinical psychiatry and ways to overcome them: from clinicians' attitudes to sociocultural differences between patients across the globe

Genetic testing has evolved rapidly over recent years and new developments have the potential to provide insights that could improve the ability to diagnose, treat, and prevent diseases. Information obtained through genetic testing has proven useful in other specialties, such as cardiology and oncology. Nonetheless, a range of barriers impedes techniques, such as whole-exome or whole-genome sequencing, pharmacogenomics, and polygenic risk scoring, from being implemented in psychiatric practice. These barriers may be procedural (e.g., limitations in extrapolating results to the individual level), economic (e.g., perceived relatively elevated costs precluding insurance coverage), or related to clinicians' knowledge, attitudes, and practices (e.g., perceived unfavorable cost-effectiveness, insufficient understanding of probability statistics, and concerns regarding genetic counseling). Additionally, several ethical concerns may arise (e.g., increased stigma and discrimination through exclusion from health insurance). Here, we provide an overview of potential barriers for the implementation of genetic testing in psychiatry, as well as an in-depth discussion of strategies to address these challenges.

Frequency of functional exonic single-nucleotide polymorphisms and haplotype distribution in the SLCO1B1 gene across genetic ancestry groups in the Qatari population

Organic anion transporting polypeptides (OATP), which are encoded by SLCO genes, participate in the hepatic elimination of drugs and xenobiotics. SLCO1B1 is an important pharmacogenomic gene (encoding OATP1B1) associated with response to the uptake of endogenous compounds, such as statin and bilirubin. Ethnicity of the patient modulates the response to these drugs; the frequency and haplotype data for SLCO1B1 genetic variants in the Arab population is lacking. Therefore, we determined the frequencies of two well-characterized SLCO1B1 single nucleotide polymorphisms (SNP) and haplotypes that affect the OATP1B1 drugs transportation activity in Qatari population. Genotyping data for two SLCO1B1 SNPs (c.388A > G, c.521 T > C) were extracted from whole exome data of 1050 Qatari individuals, who were divided into three ancestry groups, namely Bedouins, Persians/South Asians, and Africans. By way of using Fisher's exact and Chi-square tests, we evaluated the differences in minor allele frequency (MAF) of the two functional SNPs and haplotype frequencies (HF) among the three ancestry groups. The OATP1B1 phenotypes were assigned according to their function by following the guidelines from the Clinical Pharmacogenetics Implementation Consortium for SLCO1B1 and Simvastatin-Induced Myopathy.The MAF of SLCO1B1:c.388A > G was higher compared to that of SLCO1B1:c.521 T > C in the study cohort. It was significantly high in the African ancestry group compared with the other two groups, whereas SLCO1B1:c.521 T > C was significantly low in the African ancestry group compared with the other two groups. The SLCO1B1 *15 haplotype had the highest HF, followed by *1b, *1a, and *5. Only the SLCO1B1 *5 haplotype showed no significant difference in frequency across the three ancestry groups. Furthermore, we observed that the OATP1B1 normal function phenotype accounted for 58% of the Qatari individuals, the intermediate function phenotype accounted for 35% with significant differences across the ancestry groups, and the low function phenotype accounted for 6% of the total Qatari individuals with a higher trend observed in the Bedouin group.The results indicate that the phenotype frequencies of the OATP1B1 intermediate and low function in the Qatari population appear at the higher end of the frequency range seen worldwide. Thus, a pharmacogenetic screening program for SLCO1B1 variants may be necessary for the Qatari population.

The role of OATP1B1 and OATP1B3 transporter polymorphisms in drug disposition and response to anticancer drugs: a review of the recent literature

INTRODUCTION

Members of the solute carrier family of organic anion transporting polypeptides are responsible for the cellular uptake of a broad range of endogenous compounds and xenobiotics in multiple tissues. In particular, the polymorphic transporters OATP1B1 and OATP1B3 are highly expressed in the liver and have been identified as critical regulators of hepatic eliminaton. As these transporters are also expressed in cancer cells, the function alteration of these proteins have important consequences for an individual's susceptibility to certain drug-induced side effects, drug-drug interactions, and treatment efficacy.

AREAS COVERED

In this mini-review, we provide an update of this rapidly emerging field, with specific emphasis on the direct contribution of genetic variants in OATP1B1 and OATP1B3 to the transport of anticancer drugs, the role of these carriers in regulation of their disposition and toxicity profiles, and recent advances in attempts to integrate information on transport function in patients to derive individualized treatment strategies.

EXPERT OPINION

Based on currently available data, it appears imperative that different aspects of disease, physiology, and drugs of relevance should be evaluated along with an individual's genetic signature, and that tools such as biomarker levels can be implemented to achieve the most reliable prediction of clinically relevant pharmacodynamic endpoints.