Vitaminas B neurotrópicas y neuropatía periférica: estado del arte y acuerdo de expertos

Propósito: La neuropatía periférica tiene un espectro clínico inespecífico y multifactorial, con frecuente subdiagnóstico y terapéutica de eficacia variable. Existe una heterogénea prescripción de vitaminas B, las cuales pueden desempeñar un rol importante en el manejo de diferentes neuropatías; sin embargo, en Colombia no existen guías clínicas al respecto. El propósito de este trabajo es orientar en el reconocimiento temprano de las neuropatías periféricas y generar recomendaciones sobre el uso adecuado de vitaminas B neurotrópicas. Descripción de la metodología: Acuerdo de expertos sobre la neuropatía periférica y el rol terapéutico de las vitaminas B con énfasis en la epidemiología en Colombia, diagnóstico y tratamiento. Contenidos: En Colombia, la prevalencia de neuropatía periférica se estima cercana al 10 %, sin embargo, no hay datos recientes. Dentro de las etiologías más frecuentes se encuentran la neuropatía diabética, infecciosa, inflamatoria, carenciales, toxica y farmacológica. Se recomiendan las siguientes herramientas de tamizaje en población de riesgo: DN4, MNSI, test de monofilamento, test de vibración y valoración de reflejos. Las vitaminas B1, B6 y B12 son seguras, accesibles y pueden ser eficaces en neuropatía periférica, incluso cuando el déficit no ha sido demostrado, pero con requerimientos particulares en su administración conjunta. Conclusiones: Las neuropatías periféricas son un reto diagnóstico y terapéutico que requiere la identificación oportuna para el tratamiento de la etiología subyacente y el control de síntomas. El uso de vitaminas B neurotrópicas es efectivo y seguro en neuropatía periférica carencial, y también parece ser eficaz en el manejo de neuropatías periféricas de diferentes etiologías.

Purpose: Peripheral neuropathy has a nonspecific and multifactorial clinical spectrum, with frequent underdiagnosis and therapeutics of variable efficacy. There is a high but heterogeneous prescription of B vitamins, which can play an important role in the management of different neuropathies; however, in Colombia there are no clinical guidelines in this regard. The purpose of this article is to guide the early recognition of peripheral neuropathy and generate recommendations on the proper use of neurotropic B vitamins. Description of the methodology: Expert agreement on peripheral neuropathy and the therapeutic role of B vitamins with emphasis on epidemiology in Colombia, diagnosis and treatment. Contents: In Colombia, there are no recent data to estimate the prevalence of peripheral neuropathy; the main etiologies are: diabetes mellitus, nutritional deficiencies, herpes zoster and neuropathies due to chemotherapy. Given risk factors in the anamnesis, the use of DN4, MNSI, monofilament test, vibration test and assessment of reflexes is recommended. Vitamins B1, B6, and B12 are safe and can be effective in peripheral neuropathy, even when the deficit has not been demonstrated, but with special requirements in their joint administration. Conclusions: peripheral neuropathies are a diagnostic and therapeutic challenge, and require timely identification, for the treatment of the underlying etiology and symptom control. The use of neurotropic B vitamins is effective and safe in deficient peripheral neuropathy, and also appears to be effective in the management of peripheral neuropathies of different etiologies.

Making Sense of Composite Endpoints in Clinical Research.

Multiple drugs currently used in clinical practice have been approved by regulatory agencies based on studies that utilize composite endpoints. Composite endpoints are appealing because they reduce sample size requirements, follow-up periods, and costs. However, interpreting composite endpoints can be challenging, and their misuse is not uncommon. Incorrect interpretation of composite outcomes can lead to misleading conclusions that impact patient care. To correctly interpret composite outcomes, several important questions should be considered. Are the individual components of the composite outcome equally important to patients? Did the more and less important endpoints occur with similar frequency? Do the component endpoints exhibit similar relative risk reductions? If these questions receive affirmative answers, the use and interpretation of the composite endpoint would be appropriate. However, if any component of the composite endpoint fails to satisfy the aforementioned criteria, interpretation can become difficult, necessitating additional steps. Regulatory agencies acknowledge these challenges and have specific considerations when approving drugs based on studies employing composite endpoints. In conclusion, composite endpoints are valuable tools for evaluating the efficacy and net clinical benefit of interventions; however, cautious interpretation is advised.

Development of Antiepileptic Drugs throughout History: From Serendipity to Artificial Intelligence.

This article provides a comprehensive narrative review of the history of antiepileptic drugs (AEDs) and their development over time. Firstly, it explores the significant role of serendipity in the discovery of essential AEDs that continue to be used today, such as phenobarbital and valproic acid. Subsequently, it delves into the historical progression of crucial preclinical models employed in the development of novel AEDs, including the maximal electroshock stimulation test, pentylenetetrazol-induced test, kindling models, and other animal models. Moving forward, a concise overview of the clinical advancement of major AEDs is provided, highlighting the initial milestones and the subsequent refinement of this process in recent decades, in line with the emergence of evidence-based medicine and the implementation of increasingly rigorous controlled clinical trials. Lastly, the article explores the contributions of artificial intelligence, while also offering recommendations and discussing future perspectives for the development of new AEDs.

Pharmacogenomic profile of actionable molecular variants related to drugs commonly used in anesthesia: WES analysis reveals new mutations.

Background: Genetic interindividual variability is associated with adverse drug reactions (ADRs) and affects the response to common drugs used in anesthesia. Despite their importance, these variants remain largely underexplored in Latin-American countries. This study describes rare and common variants found in genes related to metabolism of analgesic and anaesthetic drug in the Colombian population. Methods: We conducted a study that included 625 Colombian healthy individuals. We generated a subset of 14 genes implicated in metabolic pathways of common medications used in anesthesia and assessed them by whole-exome sequencing (WES). Variants were filtered using two pipelines: A) novel or rare (minor allele frequency-MAF <1%) variants including missense, loss-of-function (LoF, e.g., frameshift, nonsense), and splice site variants with potential deleterious effect and B) clinically validated variants described in the PharmGKB (categories 1, 2 and 3) and/or ClinVar databases. For rare and novel missense variants, we applied an optimized prediction framework (OPF) to assess the functional impact of pharmacogenetic variants. Allelic, genotypic frequencies and Hardy-Weinberg equilibrium were calculated. We compare our allelic frequencies with these from populations described in the gnomAD database. Results: Our study identified 148 molecular variants potentially related to variability in the therapeutic response to 14 drugs commonly used in anesthesiology. 83.1% of them correspond to rare and novel missense variants classified as pathogenic according to the pharmacogenetic optimized prediction framework, 5.4% were loss-of-function (LoF), 2.7% led to potential splicing alterations and 8.8% were assigned as actionable or informative pharmacogenetic variants. Novel variants were confirmed by Sanger sequencing. Allelic frequency comparison showed that the Colombian population has a unique pharmacogenomic profile for anesthesia drugs with some allele frequencies different from other populations. Conclusion: Our results demonstrated high allelic heterogeneity among the analyzed sampled, enriched by rare (91.2%) variants in pharmacogenes related to common drugs used in anesthesia. The clinical implications of these results highlight the importance of implementation of next-generation sequencing data into pharmacogenomic approaches and personalized medicine.

A Latin American consensus meeting on the essentials of mixed pain.

OBJECTIVES: The term "mixed pain" has been established when a mixture of different pain components (e.g. nociceptive, neuropathic, and nociplastic) are present. It has gained more and more acceptance amongst pain experts worldwide, but many questions around the concept of mixed pain are still unsolved. The sensation of pain is very personal. Cultural, social, personal experiences, idiomatic, and taxonomic differences should be taken into account during pain assessment. Therefore, a Latin American consensus committee was formed to further elaborate the essentials of mixed pain, focusing on the specific characteristics of the Latin American population. METHODS: The current approach was based on a systematic literature search and review carried out in Medline. Eight topics about the definition, diagnosis, and treatment of mixed pain were discussed and voted for by a Latin American consensus committee and recommendations were expressed. RESULTS: At the end of the meeting a total of 14 voting sheets were collected. The full consensus was obtained for 21 of 25 recommendations (15 strong agreement and 6 unanimous agreement) formulated for the above described 8 topics (7 of the 8 topics had for all questions at least a strong agreement - 1 topic had no agreement for all 4 questions). CONCLUSION: In a subject as complex as mixed pain, a consensus has been reached among Latin American specialists on points related to the definition and essence of this pain, its diagnosis and treatment. Recommendations for diagnosis and treatment of mixed pain in Latin America were raised.

Definition of self-medication: a scoping review.

Self-medication (SM) is a global and growing phenomenon. It represents a public health problem due to antibiotic resistance, risk of adverse drug reactions, drug-drug interactions, disease masking, and increased morbidity. There is not a consensus on the definition of SM. The definitions found in different studies make it difficult to address this problem from a theoretical perspective and therefore find an adequate solution to this public health problem. The aim of this article is to search the medical literature to characterize the current understanding of SM in the medical community. We conducted a scoping review of definitions of SM by searching on PubMed - Medline, Embase, and LILACS using the following combination of keywords: 'self-prescription' or 'self prescription', 'self-medication' or 'self medication', or 'automedication' and 'definition' or 'explanation'. The search was limited to articles containing the definition of SM, with no limit on language or year. Duplicate studies and those that did not mention the definition of SM were excluded from the final review. A total of 65 studies were included in the final selection. We found a vast heterogeneity in the definition of SM. Most articles based their definition of SM on the process of obtaining the drug, the nonparticipation of a specific health professional, the source of the medication, and the reason for SM. Other interesting concepts such as self-care, nonadherence to a prescription, reuse of stored drugs, and sharing and lending medicines were also considered forms of SM by other authors, however. This study highlights the need to reach a consensus regarding the definition of SM to adequately propose strategies to address this global health problem. This study shows the diverse concepts that need to be included in a future definition of SM. Plain Language Summary: Definition of self-medication: a review with systematic methodology Self-medication (SM) is a global and growing phenomenon that represents a public health problem due to antibiotic resistance, risk of dangerous side effects, interactions between drugs, and disease masking. Currently, there is not a consensus on the definition of SM, which makes it difficult to address this problem and therefore find an adequate solution. Making a standard definition would allow the development of programs focused on addressing drug-related problems associated with self-medication behavior. The purpose of this article is to search the medical literature to define the current understanding of SM in the medical community. We included a total of 65 studies and found a great variance in the definition of SM. Most articles based their definition of SM on the process of obtaining the drug, the nonparticipation of a specific health professional, the source of the medication, and the reason for SM. Other interesting concepts such as self-care, not following a prescription, reuse of stored drugs, and sharing and lending medicines were also considered forms of SM by other authors, however. Furthermore, this study highlights that SM is a wider concept that goes beyond aiming to promote and restore health, as aesthetic and recreational purposes are also reasons for SM that can put individuals at risk and compromise the correct and safe use of medications.

Connexins and Pannexins: Important Players in Neurodevelopment, Neurological Diseases, and Potential Therapeutics.

Cell-to-cell communication is essential for proper embryonic development and its dysfunction may lead to disease. Recent research has drawn attention to a new group of molecules called connexins (Cxs) and pannexins (Panxs). Cxs have been described for more than forty years as pivotal regulators of embryogenesis; however, the exact mechanism by which they provide this regulation has not been clearly elucidated. Consequently, Cxs and Panxs have been linked to congenital neurodegenerative diseases such as Charcot-Marie-Tooth disease and, more recently, chronic hemichannel opening has been associated with adult neurodegenerative diseases (e.g., Alzheimer's disease). Cell-to-cell communication via gap junctions formed by hexameric assemblies of Cxs, known as connexons, is believed to be a crucial component in developmental regulation. As for Panxs, despite being topologically similar to Cxs, they predominantly seem to form channels connecting the cytoplasm to the extracellular space and, despite recent research into Panx1 (Pannexin 1) expression in different regions of the brain during the embryonic phase, it has been studied to a lesser degree. When it comes to the nervous system, Cxs and Panxs play an important role in early stages of neuronal development with a wide span of action ranging from cellular migration during early stages to neuronal differentiation and system circuitry formation. In this review, we describe the most recent available evidence regarding the molecular and structural aspects of Cx and Panx channels, their role in neurodevelopment, congenital and adult neurological diseases, and finally propose how pharmacological modulation of these channels could modify the pathogenesis of some diseases.

Thermodynamic Analysis of the Solubility of Isoniazid in (PEG 200 + Water) Cosolvent Mixtures from 278.15 K to 318.15 K.

The solubility of drugs in cosolvent systems of pharmaceutical interest is of great importance for understanding and optimizing a large number of processes. Here, we report the solubility of isoniazid in nine (PEG 200 + water) cosolvent mixtures at nine temperatures (278.15, 283.15, 288.15, 293.15, 298.15, 303.15, 308.15, and 318.15 K) determined by UV-vis spectrophotometry. From the solubility data, the thermodynamic solution, mixing, and transfer functions were calculated in addition to performing the enthalpy-entropy compensation analysis. The solubility of isoniazid depends on the concentration of PEG 200 (positive cosolvent effect) and temperature (endothermic process) reaching its maximum solubility in pure PEG 200 at 318.15 K and the lowest solubility in pure water at 278.15 K. The solution process is favored by the solution entropy and according to the enthalpy-entropy compensation analysis it is driven by entropy in mixtures rich in water and by enthalpy in mixtures rich in PEG 200.

Immune-related adverse events of biological immunotherapies used in COVID-19.

The use of biological immunotherapeutic drugs is one of the options currently being evaluated and employed to manage COVID-19, specifically monoclonal antibodies, which have shown benefit by regulating the excessive immune response seen in patients with severe infection, known as a cytokine storm. Tocilizumab has received particular importance for this clinical application, as has sarilumab. Both drugs share a substantial similarity in terms of pharmacodynamics, being inhibitors of the interleukin six receptor (IL-6Rα). Furthermore, sotrovimab, a neutralizing anti-SARS CoV-2 antibody, has gained the attention of the scientific community since it has recently been authorized under certain circumstances, positioning itself as a new therapeutic alternative in development. However, despite their clinical benefit, biological immunotherapies have the potential to generate life-threatening immune-related adverse events. Therefore it is essential to review their incidence, mechanism, and risk factors. This review aims to provide a comprehensive understanding of the safety of the biological immunotherapeutic drugs currently recommended for the treatment of COVID-19, provide a review of the known immune-mediated adverse events and explore the potential immune-related mechanisms of other adverse reactions.

Type III Kounis Syndrome Secondary to Ciprofloxacin-Induced Hypersensitivity.

Kounis syndrome (KS) is a rare syndrome characterized by the co-occurrence of acute coronary syndromes in the setting of mast cell and platelet activation in response to hypersensitivity reactions. It can be manifested as coronary vasospasms, acute myocardial infarction, or stent thrombosis triggered by drugs, vaccines, foods, coronary stents, and insect bites. It is a life-threatening condition that needs to be adequately recognized for early diagnosis and appropriate treatment. In this case report, we present a 71-year-old patient with a history of arterial hypertension and non-ST elevation myocardial infarction six months earlier that was treated percutaneously with angioplasty plus stent implantation in the circumflex artery, who subsequently presented to the emergency department due to generalized itching associated with tongue swelling, dyspnea, and chest pain after ingestion of ciprofloxacin for the treatment of a urogenital infection. An electrocardiogram showed ST elevation in II, III, and aVF leads, and positive troponin; thus, a coronary arteriography was performed that showed complete thrombotic stent occlusion in the circumflex artery. Consequently, diagnosis of type 4b inferolateral acute myocardial infarction secondary to ciprofloxacin-triggered type III Kounis syndrome was made. The aim of this report is to understand the relationship between the allergic reaction to ciprofloxacin and the acute coronary syndrome, and to create awareness of the importance of early diagnosis and treatment of this potentially fatal syndrome.

Prescription for COVID-19 by non-medical professionals during the pandemic in Colombia: a cross-sectional study.

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.

Therapeutic Drug Monitoring of Antifungal Agents in Critically Ill Patients: Is There a Need for Dose Optimisation?

Invasive fungal infections are an important cause of morbidity and mortality, especially in critically ill patients. Increasing resistance rates and inadequate antifungal exposure have been documented in these patients, due to clinically relevant pharmacokinetic (PK) and pharmacodynamic (PD) alterations, leading to treatment failure. Physiological changes such as third spacing (movement of fluid from the intravascular compartment to the interstitial space), hypoalbuminemia, renal failure and hepatic failure, as well as common interventions in the intensive care unit, such as renal replacement therapy and extracorporeal membrane oxygenation, can lead to these PK and PD alterations. Consequently, a therapeutic target concentration that may be useful for one patient may not be appropriate for another. Regular doses do not take into account the important PK variations in the critically ill, and the need to select an effective dose while minimising toxicity advocates for the use of therapeutic drug monitoring (TDM). This review aims to describe the current evidence regarding optimal PK/PD indices associated with the clinical efficacy of the most commonly used antifungal agents in critically ill patients (azoles, echinocandins, lipid complexes of amphotericin B, and flucytosine), provide a comprehensive understanding of the factors affecting the PK of each agent, document the PK parameters of critically ill patients compared to healthy volunteers, and, finally, make recommendations for therapeutic drug monitoring (TDM) of antifungals in critically ill patients.

Revisiting Excitotoxicity in Traumatic Brain Injury: From Bench to Bedside.

Traumatic brain injury (TBI) is one of the leading causes of morbidity and mortality. Consequences vary from mild cognitive impairment to death and, no matter the severity of subsequent sequelae, it represents a high burden for affected patients and for the health care system. Brain trauma can cause neuronal death through mechanical forces that disrupt cell architecture, and other secondary consequences through mechanisms such as inflammation, oxidative stress, programmed cell death, and, most importantly, excitotoxicity. This review aims to provide a comprehensive understanding of the many classical and novel pathways implicated in tissue damage following TBI. We summarize the preclinical evidence of potential therapeutic interventions and describe the available clinical evaluation of novel drug targets such as vitamin B12 and ifenprodil, among others.

Machine Learning for Prediction of Stable Warfarin Dose in US Latinos and Latin Americans.

Populations used to create warfarin dose prediction algorithms largely lacked participants reporting Hispanic or Latino ethnicity. While previous research suggests nonlinear modeling improves warfarin dose prediction, this research has mainly focused on populations with primarily European ancestry. We compare the accuracy of stable warfarin dose prediction using linear and nonlinear machine learning models in a large cohort enriched for US Latinos and Latin Americans (ULLA). Each model was tested using the same variables as published by the International Warfarin Pharmacogenetics Consortium (IWPC) and using an expanded set of variables including ethnicity and warfarin indication. We utilized a multiple linear regression model and three nonlinear regression models: Bayesian Additive Regression Trees, Multivariate Adaptive Regression Splines, and Support Vector Regression. We compared each model's ability to predict stable warfarin dose within 20% of actual stable dose, confirming trained models in a 30% testing dataset with 100 rounds of resampling. In all patients (n = 7,030), inclusion of additional predictor variables led to a small but significant improvement in prediction of dose relative to the IWPC algorithm (47.8 versus 46.7% in IWPC, p = 1.43 × 10-15). Nonlinear models using IWPC variables did not significantly improve prediction of dose over the linear IWPC algorithm. In ULLA patients alone (n = 1,734), IWPC performed similarly to all other linear and nonlinear pharmacogenetic algorithms. Our results reinforce the validity of IWPC in a large, ethnically diverse population and suggest that additional variables that capture warfarin dose variability may improve warfarin dose prediction algorithms.

Genetic and Molecular Aspects of Drug-Induced QT Interval Prolongation.

Long QT syndromes can be either acquired or congenital. Drugs are one of the many etiologies that may induce acquired long QT syndrome. In fact, many drugs frequently used in the clinical setting are a known risk factor for a prolonged QT interval, thus increasing the chances of developing torsade de pointes. The molecular mechanisms involved in the prolongation of the QT interval are common to most medications. However, there is considerable inter-individual variability in drug response, thus making the application of personalized medicine a relevant aspect in long QT syndrome, in order to evaluate the risk of every individual from a pharmacogenetic standpoint.

A Pharmacogenetic Study of CYP2C19 in Acute Coronary Syndrome Patients of Colombian Origin Reveals New Polymorphisms Potentially Related to Clopidogrel Therapy.

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.

Update on Safety Profiles of Vitamins B1, B6, and B12: A Narrative Review.

The neurotropic B vitamins B1 (thiamine), B6 (pyridoxine), and B12 (cobalamin) are essential for proper functioning of the nervous system. Deficiencies may induce neurological disorders like peripheral neuropathy (PN) and mainly occur in vulnerable populations (eg, elderly, diabetics, alcoholics). As epidemiologic cohort studies raised safety concerns about vitamin B6/B12 intake being potentially associated with increased risks of hip fracture (HF) and lung cancer (LC), we explored these aspects and performed comprehensive literature searches. However, we suggest not to neglect actual high-risk factors (eg, smoking in LC, higher age in HF) by focusing on individual nutrients, but to examine the complex interaction of numerous factors involved in disease development. Because it warrants continued consideration, we also provide an update on neurotoxicity associated with vitamin B6. We consider that neurological side effects due to vitamin B6 intake are rare and only occur with high daily doses and/or longer treatment duration. The benefit-risk ratio of high-dose treatment with neurotropic B vitamins in indications like PN is therefore considered advantageous, particularly if dosing recommendations are followed and serum levels monitored.

Possible Genetic Determinants of Response to Phenytoin in a Group of Colombian Patients With Epilepsy.

BACKGROUND: Epilepsy is a serious health problem worldwide. Despite the introduction of new antiepileptic drugs (AEDs) almost 30% of these patients have drug-resistant forms of the disease (DRE), with a significant increase in morbi-mortality. OBJECTIVE: Our objective was to assess the impact of some genetic factors and its possible association with treatment response and adverse drug reactions (ADRs) to phenytoin in 67 adult Colombian patients with epilepsy. METHODS: We conducted an analytical, observational, prospective cohort study to screen four polymorphisms in pharmacogenes: CYP2C9*2-c.430C>T (rs1799853), CYP2C9*3-c.1075A>C (rs1057910), ABCB1-c.3435T>C (rs1045642), and SCN1A-IVS5-91G>A (rs3812718), and their association with treatment response. Patients were followed for 1 year to confirm the existence of DRE (non-response) and ADRs using an active pharmacovigilance approach, followed by a consensus in order to classify ADRs according to causality, preventability, intensity and their relation with phenytoin dose, the duration of treatment, and susceptibility factors (DoTS methodology). RESULTS: A little more than half of evaluated subjects (52.2%) were non-responding to phenytoin. Regarding the genotype-phenotype correlation there was no association between polymorphisms of SCN1A and ABCB1 and DRE (non-response) (p = 0.34), and neither with CYP2C9 polymorphisms and the occurrence of ADRs (p = 0.42). We only found an association between polymorphic alleles of CYP2C9 and vestibular-cerebellar ADRs (dizziness, ataxia, diplopia, and dysarthria) (p = 0.001). Alleles CYP2C9*2-c.430C>T and CYP2C9*3-c.1075A>C were identified as susceptibility factors to ADRs in 24% of patients. CONCLUSIONS: Decreased function alleles of CYP2C9 were highly predictive of vestibular-cerebellar ADRs to phenytoin in our study (p = 0.001). However, the genetic variants CYP2C9*2-c.430C>T, CYP2C9*3-c.1075A>C, ABCB1-c.3435T>C, and SCN1A-IVS5-91G>A, were not associated with treatment response in our study.

A Pharmacogenomic Dissection of a Rosuvastatin-Induced Rhabdomyolysis Case Evokes the Polygenic Nature of Adverse Drug Reactions.

Rosuvastatin, is a widely-used statin for the treatment of hypercholesterolemia and the prevention of cardiovascular diseases. Although rosuvastatin is well tolerated, about 3/10.000 patients can suffer severe myopathy. Rhabdomyolysis is a severe medical condition that causes injury to the skeletal muscle, electrolyte imbalances, acute renal failure and extreme creatine kinase (CK) elevation. Little is known regarding the molecular involvement of rosuvastatin-induced rhabdomyolysis (RIR). It has been demonstrated that genomic variants associated with decreased enzymatic activity of proteins are important determinants in plasmatic and skeletal muscle distribution of rosuvastatin and its toxicity. Until now, no interactions of ticagrelor, ezetimibe and rosuvastatin have been described with the consideration of pharmacogenomics predisposition. The present report involves a whole-exome sequencing (WES), in a patient affected by rosuvastatin-induced rhabdomyolysis. A pharmacogenomic dissection was performed by analyzing a comprehensive subset of candidate genes (n=160) potentially related to RIR. The genes were selected according to their implication in drug metabolism or inherited myopathies. Using an innovative approach of bioinformatics analysis, considering rare and common variants, we identified 19 genomic variations potentially related to the pharmacokinetic/pharmacodynamic modifications of rosuvastatin, ezetimibe and ticagrelor. The affected genes are involved in Phase I metabolism (CYP2C19, CYP2E1, CYP1A1, CYP2D6 and CYP2C9), Phase II metabolism (UGT2B15 and UGT2B7), influx transportation (SLCO1B3 and SLCO2B1), efflux transportation (ABCG8, ABCB11, ABCC4 and ABCB1), drug targeting (NPC1L1) and inherited myopathy etiology (OBSCN). We report three rare, potentially pathogenic molecular variants in CYP2C19, NPC1L1 and OBSCN genes. Pharmacogenetic analysis indicated that the patient was a carrier of inactivating alleles in several pharmacogenes involved in drug toxicity. The whole-exome sequencing and bioinformatics analysis presented here represents an innovative way to identify genomic variants contributing with RIR´s origin and evokes the polygenic nature of adverse drug reactions.