Pharmacogenomics of off-target adverse drug reactions

Polymorphisms of HLA genes and hypersensitivity to penicillin among patients in a Taiwanese population

Penicillin allergy is a potentially life-threatening condition that is common among patients. However, the genetic associations with penicillin allergy are not yet recognized for prevention or diagnosis, particularly in East Asian populations. We conducted a retrospective case-control study using data from the Taiwan Precision Medicine Initiative and analysing DNA samples to identify eight major MHC Class I and Class II loci. We employed imputation methods for accurate HLA typing and enrolled 17,827 individuals who received penicillin. Logistic regression analyses were utilized to explore associations between HLA genotypes, comorbidities and allergy risk, while simultaneously conducting a subgroup analysis to explore the association between HLA genotypes, comorbidities and the severity of allergic reactions. Our study assigned 496 cases to the penicillin allergy group and 4960 controls to a matched group. The risk of penicillin allergy was significantly higher with HLA-DPB1*05:01 (OR = 1.36, p = .004) and HLA-DQB1*05:01 (OR = 1.54, p = .03), with adjusted p-values of .032 and .24, respectively. Urticaria was identified as a separate risk factor (OR = 1.73, p < .001). However, neither the HLA alleles nor the comorbidities had a significant relationship with the risk of severe penicillin-induced allergy. HLA-DPB1*05:01 was found to be significantly associated with penicillin allergy reactions among the Taiwanese population.

Determination and mechanism of Xiao-Ai Jie-Du decoction against diffuse large B-cell lymphoma: In silico and In vitro studies

ETHNOPHARMACOLOGICAL RELEVANCE

Xiao-Ai Jie-Du decoction (XAJDD) has been used in clinical practice to treat diffuse large B-cell lymphoma (DLBCL); its prescriptions vary based on the pathogenesis of patients.

AIM OF THE STUDY

We aimed to determine the core formula of XAJDD and investigate its mechanism of action against DLBCL.

MATERIALS AND METHODS

Apriori data mining of 187 clinical cases (including 421 Traditional Chinese Medicines, TCMs) was conducted to retrieve the core formula of XAJDD. Comprehensive in silico modeling was used to identify potential active components and corresponding targets. The potential targets of 16 compounds were identified based on network pharmacology using in silico modeling. Thereafter, experimental determination of the active compounds and their mechanism of action in treating DLBCL was performed using different assays (including CCK-8, Annexin V-FITC/PI double-staining, Western blot, and flow cytometry assays).

RESULTS

The core formula of XAJDD included six herbs: Astragalus mongholicus Bunge (Huangqi, family: Fabaceae), Scutellaria barbata D. Don (Banzhilian, family: Lamiaceae), Prunella vulgaris L. (Xiakucao, family: Lamiaceae), Smilax glabra Roxb. (Tufuling, family Smilacaceae) and Fritillaria thunbergii Miq. (Dabei, family: Liliaceae), and Curcuma zanthorrhiza Roxb. (Ezhu, family: Zingiberaceae); Databases including 62 druggable compounds and 38 DLBCL-related structural targets were constructed; ∼0.3 million data points produced by computational modeling based on potential compounds and targets six components from XAJDD, including astibin, folic acid, baicalin, kaempferol, quercetin, and luteolin, significantly inhibited DLBCL cell proliferation, induced apoptosis, and suppressed the expression of key oncogenes.

CONCLUSION

This study provides an integrated strategy for determining the core formula of XAJDD and reveals the molecular mechanisms underlying the treatment of DLBCL, which were consistent with the principle of "monarch (Jun), minister (Chen), adjunctive (Zuo), and guide (Shi)", confirming that XAJDD may serve as a promising natural therapeutic agent against DLBCL.

Database screening as a strategy to identify endogenous candidate metabolites to probe and assess mitochondrial drug toxicity

Adverse drug reactions (ADRs) are considered an inherent risk of medication use, and some ADRs have been associated with off-target drug interactions with mitochondria. Metabolites that reflect mitochondrial function may help identify patients at risk of mitochondrial toxicity. We employed a database strategy to identify candidate mitochondrial metabolites that could be clinically useful to identify individuals at increased risk of mitochondrial-related ADRs. This led to L-carnitine being identified as the candidate mitochondrial metabolite. L-carnitine, its acetylated metabolite, acetylcarnitine and other acylcarnitines are mitochondrial biomarkers used to detect inborn errors of metabolism. We hypothesized that changes in L-carnitine disposition, induced by a "challenge test" of intravenous L-carnitine, could identify mitochondrial-related ADRs by provoking variation in L-carnitine and/or acetylcarnitine blood levels. To test this hypothesis, we induced mitochondrial drug toxicity with clofazimine (CFZ) in a mouse model. Following CFZ treatment, mice received an L-carnitine "challenge test". CFZ-induced changes in weight were consistent with previous work and reflect CFZ-induced catabolism. L-carnitine induced differences in whole blood acetylcarnitine concentrations in a manner that was dependent on CFZ treatment. This supports the usefulness of a database strategy for the discovery of candidate metabolite biomarkers of drug toxicity and substantiates the potential of the L-carnitine "challenge test" as a "probe" to identify drug-related toxicological manifestations.

HLA-targeted sequencing reveals the pathogenic role of HLA-B*15:02/HLA-B*13:01 in albendazole-induced liver failure: a case report and a review of the literature

Drug-induced liver injury (DILI) is one of the serious adverse drug reactions (ADRs), which belongs to immune-mediated adverse drug reactions (IM-ADRs). As an essential health drug, albendazole has rarely been reported to cause serious liver damage. A young man in his 30 s developed severe jaundice, abnormal transaminases, and poor blood coagulation mechanism after taking albendazole, and eventually developed into severe liver failure. The patient was found heterozygous of HLA-B*15:02 and HLA-B*13:01 through HLA-targeted sequencing, which may have a pathogenic role in the disease. This case report summarizes his presentation, treatment, and prognosis. A useful summary of the diagnosis and associated genetic variant information is provided.

The tale of antibiotics beyond antimicrobials: Expanding horizons

Antibiotics had proved to be a godsend for mankind since their discovery. They were once the magical solution to the vexing problem of infection-related deaths. German scientist Paul Ehrlich had termed salvarsan as the silver bullet to treatsyphilis.As time passed, the magic of newly discovered silver bullets got tarnished with raging antibiotic resistance among bacteria and associated side-effects. Still, antibiotics remain the primary line of treatment for bacterial infections. Our understanding of their chemical and biological activities has increased immensely with advancement in the research field. Non-antibacterial effects of antibiotics are studied extensively to optimise their safer, broad-range use. These non-antibacterial effects could be both useful and harmful to us. Various researchers across the globe including our lab are studying the direct/indirect effects and molecular mechanisms behind these non-antibacterial effects of antibiotics. So, it is interesting for us to sum up the available literature. In this review, we have briefed the possible reason behind the non-antibacterial effects of antibiotics, owing to the endosymbiotic origin of host mitochondria. We further discuss the physiological and immunomodulatory effects of antibiotics. We then extend the review to discuss molecular mechanisms behind the plausible use of antibiotics as anticancer agents.

Large-scale prediction of adverse drug reactions-related proteins with network embedding

MOTIVATION

Adverse drug reactions (ADRs) are a major issue in drug development and clinical pharmacology. As most ADRs are caused by unintended activity at off-targets of drugs, the identification of drug targets responsible for ADRs becomes a key process for resolving ADRs. Recently, with the increase in the number of ADR-related data sources, several computational methodologies have been proposed to analyze ADR-protein relations. However, the identification of ADR-related proteins on a large scale with high reliability remains an important challenge.

RESULTS

In this article, we suggest a computational approach, Large-scale ADR-related Proteins Identification with Network Embedding (LAPINE). LAPINE combines a novel concept called single-target compound with a network embedding technique to enable large-scale prediction of ADR-related proteins for any proteins in the protein-protein interaction network. Analysis of benchmark datasets confirms the need to expand the scope of potential ADR-related proteins to be analyzed, as well as LAPINE's capability for high recovery of known ADR-related proteins. Moreover, LAPINE provides more reliable predictions for ADR-related proteins (Value-added positive predictive value = 0.12), compared to a previously proposed method (P < 0.001). Furthermore, two case studies show that most predictive proteins related to ADRs in LAPINE are supported by literature evidence. Overall, LAPINE can provide reliable insights into the relationship between ADRs and proteomes to understand the mechanism of ADRs leading to their prevention.

AVAILABILITY AND IMPLEMENTATION

The source code is available at GitHub (https://github.com/rupinas/LAPINE) and Figshare (https://figshare.com/articles/software/LAPINE/21750245) to facilitate its use.

SUPPLEMENTARY INFORMATION

Supplementary data are available at Bioinformatics online.

Suspected adverse drug reactions of the type 2 antidiabetic drug class dipeptidyl-peptidase IV inhibitors (DPP4i): Can polypharmacology help explain?

To interpret the relationship between the polypharmacology of dipeptidyl-peptidase IV inhibitors (DPP4i) and their suspected adverse drug reaction (ADR) profiles using a national registry. A retrospective investigation into the suspected ADR profile of four licensed DPP4i in the United Kingdom using the National MHRA Yellow Card Scheme and OpenPrescribing databases. Experimental data from the ChEMBL database alongside physiochemical (PC) and pharmacokinetic (PK) profiles were extracted and interpreted. DPP4i show limited polypharmacology alongside low suspected ADR rates. We found a minimal statistical difference between the unique ADR profiles ascribed to the DPP4i except for total ADRs (χ2 ; p < .05). Alogliptin consistently showed the highest suspected ADR rate per 1 000 000 items prescribed. Saxagliptin showed the lowest suspected ADR rate across all organ classes but did not reach statistical difference (χ2 ; p > .05). We confirmed the Phase III clinical trial data that showed gastrointestinal and skin reactions are the most reported ADRs across the DPP4i class and postulated underlying mechanisms for this based on possible drug interactions. The main pharmacological mechanism behind the ADRs is attributed to interactions with DPP4 activity and/or structure homolog (DASH) proteins which augment the immune-inflammatory modulation of DPP4.

Marine Natural Products in Clinical Use

Marine natural products are potent and promising sources of drugs among other natural products of plant, animal, and microbial origin. To date, 20 drugs from marine sources are in clinical use. Most approved marine compounds are antineoplastic, but some are also used for chronic neuropathic pain, for heparin overdosage, as haptens and vaccine carriers, and for omega-3 fatty-acid supplementation in the diet. Marine drugs have diverse structural characteristics and mechanisms of action. A considerable increase in the number of marine drugs approved for clinical use has occurred in the past few decades, which may be attributed to increasing research on marine compounds in laboratories across the world. In the present manuscript, we comprehensively studied all marine drugs that have been successfully used in the clinic. Researchers and clinicians are hopeful to discover many more drugs, as a large number of marine natural compounds are being investigated in preclinical and clinical studies.

Pathology of T-cell-mediated drug hypersensitivity reactions and impact of tolerance mechanisms on patient susceptibility

PURPOSE OF REVIEW

T-cell-mediated drug hypersensitivity is responsible for significant morbidity and mortality, and represents a substantial clinical concern. The purpose of this article is to focus on T-cell reactions and discuss recent advances in disease pathogenesis by exploring the impact of tolerance mechanisms in determining susceptibility in genetically predisposed patients.

RECENT FINDINGS

Certain drugs preferentially activate pathogenic T cells that have defined pathways of effector function. Thus, a critical question is what extenuating factors influence the direction of immune activation. A large effort has been given towards identifying phenotypic (e.g., infection) or genotypic (e.g., human leukocyte antigen) associations which predispose individuals to drug hypersensitivity. However, many individuals expressing known risk factors safely tolerate drug administration. Thus, mechanistic insight is needed to determine what confers this tolerance. Herein, we discuss recent clinical/mechanistic findings which indicate that the direction in which the immune system is driven relies upon a complex interplay between co-stimulatory/co-regulatory pathways which themselves depend upon environmental inputs from the innate immune system.

SUMMARY

It is becoming increasingly apparent that tolerance mechanisms impact on susceptibility to drug hypersensitivity. As the field moves forward it will be interesting to discover whether active tolerance is the primary response to drug exposure, with genetic factors such as HLA acting as a sliding scale, influencing the degree of regulation required to prevent clinical reactions in patients.

Systematic analysis of the potential off-target activities of osimertinib by computational target fishing

Osimertinib is a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor used to treat non-small cell lung cancer. However, its off-targets are obscure, and systematic analysis of off-target activities remains to be performed. Here, we identified the off-targets of osimertinib using PharmMapper and DRAR-CPI and analyzed the intersected targets using the GeneMANIA and DAVID servers. A drug-target-pathway network was constructed to visualize the associations. The results showed that osimertinib is associated with 31 off-targets, 40 Kyoto Encyclopedia of Genes and Genomes pathways, and 9 diseases. Network analysis revealed that the targets were involved in cancer and other physiological processes. In addition to EGFR, molecular docking analysis showed that seven proteins, namely Janus kinase 3, peroxisome proliferator-activated receptor alpha, renin, mitogen-activated protein kinases, lymphocyte-specific protein tyrosine kinase, cell division protein kinase 2 and proto-oncogene tyrosine-protein kinase Src, could also be potential targets of osimertinib. In conclusion, osimertinib is predicted to target multiple proteins and pathways, resulting in the formation of an action network via which it exerts systematic pharmacological effects.

Genophenotypic Factors and Pharmacogenomics in Adverse Drug Reactions

Adverse drug reactions (ADRs) rank as one of the top 10 leading causes of death and illness in developed countries. ADRs show differential features depending upon genotype, age, sex, race, pathology, drug category, route of administration, and drug–drug interactions. Pharmacogenomics (PGx) provides the physician effective clues for optimizing drug efficacy and safety in major problems of health such as cardiovascular disease and associated disorders, cancer and brain disorders. Important aspects to be considered are also the impact of immunopharmacogenomics in cutaneous ADRs as well as the influence of genomic factors associated with COVID-19 and vaccination strategies. Major limitations for the routine use of PGx procedures for ADRs prevention are the lack of education and training in physicians and pharmacists, poor characterization of drug-related PGx, unspecific biomarkers of drug efficacy and toxicity, cost-effectiveness, administrative problems in health organizations, and insufficient regulation for the generalized use of PGx in the clinical setting. The implementation of PGx requires: (i) education of physicians and all other parties involved in the use and benefits of PGx; (ii) prospective studies to demonstrate the benefits of PGx genotyping; (iii) standardization of PGx procedures and development of clinical guidelines; (iv) NGS and microarrays to cover genes with high PGx potential; and (v) new regulations for PGx-related drug development and PGx drug labelling.

The challenge of detecting adverse events in adults with autism spectrum disorder who have intellectual disability

Adults with autism spectrum disorder (ASD) and associated intellectual disability (ID) take a high number of different psychotropic drugs simultaneously. Nowadays, little is known about this multidrug pattern efficacy and safety. The present study has endeavored to fill this gap creating a local pharmacovigilance system. A 36-month, retrospective and prospective, observational, and multicenter pharmacovigilance study was carried out in adults with ASD and ID (n = 83). Information regarding ongoing medications (polypharmacy: taking simultaneously >4 drugs; safety profile: adverse events' number, adverse drug reactions' number, and affected system; and observed-to-expected [O/E] ratio using the summary of product characteristics), and current diagnoses were recorded. A median of four ongoing medications per participant was registered, half of the sample was under polypharmacy regimen. Regarding all ongoing medications, 50% were antipsychotic drugs, and 47% of participants had >1 antipsychotic prescribed. In contrast, only 64 adverse events were identified from electronic health records, mostly due to risperidone. Half of them were related either to nervous or metabolic systems, and almost a third were not previously described in the corresponding drug summary of products characteristics. Extrapyramidalism, gynecomastia, hypercholesterolemia, and urinary retention were some AEs that occurred more frequently than expected (O/E ratio > 6 times) according to our data. The highest O/E ratio scores (>120 times) were for hypercholesterolemia and rhabdomyolysis caused by valproic acid. According to the number of adverse events and adverse drug reactions reported in electronic health records locally and nationally by clinicians, we need to increase awareness about medications safety. LAY SUMMARY: A 36-month study in adults with autism, ID, and polypharmacy (>4 drugs) was done to investigate drug safety on everyone. A median of four medications per person was registered, half were antipsychotic drugs, and 47% of participants had >1 antipsychotic medication simultaneously. Only 64 adverse events were identified from electronic health records, mostly due to risperidone. Half of them were related to nervous or metabolic systems and a third were not previously described in the drug information sheet.

Polypharmacology of clinical sodium glucose co-transport protein 2 inhibitors and relationship to suspected adverse drug reactions

Sodium glucose co-transporter 2 inhibitors (SGLT2i) are a promising second-line treatment strategy for type 2 diabetes mellitus (T2DM) with a developing landscape of both beneficial cardio- and nephroprotective properties and emerging adverse drug reactions (ADRs) including diabetic ketoacidosis (DKA), genetic mycotic infections, and amputations among others. A national register study (MHRA Yellow Card, UK) was used to quantify the SGLT2i's suspected ADRs relative to their Rx rate (OpenPrescribing, UK). The polypharmacology profiles of SGLT2i were data-mined (ChEMBL) for the first time. The ADR reports (n = 3629) and prescribing numbers (Rx n = 5,813,325) for each SGLT2i in the United Kingdom (from launch date to the beginning December 2019) were determined. Empagliflozin possesses the most selective SGLT2/SGLT1 inhibition profile at ~2500-fold, ~10-fold more selective than cangliflozin (~260-fold). Canagliflozin was found to also inhibit CYP at clinically achievable concentrations. We find that for overall ADR rates, empagliflozin versus dapagliflozin and empagliflozin versus canagliflozin are statistically significant (χ2 , p < .05), while dapagliflozin versus canagliflozin is not. In terms of overall ADRs, there is a greater relative rate for canagliflozin > dapagliflozin > empagliflozin. For fatalities, there is a greater relative rate for dapagliflozin > canagliflozin > empagliflozin. An organ classification that resulted in a statistically significant difference between SGLT2i was suspected infection/infestation ADRs between empagliflozin and dapagliflozin. Our findings at this stage of SGLT2i usage in the United Kingdom suggest that empagliflozin, the most selective SGLT2i, had the lowest suspected ADR incident rate (relative to prescribing) and in all reported classes of ADRs identified including infections, amputations, and DKA.

Prevention of Drug Hypersensitivity Reactions: Prescreening and Premedication

Drug hypersensitivity reactions (DHR) are heterogeneous in their pathomechanisms, clinical presentation, severity, and outcomes. Novel DHR mechanisms, phenotypes, and endotypes have been described. The key to prevention from further exposure to the culprit drugs involves correct identification of the putative drug through a combination of in vitro and/or in vivo tests, accurate drug allergy labeling and reporting, and electronic decision support systems within electronic medical records to prevent future accidental prescribing. Prescreening and premedication, the focus of this review, may be a useful adjunct to preventive measures in certain situations. After an index immediate drug hypersensitivity reaction, prescreening may be useful in perioperative anaphylaxis, and iodinated (ICM) and gadolinium-based contrast media (GCM) where the culprit and potential alternative agents are skin tested. In certain nonimmediate DHR, pharmacogenomic prescreening may be used before prescribing high-risk drugs (eg, carbamazepine and allopurinol) where specific human-leukocyte antigen genotypes are associated with severe cutaneous adverse reactions. Premedication with antihistamine and systemic corticosteroids is another therapeutic strategy to prevent infusion reactions for certain biologicals and chemotherapeutic agents, in cases of perioperative anaphylaxis, ICM and GCM DHR, and clonal mast cell disorders. Rapid drug desensitization may also be used to induce temporary tolerance in situations where there are limited alternative drugs.

Molecular fingerprinting by single cell clone analysis in adverse drug reaction (ADR) assessment

Causality assessment for idiosyncratic ADRs mainly relies on epidemiology, signal detection and less often on proven or plausible mechanistic evidence of the drug at a cellular or organ level. Distinct clones of cells can exist within organs of individual patients, some conferring susceptibility to well recognised adverse drug reactions (ADRs). Recent advances in molecular biology has allowed the development of single cell clonal techniques, including single cell RNA sequencing (scRNA-seq) to molecularly fingerprint ADRs and distinguish between distinct clones of cells within organs in individuals, which may confer differing susceptibilities to ADRs. ScRNA-seq permits molecular fingerprinting of some serious ADRs, mainly in the skin, through identification of directly expressed genes (DEG) of interest within specific clones. Overexpressed DEGs provides an opportunity for targeted treatment strategies to be developed. scRNA-seq could be applied to a number of other ADRs involving tissues that can be biopsied/sampled (including skin, liver, kidney, blood, stem cells) as well as providing a molecular basis for rapid screening of potential therapeutic candidates, which may not otherwise be predictable from class of toxicity/organ involvement. . A framework for putative assessment for ADRs using scRNA-seq is proposed as well as speculating on potential regulatory implications for pharmacovigilance and drug development. Molecular fingerprinting of ADRs using scRNA-seq may allow better targeting for enhanced pharmacovigilance and risk minimisation measures for medicines with appropriate benefit risk profiles, although cost-effectiveness and other factors, such as frequency/severity of individual ADRs and population differences will still be relevant.

Tackling the Patient with Multiple Drug "Allergies": Multiple Drug Intolerance Syndrome

As populations age, the prevalence of reported drug "allergy" increases, often leading to suboptimal care and increased morbidity because of unnecessary avoidance of safe and effective medications. Evaluation by a drug allergy specialist is often warranted when a patient has more than 2 unrelated drug "allergies" listed in the medical record. In this commentary, we clarify and propose standard terminology to use when evaluating patients with multiple drug allergy labels including and more specifically when diagnosing multiple drug intolerance syndrome and the much rarer multiple drug hypersensitivity syndrome. We review epidemiology and key features of multiple drug intolerance syndrome and multiple drug hypersensitivity syndrome. We summarize the methodologic and practical diagnostic workup and management of individuals with MDIS to assist with the accurate delabeling of drug "allergies" in the electronic health record.

Systematic mapping of cancer cell target dependencies using high-throughput drug screening in triple-negative breast cancer

While high-throughput drug screening offers possibilities to profile phenotypic responses of hundreds of compounds, elucidation of the cell context-specific mechanisms of drug action requires additional analyses. To that end, we developed a computational target deconvolution pipeline that identifies the key target dependencies based on collective drug response patterns in each cell line separately. The pipeline combines quantitative drug-cell line responses with drug-target interaction networks among both intended on- and potent off-targets to identify pharmaceutically actionable and selective therapeutic targets. To demonstrate its performance, the target deconvolution pipeline was applied to 310 small molecules tested on 20 genetically and phenotypically heterogeneous triple-negative breast cancer (TNBC) cell lines to identify cell line-specific target mechanisms in terms of cytotoxic and cytostatic drug target vulnerabilities. The functional essentiality of each protein target was quantified with a target addiction score (TAS), as a measure of dependency of the cell line on the therapeutic target. The target dependency profiling was shown to capture inhibitory information that is complementary to that obtained from the structure or sensitivity of the drugs. Comparison of the TAS profiles and gene essentiality scores from CRISPR-Cas9 knockout screens revealed that certain proteins with low gene essentiality showed high target addictions, suggesting that they might be functioning as protein groups, and therefore be resistant to single gene knock-out. The comparative analysis discovered protein groups of potential multi-target synthetic lethal interactions, for instance, among histone deacetylases (HDACs). Our integrated approach also recovered a number of well-established TNBC cell line-specific drivers and known TNBC therapeutic targets, such as HDACs and cyclin-dependent kinases (CDKs). The present work provides novel insights into druggable vulnerabilities for TNBC, and opportunities to identify multi-target synthetic lethal interactions for further studies.

CETSA MS Profiling for a Comparative Assessment of FDA-Approved Antivirals Repurposed for COVID-19 Therapy Identifies TRIP13 as a Remdesivir Off-Target

The reuse of preexisting small molecules for a novel emerging disease threat is a rapid measure to discover unknown applications for previously validated therapies. A pertinent and recent example where such a strategy could be employed is in the fight against coronavirus disease 2019 (COVID-19). Therapies designed or discovered to target viral proteins also have off-target effects on the host proteome when employed in a complex physiological environment. This study aims to assess these host cell targets for a panel of FDA-approved antiviral compounds including remdesivir, using the cellular thermal shift assay (CETSA) coupled with mass spectrometry (CETSA MS) in noninfected cells. CETSA MS is a powerful method to delineate direct and indirect interactions between small molecules and protein targets in intact cells. Biologically active compounds can induce changes in thermal stability, in their primary binding partners, and in proteins that in turn interact with the direct targets. Such engagement of host targets by antiviral drugs may contribute to the clinical effect against the virus but can also constitute a liability. We present here a comparative study of CETSA molecular target engagement fingerprints of antiviral drugs to better understand the link between off-targets and efficacy.

Relevance of physicochemical properties and functional pharmacology data to predict the clinical safety profile of direct oral anticoagulants

Direct oral anticoagulants (DOACs) have rapidly become the drug class of choice for anticoagulation therapy in secondary care. It is known that gastrointestinal hemorrhage are potential side effects of the DOAC drug class. In this study we have investigated the relevance of molecular structure and on/off-target pharmacology as a predictor of adverse drug reactions (ADRs) for the DOAC drug class. Use of the Reaxys MedChem module allowed for data mining of all possible reported off-target effects of the DOAC class members. For the first time, the MHRA Yellow card database in combination with prescribing rates in the United Kingdom (data for n = 30 566 936 DOAC Rx (up to 2017) and ADR data n = 22 275 (up to 2018)) were used for our data comparison of DOACs. From the underlying reported data, we were able to rank the DOACs in terms of the likely adverse events we would expect to observe. We identified potential risks of ADRs based on the DOACs pharmacology including the expected GI hemorrhage, but also the unexpected risk of stroke, pulmonary embolism and kidney injury. Statistically significant (P < .001) differences were found between all DOACs and their total number of ADRs. Although the risks are small, strong statistical correlation between observed pharmacology and national ADR data is observed in three out of the five areas of concern.

Immune-mediated adverse reactions to vaccines

Vaccination continues to be the single most important and successful public health intervention, due to its prevention of morbidity and mortality from prevalent infectious diseases. Severe immunologically mediated reactions are rare and less common with the vaccine than the true infection. However, these events can cause public fearfulness and loss of confidence in the safety of vaccination. In this paper, we perform a systematic literature search and narrative review of immune-mediated vaccine adverse events and their known and proposed mechanisms, and outline directions for future research. Improving our knowledge base of severe immunologically mediated vaccine reactions and their management drives better vaccine safety and efficacy outcomes.

Optimizing drug selection in psychopharmacology based on 40 significant CYP2C19- and CYP2D6-biased adverse drug reactions of selective serotonin reuptake inhibitors

Background

Selective serotonin reuptake inhibitors (SSRIs) are among the most widely prescribed class of drugs in the practice of psychiatry. Cytochrome P450 (CYP) 2C19 and CYP2D6 are established as clinically relevant drug metabolizing enzymes (DMEs) that influence the pharmacokinetics of SSRIs and may either be grouped as being primarily metabolized by CYP2C19 or CYP2D6. The aim of this study is to test the hypothesis that the primary drug metabolizing pathway for SSRI antidepressants are associated with adverse drug reactions (ADRs) related to physiological modulation of organs with the highest gene tissue expression.

Methods

Post-marketing ADR cases were obtained from the United States Food and Drug Administration’s Adverse Events Reporting System from each of the four quarters for the years 2016 and 2017. Cases were grouped based on one of two primary pharmacokinetic pharmacogenomic pathway biomarkers CYP2C19 and CYP2D6. Citalopram, escitalopram, and sertraline were grouped as CYP2C19 substrates and fluvoxamine, fluoxetine, and paroxetine as CYP2D6 substrates. Logistic regression was computed for the reported SSRI ADRs associated with one of two aforementioned DMEs. All data homogenization and computations were performed in R for statistical programming.

Results

The most commonly reported ADR among the SSRIs was anxiety (n = 3,332). The top two ADRs associated with SSRIs metabolized by CYP2D6 are: nightmare (n = 983) reporting odds-ratio (OR) = 4.37 (95% confidence interval (CI) [3.67–5.20]) and panic attack (n = 1,243) OR = 2.43 (95% CI [2.11–2.79]). Contrastingly, the top two ADRs for CYP2C19 metabolized SSRIs are: electrocardiogram QT prolonged (n = 351) OR = 0.18 (95% CI [0.13–0.24]) and small for dates baby (n = 306) OR = 0.19 (95% CI [0.14–0.26]). The study tested and produced 40 statistically significant CYP2C19- and CYP2D6-biased ADRs. In overall context, the results suggest that CYPC19 SSRI substrates are associated with ADRs related to modulation of the autonomic nervous system, seizure, pain, erectile-dysfunction, and absorption. Contrastingly, CYP2D6 SSRI substrates are associated with ADRs related to nightmares, withdrawal syndrome, and de-realization of cognitive processes. The results of this study may aid as guidance to optimize drug selection in psychopharmacology.

HLA-B*35:01 Allele Is a Potential Biomarker for Predicting Polygonum multiflorum-Induced Liver Injury in Humans

Polygonum multiflorum (PM) is a well-known Chinese herbal medicine that has been reported to induce inflammation-associated idiosyncratic liver injury. This study aimed to identify the genetic basis of susceptibility to PM-drug-induced liver injury (PM-DILI) and to develop biological markers for predicting the risk of PM-DILI in humans. The major histocompatibility complex (MHC) regions of 11 patients with PM-DILI were sequenced, and all human leukocyte antigen (HLA)-type frequencies were compared to the Han-MHC database. An independent replication study that included 15 patients with PM-DILI, 33 patients with other DILI, and 99 population controls was performed to validate the candidate allele by HLA-B PCR sequence-based typing. A prospective cohort study that included 72 outpatients receiving PM for 4 weeks was designed to determine the influence of the risk allele on PM-DILI. In the pilot study, the frequency of HLA-B*35:01 was 45.4% in PM-DILI patients compared with 2.7% in the Han Chinese population (odds ratio [OR], 30.4; 95% confidence interval [CI], 11.7-77.8; P = 1.9 × 10^-10 ). In the independent replication study and combined analyses, a logistic regression model confirmed that HLA-B*35:01 is a high-risk allele of PM-DILI (PM-DILI versus other DILI, OR, 86.5; 95% CI, 14.2-527.8, P = 1.0 × 10^-6 ; and PM-DILI versus population controls, OR, 143.9; 95% CI, 30.1-687.5, P = 4.8 × 10^-10 ). In the prospective cohort study, an asymptomatic increase in transaminase levels was diagnosed in 6 patients, representing a significantly higher incidence (relative risk, 8.0; 95% CI, 1.9-33.2; P < 0.02) in the HLA-B*35:01 carriers (37.5%) than in the noncarriers (4.7%). Conclusion: The HLA-B*35:01 allele is a genetic risk factor for PM-DILI and a potential biomarker for predicting PM-DILI in humans.

Antibiotic allergy

Antibiotics are the commonest cause of life-threatening immune-mediated drug reactions that are considered off-target, including anaphylaxis, and organ-specific and severe cutaneous adverse reactions. However, many antibiotic reactions documented as allergies were unknown or not remembered by the patient, cutaneous reactions unrelated to drug hypersensitivity, drug-infection interactions, or drug intolerances. Although such reactions pose negligible risk to patients, they currently represent a global threat to public health. Antibiotic allergy labels result in displacement of first-line therapies for antibiotic prophylaxis and treatment. A penicillin allergy label, in particular, is associated with increased use of broad-spectrum and non-β-lactam antibiotics, which results in increased adverse events and antibiotic resistance. Most patients labelled as allergic to penicillins are not allergic when appropriately stratified for risk, tested, and re-challenged. Given the public health importance of penicillin allergy, this Review provides a global update on antibiotic allergy epidemiology, classification, mechanisms, and management.

Cephalosporin Allergy: Current Understanding and Future Challenges

Cephalosporins are commonly used antibiotics both in hospitalized patients and in outpatients. Hypersensitivity reactions to cephalosporins are becoming increasingly common with a wide range of immunopathologic mechanisms. Cephalosporins are one of the leading causes for perioperative anaphylaxis and severe cutaneous adverse reactions. Patients allergic to cephalosporins tend to tolerate cephalosporins with disparate R1 side chains but may react to other beta-lactams with common R1 side chains. Skin testing for cephalosporins has not been well validated but appears to have a good negative predictive value for cephalosporins with disparate R1 side chains. In vitro tests including basophil activation tests have lower sensitivity when compared with skin testing. Rapid drug desensitization procedures are safe and effective and have been used successfully for immediate and some nonimmediate cephalosporin reactions. Many gaps in knowledge still exist regarding cephalosporin hypersensitivity.

Controversies in drug allergy: Testing for delayed reactions

Controversies exist with regard to in vivo approaches to delayed immunologically mediated adverse drug reactions, such as exanthem (maculopapular eruption), drug reaction with eosinophilia and systemic symptoms, acute generalized exanthematous pustulosis, Stevens-Johnson syndrome/toxic epidermal necrolysis, and fixed drug eruptions. In particular, widespread differences exist between regions and practice on the availability and use of intradermal and patch testing, the standard drug concentrations used, the use of additional drugs in intradermal and patch testing to help determine cross-reactivity, the timing of testing in relation to the occurrence of the adverse drug reaction, the use of testing in specific phenotypes, and the use of oral challenge in conjunction with delayed intradermal and patch testing to ascertain drug tolerance. It was noted that there have been advances in the science of delayed T cell-mediated reactions that have shed light on immunopathogenesis and provided a mechanism of preprescription screening in the case of HLA-B*57:01 and abacavir hypersensitivity and HLA-B*15:02 and carbamazepine Stevens-Johnson syndrome/toxic epidermal necrolysis in Southeast Asian subjects. Future directions should include the collaboration of large international networks to develop and standardize in vivo diagnostic approaches, such as skin testing and patch testing, combined with ex vivo and in vitro laboratory approaches.

Microbes, not humans: exploring the molecular basis of Pseudouridimycin selectivity towards bacterial and not human RNA polymerase

OBJECTIVE

Bacterial RNA polymerase (bRNAP) represent a crucial target for curtailing microbial activity but its structural and sequence similarities with human RNA polymerase II (hRNAPII) makes it difficult to target. Recently, Pseudouridimycin (PUM), a novel nucleoside analogue was reported to selectively inhibit bRNAP and not hRNAP. Till date, underlying mechanisms of PUM selectivity remains unresolved, hence the aim of this study.

RESULTS

Using sequence alignment method, we observed that the β' of bRNAP and the RPB1 subunits of hRNAPII were highly conserved while the β and RPB2 subunits of both proteins were also characterized by high sequence variations. Furthermore, the impact of these variations on the differential binding of PUM was evaluated using MMPB/SA binding free energy and per-residue decomposition analysis. These revealed that PUM binds better to bRNAP than hRNAP with prominent bRNAP active site residues that contributed the most to PUM binding and stabilization lacking in hRNAPII active site due to positional substitution. Also, the binding of PUM to hRNAP was characterized by the formation of unfavorable interactions. In addition, PUM assumed favorable orientations that possibly enhanced its mobility towards the hydrophobic core region of bRNAP. On the contrary, unfavorable intramolecular interactions characterize PUM orientations at the binding site of hRNAPII, which could restrict its movement due to electrostatic repulsions.

CONCLUSION

These findings would enhance the design of potent and selective drugs for broad-spectrum antimicrobial activity.

Antibiotic Allergy in Pediatrics

The overlabeling of pediatric antibiotic allergy represents a huge burden in society. Given that up to 10% of the US population is labeled as penicillin allergic, it can be estimated that at least 5 million children in this country are labeled with penicillin allergy. We now understand that most of the cutaneous symptoms that are interpreted as drug allergy are likely viral induced or due to a drug-virus interaction, and they usually do not represent a long-lasting, drug-specific, adaptive immune response to the antibiotic that a child received. Because most antibiotic allergy labels acquired in childhood are carried into adulthood, the overlabeling of antibiotic allergy is a liability that leads to unnecessary long-term health care risks, costs, and antibiotic resistance. Fortunately, awareness of this growing burden is increasing and leading to more emphasis on antibiotic allergy delabeling strategies in the adult population. There is growing literature that is used to support the safe and efficacious use of tools such as skin testing and drug challenge to evaluate and manage children with antibiotic allergy labels. In addition, there is an increasing understanding of antibiotic reactivity within classes and side-chain reactions. In summary, a better overall understanding of the current tools available for the diagnosis and management of adverse drug reactions is likely to change how pediatric primary care providers evaluate and treat patients with such diagnoses and prevent the unnecessary avoidance of antibiotics, particularly penicillins.

Proton Pump Inhibitors Increase the Susceptibility of Mice to Oral Infection with Enteropathogenic Bacteria

BACKGROUND AND AIMS

Proton pump inhibitors (PPIs) are among the most frequently prescribed medications. Side effects including an increased risk of intestinal infections have been reported. It is assumed that PPIs can increase susceptibility to enteropathogens; however, the underlying mechanisms are unknown. Here in this study, we explored whether Lansoprazole (Laz), one of the PPIs, increases the susceptibility to enteropathogens, and further investigated the mechanism of it.

METHODS

Mice were administered Laz intraperitoneally once daily and orally infected with Citrobacter rodentium (C. rodentium). The establishment of intestinal infection was assessed by histology and inflammatory cytokine expression levels measured by quantitative PCR. To test whether Laz changes the intestinal environment to influence the susceptibility, intestinal pH, microbiota, metabolites and immune cell distributions were evaluated via pH measurement, 16S rRNA gene sequencing, metabolome, and flow cytometry analyses after Laz administration.

RESULTS

Colitis was induced with less C. rodentium in Laz-treated mice as compared with the controls. We found that increased numbers of C. rodentium could reach the cecum following Laz administration. Laz increased pH in the stomach but not in the intestines. It induced dysbiosis and changed the metabolite content of the small intestine. However, these changes did not lead to alterations of immune cell distribution.

CONCLUSIONS

Laz raised susceptibility to C. rodentium as increased numbers of the pathogen reach the site of infection. Our results suggest that it was due to increased stomach pH which allowed more peroral enteropathogens to pass the stomach, but not because of changes of intestinal environment.

NEW STRATEGIES TO PREDICT AND PREVENT SERIOUS IMMUNOLOGICALLY MEDIATED ADVERSE DRUG REACTIONS

Preventive efforts for serious immunologically mediated adverse drug reactions (IM-ADRs) have been fueled by discovery of strong class I human leukocyte antigen (HLA) associations; however, the low positive predictive value of HLA for IM-ADRs has limited translation. Studies were undertaken to explain why most patients carrying an HLA risk allele do not develop IM-ADR on exposure to the risk drug. Tissue-specific approaches defined the T-cell receptor (TCR) repertoire and phenotype of the pathogenic T cells found in the skin and blister fluid of IM-ADRs. Dominant CD8+ T cell clonotypes representing >50% of total TCRαβ sequences among CD8+ CD137+ T cells were identified in tissue to identify the pathogenic activated T cells. Identification of the specific molecular and cellular signatures of the antigen-driven pathogenic T cells will facilitate more specific mechanisms to determine the small percentage of individuals carrying an HLA risk allele who are likely to develop an IM-ADR before drug exposure.

Drug Hypersensitivity and Anaphylaxis in Cancer and Chronic Inflammatory Diseases: The Role of Desensitizations

Drug allergy is a rising problem in the twenty-first century which affects all populations and races, children, and adults, and for which the recognition, diagnosis, management, and treatment is still not well standardized. Classical and new chemotherapy drugs, monoclonal antibodies (MoAbs), and small molecules to treat cancer and chronic inflammatory diseases are aimed at improving quality of life and life expectancy of patients, but an increasing number of reactions including anaphylaxis precludes their use in targeted populations. Women are more affected by drug allergy and up to 27% of women with ovarian and breast cancer develop carboplatin allergy after multiple cycles of treatment. Carriers of BRCA genes develop drug allergy after fewer exposures and can present with severe reactions, including anaphylaxis. Atopic patients are at increased risk for chemotherapy and MoAbs drug allergy and the current patterns of treatment with recurrent and intermittent drug exposures may favor the development of drug allergies. To overcome drug allergy, desensitization has been developed, a novel approach which provides a unique opportunity to protect against anaphylaxis and to improve clinical outcomes. There is evidence that inhibitory mechanisms blocking IgE/antigen mast cell activation are active during desensitization, enhancing safety. Whether desensitization modulates drug allergic and anaphylactic responses facilitating tolerance is currently being investigated. This review provides insight into the current knowledge of drug allergy and anaphylaxis to cancer and chronic inflammatory diseases drugs, the mechanisms of drug desensitization and its applications to personalized medicine.

Pharmacogenomics of off-target adverse drug reactions

Off-target adverse drug reactions (ADRs) are associated with significant morbidity and costs to the healthcare system, and their occurrence is not predictable based on the known pharmacological action of the drug's therapeutic effect. Off-target ADRs may or may not be associated with immunological memory, although they can manifest with a variety of shared clinical features, including maculopapular exanthema, severe cutaneous adverse reactions (SCARs), angioedema, pruritus and bronchospasm. Discovery of specific genes associated with a particular ADR phenotype is a foundational component of clinical translation into screening programmes for their prevention. In this review, genetic associations of off-target drug-induced ADRs that have a clinical phenotype suggestive of an immunologically mediated process and their mechanisms are highlighted. A significant proportion of these reactions lack immunological memory and current data are informative for these ADRs with regard to disease pathophysiology, therapeutic targets and biomarkers which may identify patients at greatest risk. Although many serious delayed immune-mediated (IM)-ADRs show strong human leukocyte antigen associations, only a small subset have successfully been implemented in screening programmes. More recently, other factors, such as drug metabolism, have been shown to contribute to the risk of the IM-ADR. In the future, pharmacogenomic targets and an understanding of how they interact with drugs to cause ADRs will be applied to drug design and preclinical testing, and this will allow selection of optimal therapy to improve patient safety.