Drug-Induced Skin Adverse Reactions: The Role of Pharmacogenomics in Their Prevention

ALDRESS: A Retrospective Pilot Study to Develop a Pharmacological Causality Algorithm for Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)

Background: The drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome represents a severe form of drug hypersensitivity reaction characterized by significant morbidity, mortality, and long-term sequelae, coupled with limited therapeutic avenues. Accurate identification of the causative drug(s) is paramount for acute management, exploration of safe therapeutic alternatives, and prevention of future occurrences. However, the absence of a standardized diagnostic test and a specific causality algorithm tailored to DRESS poses a significant challenge in its clinical management. Methods: We conducted a retrospective case-control study involving 37 DRESS patients to validate a novel causality algorithm, the ALDRESS, designed explicitly for this syndrome, comparing it against the current standard algorithm, SEFV. Results: The ALDRESS algorithm showcased superior performance, exhibiting an 85.7% sensitivity and 93% specificity with comparable negative predictive values (80.6% vs. 97%). Notably, the ALDRESS algorithm yielded a substantially higher positive predictive value (75%) compared to SEFV (51.40%), achieving an overall accuracy rate of 92%. Conclusions: Our findings underscore the efficacy of the ALDRESS algorithm in accurately attributing causality to drugs implicated in DRESS syndrome. However, further validation studies involving larger, diverse cohorts are warranted to consolidate its clinical utility and broaden its applicability. This study lays the groundwork for a refined causality assessment tool, promising advancements in the diagnosis and management of DRESS syndrome.

Pharmacogenomics in clinical trials: an overview

With the trend towards promoting personalised medicine (PM), the application of pharmacogenetics and pharmacogenomics (PGx) is of growing importance. For the purposes of clinical trials, the inclusion of PGx is an additional tool that should be considered for improving our knowledge about the effectiveness and safety of new drugs. A search of available clinical trials containing pharmacogenetic and PGx information was conducted on ClinicalTrials.gov. The results show there has been an increase in the number of trials containing PGx information since the 2000 s, with particular relevance in the areas of Oncology (28.43%) and Mental Health (10.66%). Most of the clinical trials focus on treatment as their primary purpose. In those clinical trials entries where the specific genes considered for study are detailed, the most frequently explored genes are CYP2D6 (especially in Mental Health and Pain), CYP2C9 (in Hematology), CYP2C19 (in Cardiology and Mental Health) and ABCB1 and CYP3A5 (particularly prominent in Transplantation and Cardiology), among others. Researchers and clinicans should be trained in pharmacogenetics and PGx in order to be able to make a proper interpretation of this data, contributing to better prescribing decisions and an improvement in patients' care, which would lead to the performance of PM.

Tools for Etiologic Diagnosis of Drug-Induced Allergic Conditions

Drug hypersensitivity reactions are a serious concern in clinical practice because they can be severe and result in lifelong sequelae. An accurate diagnosis and identification of the culprit drug is essential to prevent future reactions as well as for the identification of safe treatment alternatives. Nonetheless, the diagnosis can be challenging. In vivo and in vitro tests can be helpful, although none are conclusive; therefore, the tests are not usually performed in isolation but as part of a diagnostic algorithm. In addition, some in vitro tests are only available in research laboratories, and standardization has not been fully accomplished. Collaborating research is needed to improve drug hypersensitivity reaction diagnosis. In this review, we update the current available in vivo and in vitro tools with their pros and cons and propose an algorithm to integrate them into clinical practice.

The Assessment of Meloxicam Phototoxicity in Human Normal Skin Cells: In Vitro Studies on Dermal Fibroblasts and Epidermal Melanocytes

Meloxicam (MLX), which belongs to the oxicam nonsteroidal anti-inflammatory drug derivatives, is an inhibitor of the cyclooxygenase-2 (COX-2) enzyme. Cutaneous adverse effects caused by interaction between UVA radiation and exogenous factors can manifest as phototoxic reactions. Phototoxicity may be a reason for the accumulation of genetic and molecular changes in long-lived cells with low proliferation potential, leading to tumor development. There are several potentially phototoxic drugs, the active component of which is meloxicam. The research aimed to evaluate the influence of MLX and UVAR on skin cells—fibroblasts and melanocytes homeostasis. The obtained results indicated that co-treatment with MLX and UVAR inhibited skin cell proliferation, proportionally to the drug concentration. The observation was confirmed by cytometric analysis of the cell number and viability. The phototoxic effect of MLX was revealed in morphological changes. It was stated that MLX with UVAR lowered the mitochondrial transmembrane potential and changed the cell cycle profile. Additionally, MLX and UVAR caused the disruption of redox homeostasis by lowering the intracellular level of reduced thiols. The presented study revealed that the phototoxic activity of MLX is associated with oxidative stress induction and disruptions in cell homeostasis. The differences in the phototoxic effects of MLX at the cellular level may be related to the different content of melanin pigments.

Antibiotic-Related Adverse Drug Reactions in Patients Treated on the Dermatology Ward of Medical University of Gdańsk

Adverse drug reactions (ADRs) are unexpected reactions to a medication administered in a correct way at a standard dose. Drug-induced skin reactions account for 60-70% of all ADRs. The aim of the study is to determine the prevalence of antibiotic-related dermatological ADR in patients treated in the department of Dermatology, Venerology and Allergology of the University Clinical Center in Gdańsk, Poland, in the years 2004-2021. A retrospective analysis of patients' medical files was conducted in order to identify cases of ADR connected with the use of antibiotics, yielding 84 cases. The most common group of antibiotics were β-lactam, causing ADR in 47 patients. β-lactam antibiotics in our study included amoxicillin, alone and combined with clavulanic acid, and cephalosporins, affecting 22, 18 and 7 patients, respectively. In conclusion, β-lactam antibiotics showed the highest prevalence among antibiotic-induced skin reactions. They accounted for 15% of cases of all dermatological drug reactions and 55% of those caused by antibiotics. Especially amoxicillin, prescribed as a single drug or in combination with clavulanic acid, was commonly the culprit. Due to its wide use in the hospital and outpatient clinic, these adverse reactions have to be kept in mind by both hospital staff and general practitioners.

Genetic Determinants in HLA and Cytochrome P450 Genes in the Risk of Aromatic Antiepileptic-Induced Severe Cutaneous Adverse Reactions

Adverse drug reaction (ADR) is a pressing health problem, and one of the main reasons for treatment failure with antiepileptic drugs. This has become apparent in the event of severe cutaneous adverse reactions (SCARs), which can be life-threatening. In this review, four hypotheses were identified to describe how the immune system is triggered in the development of SCARs, which predominantly involve the human leukocyte antigen (HLA) proteins. Several genetic variations in HLA genes have been shown to be strongly associated with the susceptibility to developing SCARs when prescribed carbamazepine or phenytoin. These genetic variations were also shown to be prevalent in certain populations. Apart from the HLA genes, other genes proposed to affect the risk of SCARs are genes encoding for CYP450 drug-metabolising enzymes, which are involved in the pharmacokinetics of offending drugs. Genetic variants in CYP2C9 and CYPC19 enzymes were also suggested to modulate the risk of SCARs in some populations. This review summarizes the literature on the manifestation and aetiology of antiepileptic-induced SCARs, updates on pharmacogenetic markers associated with this reaction and the implementation of pre-emptive testing as a preventive strategy for SCARs.

Role of Pharmacogenetics in Adverse Drug Reactions: An Update towards Personalized Medicine

Adverse drug reactions (ADRs) are an important and frequent cause of morbidity and mortality. ADR can be related to a variety of drugs, including anticonvulsants, anaesthetics, antibiotics, antiretroviral, anticancer, and antiarrhythmics, and can involve every organ or apparatus. The causes of ADRs are still poorly understood due to their clinical heterogeneity and complexity. In this scenario, genetic predisposition toward ADRs is an emerging issue, not only in anticancer chemotherapy, but also in many other fields of medicine, including hemolytic anemia due to glucose-6-phosphate dehydrogenase (G6PD) deficiency, aplastic anemia, porphyria, malignant hyperthermia, epidermal tissue necrosis (Lyell's Syndrome and Stevens-Johnson Syndrome), epilepsy, thyroid diseases, diabetes, Long QT and Brugada Syndromes. The role of genetic mutations in the ADRs pathogenesis has been shown either for dose-dependent or for dose-independent reactions. In this review, we present an update of the genetic background of ADRs, with phenotypic manifestations involving blood, muscles, heart, thyroid, liver, and skin disorders. This review aims to illustrate the growing usefulness of genetics both to prevent ADRs and to optimize the safe therapeutic use of many common drugs. In this prospective, ADRs could become an untoward "stress test," leading to new diagnosis of genetic-determined diseases. Thus, the wider use of pharmacogenetic testing in the work-up of ADRs will lead to new clinical diagnosis of previously unsuspected diseases and to improved safety and efficacy of therapies. Improving the genotype-phenotype correlation through new lab techniques and implementation of artificial intelligence in the future may lead to personalized medicine, able to predict ADR and consequently to choose the appropriate compound and dosage for each patient.

Molecular and Biochemical Basis of Minocycline-Induced Hyperpigmentation-The Study on Normal Human Melanocytes Exposed to UVA and UVB Radiation

Minocycline is a drug which induces skin hyperpigmentation. Its frequency reaches up to 50% of treated patients. The adverse effect diminishes the great therapeutic potential of minocycline, including antibacterial, neuroprotective, anti-inflammatory and anti-cancer actions. It is supposed that an elevated melanin level and drug accumulation in melanin-containing cells are related to skin hyperpigmentation. This study aimed to evaluate molecular and biochemical mechanism of minocycline-induced hyperpigmentation in human normal melanocytes, as well as the contribution of UV radiation to this side effect. The experiments involved the evaluation of cyto- and phototoxic potential of the drug using cell imaging with light and confocal microscopes as well as biochemical and molecular analysis of melanogenesis. We showed that minocycline induced melanin synthesis in epidermal melanocytes. The action was intensified by UV irradiation, especially with the UVB spectrum. Minocycline stimulated the expression of microphthalmia-associated transcription factor (MITF) and tyrosinase (TYR) gene. Higher levels of melanin and increased activity of tyrosinase were also observed in treated cells. Moreover, minocycline triggered the supranuclear accumulation of tyrosinase, similar to UV radiation. The decreased level of premelanosome protein PMEL17 observed in all minocycline-treated cultures suggests disorder of the formation, maturation or distribution of melanosomes. The study revealed that minocycline itself was able to enhance melanin synthesis. The action was intensified by irradiation, especially with the UVB spectrum. Demonstrated results confirmed the potential role of melanin and UV radiation minocycline-induced skin hyperpigmentation.

Adverse Drug Events in the Oral Cavity

Adverse reactions to medications are common and may have a variety of clinical presentations in the oral cavity. Targeted therapies and new biologic agents have revolutionized the treatment of cancers, autoimmune diseases, and inflammatory and rheumatologic diseases but have also been associated with adverse events in the oral cavity. This review describes the most common clinical presentations of oral mucosal reactions to medications, namely hyposalivation, lichenoid reactions, ulcers, bullous disorders, pigmentation, fibrovascular hyperplasia, reactive keratosis, dysesthesia, osteonecrosis, infection, angioedema, and malignancy.