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Toxicology Reports Dec 2023The case report describes a case of a severe dapsone (more than 200 tablets dapsone 100 mg) and mild methotrexate intoxication (10 tablets methotrexate 10 mg) as an...
The case report describes a case of a severe dapsone (more than 200 tablets dapsone 100 mg) and mild methotrexate intoxication (10 tablets methotrexate 10 mg) as an attempt to commit suicide, resulting in severe cyanosis with elevation in methemoglobin concentration, treated with methylene blue, ascorbic acid, folinic acid, multidose activated charcoal and hemodialysis. Measurements of blood gases, dapsone and methotrexate levels were performed. Furthermore a hepatitis, pulmonary artery thrombus and a strange taste sensation were diagnosed, probably related to dapsone. The patient recovered and was discharged from hospital after five days. Acute intoxication from excessive dapsone intake is uncommon and clear treatment guidelines are lacking. We here report the treatment modalities as a result of a dapsone intoxication, including the effects on the overall condition of the patient.
PubMed: 37868805
DOI: 10.1016/j.toxrep.2023.10.006 -
The Journal of Biological Chemistry Dec 2023Positive heterotropic cooperativity, or "activation," results in an instantaneous increase in enzyme activity in the absence of an increase in protein expression. Thus,...
Positive heterotropic cooperativity, or "activation," results in an instantaneous increase in enzyme activity in the absence of an increase in protein expression. Thus, cytochrome P450 (CYP) enzyme activation presents as a potential drug-drug interaction mechanism. It has been demonstrated previously that dapsone activates the CYP2C9-catalyzed oxidation of a number of nonsteroidal anti-inflammatory drugs in vitro. Here, we conducted molecular dynamics simulations (MDS) together with enzyme kinetic investigations and site-directed mutagenesis to elucidate the molecular basis of the activation of CYP2C9-catalyzed S-flurbiprofen 4'-hydroxylation and S-naproxen O-demethylation by dapsone. Supplementation of incubations of recombinant CYP2C9 with dapsone increased the catalytic efficiency of flurbiprofen and naproxen oxidation by 2.3- and 16.5-fold, respectively. MDS demonstrated that activation arises predominantly from aromatic interactions between the substrate, dapsone, and the phenyl rings of Phe114 and Phe476 within a common binding domain of the CYP2C9 active site, rather than involvement of a distinct effector site. Mutagenesis of Phe114 and Phe476 abrogated flurbiprofen and naproxen oxidation, and MDS and kinetic studies with the CYP2C9 mutants further identified a pivotal role of Phe476 in dapsone activation. MDS additionally showed that aromatic stacking interactions between two molecules of naproxen are necessary for binding in a catalytically favorable orientation. In contrast to flurbiprofen and naproxen, dapsone did not activate the 4'-hydroxylation of diclofenac, suggesting that the CYP2C9 active site favors cooperative binding of nonsteroidal anti-inflammatory drugs with a planar or near-planar geometry. More generally, the work confirms the utility of MDS for investigating ligand binding in CYP enzymes.
Topics: Anti-Inflammatory Agents, Non-Steroidal; Aryl Hydrocarbon Hydroxylases; Cytochrome P-450 CYP2C9; Cytochrome P-450 Enzyme System; Dapsone; Flurbiprofen; Kinetics; Naproxen; Humans
PubMed: 37866634
DOI: 10.1016/j.jbc.2023.105368 -
Journal of Global Antimicrobial... Dec 2023Drug resistance in leprosy is an emerging concern, leading to treatment failures, recurrences, and potential spread of resistant Mycobacterium leprae in the community....
OBJECTIVES
Drug resistance in leprosy is an emerging concern, leading to treatment failures, recurrences, and potential spread of resistant Mycobacterium leprae in the community. In this study, we aimed to assess drug resistance prevalence and patterns amongst leprosy patients at a tertiary care referral hospital in India.
METHODS
Mutations in drug resistance determining regions for dapsone, rifampicin, and ofloxacin of the M. leprae genome in DNA extracted from skin biopsies of 136 leprosy patients (treatment-naive = 67, with persistent skin lesions = 35, with recurrence = 34) were analysed by polymerase chain reaction followed by Sanger sequencing. Wild-type strain (Thai-53) was used as a reference strain.
RESULTS
Resistance mutations were identified in a total of 23 patients, constituting 16.9% of the cohort. Within this subset of 23 cases, resistance to ofloxacin was observed in 17 individuals (12.5%), while resistance to both dapsone and rifampicin was detected in three patients each (2.2% for both). The occurrence of ofloxacin resistance showed minimal disparity between recurrent and treatment-naive cases, at 17.6% and 16.4%, respectively. Dapsone resistance emerged in two treatment-naive cases and one case with persistent skin lesions. Notably, none of the treatment-naive cases or those with recurrence/relapse exhibited rifampicin resistance. Subsequently, no statistically significant correlation was identified between other clinical variables and the presence of antimicrobial resistance.
CONCLUSIONS
The occurrence of resistance to the current multidrug therapy regimen (specifically dapsone and rifampicin) and to ofloxacin, a secondary antileprosy medication in M. leprae, represents a concerning scenario. This calls for an expansion towards bactericidal drug options and the establishment of robust surveillance for drug resistance in countries burdened with high leprosy rates. Moreover, the introduction of stringent antimicrobial stewardship initiatives is imperative. As a single centre study, it represents a limited, cross-sectional view of the real situation in the field.
Topics: Humans; Mycobacterium leprae; Rifampin; Leprostatic Agents; Ofloxacin; Drug Therapy, Combination; Cross-Sectional Studies; Drug Resistance, Bacterial; Leprosy; Dapsone; India
PubMed: 37852372
DOI: 10.1016/j.jgar.2023.10.006 -
Journal of Medical Economics 2023Studies found a strong association between allele and co-trimoxazole-induced severe cutaneous adverse reactions (SCARs). Genetic screening before initiation of...
Cost-effectiveness analysis of HLA-B*13:01 screening for the prevention of co-trimoxazole-induced severe cutaneous adverse reactions among HIV-infected patients in Thailand.
Studies found a strong association between allele and co-trimoxazole-induced severe cutaneous adverse reactions (SCARs). Genetic screening before initiation of co-trimoxazole may decrease the incidence of co-trimoxazole-induced SCARs. This study aims to evaluate the cost-effectiveness of screening before co-trimoxazole initiation in HIV-infected patients in Thailand. A combination of a decision tree model and a Markov model was used to estimate lifetime costs and outcomes of two strategies including 1) screening before co-trimoxazole initiation and 2) usual practice from a societal perspective. Alternative drugs are not considered because dapsone (the second-line drug) also presents a genetic risk. Input parameters were obtained from literature, government documents, and part of the TREAT Asia HIV Observational Database (TAHOD). One-way sensitivity analyses and probabilistic analyses were performed to determine robustness of the findings. screening resulted in 0.0061 quality-adjusted life years (QALYs) loss with an additional cost of 370 THB ($11.84). At the cost-effectiveness threshold of 160,000 THB ($5,112.85), the probability of the genetic screening strategy being cost-effective is 9.54%. This analysis demonstrated that allele screening before initiation of co-trimoxazole among HIV-infected patients is unlikely to be cost-effective in Thailand. Our findings will help policymakers make an evidence-informed decision making.
Topics: Humans; Trimethoprim, Sulfamethoxazole Drug Combination; Cost-Effectiveness Analysis; Thailand; Cicatrix; Cost-Benefit Analysis; HLA-B Antigens; HIV Infections
PubMed: 37830976
DOI: 10.1080/13696998.2023.2270868 -
Asian Pacific Journal of Allergy and... Sep 2023Mast cells and eosinophils are considered pivotal contributors to the pathogenesis of chronic spontaneous urticaria (CSU). However, emerging evidence suggests that...
Mast cells and eosinophils are considered pivotal contributors to the pathogenesis of chronic spontaneous urticaria (CSU). However, emerging evidence suggests that neutrophils also play a central role. Cutaneous mast cells and macrophages orchestrate the recruitment of neutrophils through the regulation and activation of diverse processes, including heightened local vascular permeability and chemokine release. Studies have demonstrated increased activation and elevated levels of neutrophil-related cytokines in CSU patients. Moreover, neutrophils have been proposed as antigen-presenting cells during the late-phase reaction of immunoglobulin E-mediated allergy and have been associated with the expression of calcitonin gene-related protein and vascular endothelial growth factor in CSU. Histopathological analysis of lesional skin in CSU patients revealed significantly higher eosinophil and neutrophil counts than unaffected skin. However, the extent of neutrophil infiltration in the skin does not appear to correlate with the number of neutrophils in peripheral blood. The utility of the neutrophil-lymphocyte ratio as a marker for disease activity or remission in CSU remains inconclusive. Neutrophil-targeted therapy may confer benefits for CSU patients who exhibit resistance to antihistamines. Omalizumab has demonstrated its ability to reduce neutrophil counts, the neutrophil-lymphocyte ratio, and the neutrophil-monocyte ratio in peripheral blood. While dapsone and colchicine are recommended as alternative treatment options for CSU, their evidential support from published studies remains limited. Inhibitors targeting interleukin-1 and neutrophil-related cytokines have been proposed as potential therapeutic interventions for patients exhibiting neutrophil predominance. Further research is warranted to gain deeper insights into the involvement of neutrophils in CSU and to explore potential therapeutic interventions.
Topics: Humans; Urticaria; Neutrophils; Mast Cells; Vascular Endothelial Growth Factor A; Chronic Urticaria; Cytokines; Chronic Disease
PubMed: 37804482
DOI: 10.12932/AP-180623-1638 -
Pharmaceutics Sep 2023Several studies have demonstrated the feasibility of in situ co-crystallization in different pharmaceutical processes such as spray drying, hot melt extrusion, and...
Several studies have demonstrated the feasibility of in situ co-crystallization in different pharmaceutical processes such as spray drying, hot melt extrusion, and fluidized bed granulation (FBG) to produce co-crystal-in-excipient formulations. However, no previous studies have examined such a one step in situ co-crystallization process for co-crystal formulations where the coformer is a polymer. In the current study, we explored the use of FBG to produce co-crystal granules of dapsone (DAP) and different molecular weight polyethylene glycols (PEGs). Solvent evaporation (SE) was proven to generate DAP-PEGs co-crystals at a particular weight ratio of 55:45 / between DAP and PEG, which was subsequently used in FBG, using microcrystalline cellulose and hydroxypropyl methyl cellulose as filler excipient and binder, respectively. FBG could generate co-crystals with higher purity than SE. Granules containing DAP-PEG 400 co-crystal could be prepared without any additional binder. DAP-PEG co-crystal granules produced by FBG demonstrated superior pharmaceutical properties, including flow properties and tableting properties, compared to DAP and DAP-PEG co-crystals prepared by SE. Overall, in situ co-crystallization via FBG can effectively produce API-polymer co-crystals and enhance the pharmaceutical properties.
PubMed: 37765298
DOI: 10.3390/pharmaceutics15092330 -
Microorganisms Sep 2023Twenty-five patients with relapsing and remitting Borreliosis, Babesiosis, and bartonellosis despite extended anti-infective therapy were prescribed double-dose dapsone...
Comparison of the Efficacy of Longer versus Shorter Pulsed High Dose Dapsone Combination Therapy in the Treatment of Chronic Lyme Disease/Post Treatment Lyme Disease Syndrome with Bartonellosis and Associated Coinfections.
Twenty-five patients with relapsing and remitting Borreliosis, Babesiosis, and bartonellosis despite extended anti-infective therapy were prescribed double-dose dapsone combination therapy (DDDCT), followed by one or several courses of High Dose Dapsone Combination Therapy (HDDCT). A retrospective chart review of these 25 patients undergoing DDDCT therapy and HDDCT demonstrated that 100% improved their tick-borne symptoms, and patients completing 6-7 day pulses of HDDCT had superior levels of improvement versus 4-day pulses if was present. At the completion of treatment, 7/23 (30.5%) who completed 8 weeks of DDDCT followed by a 5-7 day pulse of HDDCT remained in remission for 3-9 months, and 3/23 patients (13%) who recently finished treatment were 1 ½ months in full remission. In conclusion, DDDCT followed by 6-7 day pulses of HDDCT could represent a novel, effective anti-infective strategy in chronic Lyme disease/Post Treatment Lyme Disease Syndrome (PTLDS) and associated co-infections, including , especially in individuals who have failed standard antibiotic protocols.
PubMed: 37764145
DOI: 10.3390/microorganisms11092301 -
Materials (Basel, Switzerland) Sep 2023Dapsone is an effective antibacterial drug used to treat a variety of conditions. However, the aqueous solubility of this drug is limited, as is its permeability. This...
Dapsone is an effective antibacterial drug used to treat a variety of conditions. However, the aqueous solubility of this drug is limited, as is its permeability. This study expands the available solubility data pool for dapsone by measuring its solubility in several pure organic solvents: N-methyl-2-pyrrolidone (CAS: 872-50-4), dimethyl sulfoxide (CAS: 67-68-5), 4-formylmorpholine (CAS: 4394-85-8), tetraethylene pentamine (CAS: 112-57-2), and diethylene glycol bis(3-aminopropyl) ether (CAS: 4246-51-9). Furthermore, the study proposes the use of intermolecular interactions as molecular descriptors to predict the solubility of dapsone in neat solvents and binary mixtures using machine learning models. An ensemble of regressors was used, including support vector machines, random forests, gradient boosting, and neural networks. Affinities of dapsone to solvent molecules were calculated using COSMO-RS and used as input for model training. Due to the polymorphic nature of dapsone, fusion data are not available, which prohibits the direct use of COSMO-RS for solubility calculations. Therefore, a consonance solvent approach was tested, which allows an indirect estimation of the fusion properties. Unfortunately, the resulting accuracy is unsatisfactory. In contrast, the developed regressors showed high predictive potential. This work documents that intermolecular interactions characterized by solute-solvent contacts can be considered valuable molecular descriptors for solubility modeling and that the wealth of encoded information is sufficient for solubility predictions for new systems, including those for which experimental measurements of thermodynamic properties are unavailable.
PubMed: 37763610
DOI: 10.3390/ma16186336 -
JAAD Case Reports Oct 2023
PubMed: 37731672
DOI: 10.1016/j.jdcr.2023.08.011 -
Development of cyclosporine-induced linear IgA bullous dermatosis despite concurrent use of dapsone.JAAD Case Reports Oct 2023
PubMed: 37731671
DOI: 10.1016/j.jdcr.2023.08.008