First-line Antitubercular Drugs Research Articles

Pharmaceutical salt of isoniazid−orotic acid with optimized solubility, dissolution rate, and tabletability

Isoniazid (INH) is a first-line antitubercular drug characterized by its high solubility and rapid absorption following oral administration, which poses challenges in maintaining sustained therapeutic concentrations. To address this issue, we have developed a novel pharmaceutical salt of INH with orotic acid (OA). Single-crystal X-ray diffraction (XRD) analysis revealed that intermolecular proton transfer occurs between the carboxyl group of OA and the pyridine nitrogen site of INH, resulting in a salt comprising INHH+ cations and OA− anions. Solubility and dissolution studies indicated that INH−OA exhibits significantly reduced solubility and decelerated intrinsic dissolution rate (IDR). Specifically, solubility reductions were observed to be 74.24% in pH 1.2 HCl solution and 90.29% in pH 6.8 phosphate buffer solution. The IDR of the salt was found to be 2.62% and 0.96% of that of pure INH in pH 1.2 and pH 6.8 aqueous media, respectively. Additionally, INH−OA demonstrated improved tabletability. These findings suggest that the formation of this salt significantly enhances the pharmaceutical properties of INH.

Pharmacokinetics-pharmacodynamics of first-line antitubercular drugs: a comparative study in tuberculosis patients with and without concomitant diabetes mellitus.

To observe the variability in the plasma concentrations and pharmacokinetic-pharmacodynamic (PK-PD) profiles of first-line antitubercular drugs in pulmonary tuberculosis (TB) patients with and without diabetes mellitus (DM). Newly diagnosed pulmonary TB patients aged 18-60years with or without DM were included in the study. Group I (n = 20) included patients with TB, whereas group II (n = 20) included patients withboth TB and DM. After 2 weeks of therapy, plasma concentrations and other PK-PD parameters were determined. Improvements in clinical features, X-ray findings, sputum conversion, and adverse drug reactions (ADRs) were assessed after 2 months of therapy. Isoniazid displayed non-significantly higher plasma concentrations in diabetic patients, along with a significantly (P < 0.05) longer elimination half-life (t1/2). Rifampicin plasma concentrations at 4, 8, and 12 h were significantly (P < 0.05) lower, and it displayed significantly (P < 0.05) lower area underthe curve (AUC0-12 and AUC0-∞), shorter t1/2, higher clearance (Cl), and a lower AUC0-∞/MIC ratio in diabetic patients. Pyrazinamide and ethambutol showed non-significantly higher plasma concentrations, AUC0-12, AUC0-∞, and t1/2 in diabetic patients. The improvements in clinical features, X-ray findings, sputum conversion, and ADRs were comparable in both groups. The presence of DM in TB patients affects the PK-PD parameters of isoniazid, rifampicin, pyrazinamide, and ethambutol variably in the Indian population. Studies with a larger number of patients are required to further elucidate the role of DM on the PK-PD profile of first-line antitubercular drugs and treatment outcomes in TB patients with concomitant DM. CTRI/2021/08/035578 dated 11/08/2021.

Characteristics of isoniazid-induced psychosis: a systematic review of case reports and case series

PurposeIsoniazid, a first-line antitubercular drug, is associated with nervous system adverse drug reactions such as seizures, peripheral neuropathy, and psychosis. This systematic review of case reports and case series aimed to characterize the demographic, social, and clinical factors associated with isoniazid-induced psychosis in patients with active tuberculosis (TB) and those who received isoniazid for latent TB infection (LTBI).MethodsWe comprehensively searched the Embase, PubMed, and Scopus databases to identify relevant studies published between the date of inception of the database and June 2024.ResultsA total of 28 studies, including 21 case reports and 7 case series involved 37 patients who developed isoniazid-induced psychosis. A higher frequency of isoniazid-induced psychosis was observed during the first 2 months of treatment, with a relatively early onset observed among patients aged 18 years or less. Delusions and/or hallucinations are the common symptoms of isoniazid-induced psychosis. Psychomotor disturbances, disorganized speech or formal thought disorder, disorganized or abnormal behaviour, and neuropsychiatric symptoms (sleep disturbances, hostility or aggression, confusion, affective symptoms, anxiety symptoms, and cognitive difficulties) were the other symptoms observed in the included studies. More than 80% of cases rechallenged with isoniazid resulted in the recurrence of psychotic symptoms.ConclusionPatients with TB and LTBI should be assessed for psychotic and neuropsychiatric symptoms during isoniazid therapy, mainly in the first 2 months. Further research is required to understand the impact of underlying risk factors, such as genetic predisposition and isoniazid pharmacokinetics, as well as the clinical utility and dosage recommendations of pyridoxine for managing isoniazid-induced psychosis.

Study of risk factors and clinical management of patients with clinical non-response due to low plasma levels of anti-tubercular drugs.

This study was carried out to assess the role of therapeutic drug monitoring of crucial first-line anti-tubercular drugs: rifampicin (R) and isoniazid (H) among 75 non-responding proven drug-sensitive tuberculosis patients on treatment followed by intervention in field conditions. The intervention was done in the form of either an increase in the dosage of R and H in patients with minimally low drug levels or a modification of the regimen in a certain group of patients with significantly low drug levels by augmenting it with three or four second-line drugs in addition to standard first-line drugs. This study also aimed to determine the relationship between the measured plasma concentration of anti-tubercular drugs and various demographic, microbiological, radiological, and malabsorption factors and the presence of co-morbidities affecting them. The study also focused on the clinical impact of the intervention for low plasma levels of anti-TB drugs on TB treatment outcomes. In our study overall, 85.5% of patients had low levels of any drug. In 85.3% of patients, R levels were low, and in 39.1%, H levels were low. On univariate analysis, low body mass index (BMI), hypoalbuminemia, bilateral disease on chest X-rays, and the presence of cavities were found to be significantly associated with low drug levels, while none of the factors were independently significantly associated. Low BMI, pulmonary tuberculosis and disseminated tuberculosis, far-advanced disease and bilateral disease on chest X-ray, presence of cavities, and only low R levels were associated with unfavorable outcomes, with none of the factors found to be significant on multivariate analysis. In our study, it was seen that the treatment outcome was favorable in 59.6% of patients in whom this intervention was done by augmenting the treatment regimen with three/four second-line drugs along with increasing the dose of R and H. To conclude, various factors may be associated with low plasma levels of anti-tubercular drugs. If such patients show clinical non-response after >6 months of treatment and have significantly low drug levels, with an absence of drug resistance, their treatment regimen may need augmentation with three/four second-line drugs along with an increase in the dose of R and H, which may lead to a favorable outcome.

Evaluation of Colorimetric Nitrate Reductase Assay in Liquid Medium for Detection of Resistance to First-line Antitubercular Drugs.

On a global scale, India holds the distinction of having the greatest number of tuberculosis (TB) cases caused by Mycobacterium tuberculosis (MTB) complex. The study aimed at evaluating the sensitivity, specificity, accuracy, cost, rapidity, and feasibility of the performance of the colorimetric nitrate reductase-based antibiotic susceptibility (CONRAS) test against the indirect proportion method (IPM) on Lowenstein-Jensen media as the gold standard. A comparative cross-sectional study was performed on 51 MTB isolates. Fresh subcultures were used for drug susceptibility testing by IPM on the Lowenstein-Jensen medium and the CONRAS method in liquid medium. Quality control for drug susceptibility testing was done using a known sensitive strain of MTB (H37Rv) and strains resistant to both isoniazid (INH) and rifampicin (RIF) - multidrug-resistant (MDR), mono-resistant to RIF, streptomycin (STM), and ethambutol (EMB). Statistical analysis was performed using MedCalc software (Version 20.027). CONRAS, carried out in microfuge tubes, was cost-efficient and easy to perform/interpret with most results being available in 10 days compared to 42 days in the case of IPM. The sensitivity, specificity, and accuracy of RIF and INH were 100%, 97.37%, and 98.04 and 93.33%, 97.59%, and 96.08%, respectively, which translates into an almost perfect agreement between the two methods as indicated by κ value of 0.905 and 0.949, respectively, for the two drugs. The performance of CONRAS was less satisfactory for STM and EMB when compared to IPM. CONRAS may serve as a useful test for the detection of MDR-TB because of its accuracy, low cost, ease of performance/interpretation, and rapidity when compared to IPM on LJ medium. It does not involve the use of expensive reagents and equipment, as is the case with molecular methods like GeneXpert and line probe assay, making it a suitable option for the detection of MDR-TB in resource-poor settings.

An observed repeat case of drug reaction with eosinophilia and systemic symptoms syndrome with modified anti-tuberculosis therapy: a case report

Drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome, while uncommon, presents a potentially hazardous condition. It is a drug-induced multi‑system immunological hypersensitivity reaction, characterized by the triad of fever, rash, and internal organ involvement. This is a case report of a 60-year-old Indian female who developed a repeat episode of DRESS syndrome following modified anti-tuberculosis therapy (ATT). She had a past history of DRESS syndrome caused by first-line antitubercular drugs. This case report aims to highlight the challenges in managing DRESS syndrome in the context of tuberculosis (TB) treatment, as well as to emphasize the importance of prompt withdrawal of the culprit drugs and immediate initiation of appropriate supportive care. This case report also highlights the high risk of recurrence of DRESS syndrome following the re-administration of the offending medication, especially antitubercular drugs.

Diagnostic Performance and Comparative Analysis of Conventional Drug Susceptibility Testing, Line Probe Assay, and GeneXpert in Extrapulmonary Tuberculosis Cases: A Cross-sectional Observational Study

Introduction: Tuberculosis (TB), a known threat to mankind for ages, causes a significant burden on healthcare worldwide. The alarming rise of Extrapulmonary Tuberculosis (EPTB) has led healthcare professionals to opt for molecular diagnostics. Despite the availability of rapid diagnostics, conventional culture Drug Susceptibility Testing (DST) is still considered the gold standard in diagnosing TB. Aim: To assess the diagnostic accuracy of culture DST which is considered the gold standard. Materials and Methods: This cross-sectional observational study included 150 suspected EPTB patients and was conducted over a period of one year (September 2018 to August 2019) at Lokmanya Tilak Municipal Medical College and Sion Hospital (LTMMC), a tertiary care hospital in central Mumbai, Maharashtra, India. The hospital is located adjacent to Dharavi, the largest slum area with a high population density, which contributes to the majority of patients attending clinics. Patients attending the pulmonary medicine Outpatient Department (OPD) with extrapulmonary manifestations and suspected cases of EPTB were enrolled in the study. Samples, excluding sputum, were sent to the Department of Microbiology, LTMMC, Sion Hospital for GeneXpert analysis. The samples were further evaluated by microscopy, GeneXpert, and culture DST to detect the presence of Mycobacterium tuberculosis (M. tuberculosis) and drug susceptibility, respectively. Patients positive for Pulmonary Tuberculosis (PTB) were excluded from the study. Categorical variables were described using percentages. A Chi-square test was applied, and a p-value of &lt;0.05 was considered significant. All statistical analyses were performed using SPSS statistical software (IBM SPSS version 26.0, Armonk, N.Y.). Results: Out of the 150 extrapulmonary samples, 23 (15.33%) samples were culture positive for M. tuberculosis and were subjected to DST using the 1% proportion method and GeneXpert assay. The MDR isolates were tested using the firstline Line Probe Assay (LPA). Eleven (47.8%) showed resistance to first-line antitubercular drugs. Among the 12 new cases, only 2 (16.7%) showed resistance compared to 9 (81.8%) in previously treated cases. A discordance of 8.7% was observed between DST with GeneXpert and LPA. Additionally, a discordance of 8.7% was observed between DST and LPA for rifampicin resistance and 4.3% for isoniazid resistance. Conclusion: The paucibacillary nature of extrapulmonary samples contributes to the challenging diagnosis of EPTB cases, leading to increased drug resistance. Highlighting the importance of the conventional solid culture DST method, this study strongly recommends the use of conventional DST accompanied by LPA for extrapulmonary cases.

Development of a HPLC Method for Analysis of a Combination of Clofazimine, Isoniazid, Pyrazinamide, and Rifampicin Incorporated into a Dermal Self-Double-Emulsifying Drug Delivery System.

We describe the development and validation of a new high performance liquid chromatography (HPLC) method for analysis of a combination of the first-line anti-tubercular drugs isoniazid, pyrazinamide, and rifampicin together with clofazimine. This is a unique challenge since clofazimine and rifampicin are relatively highly lipophilic drugs, whereas isoniazid and pyrazinamide are considerably more hydrophilic. Thus, clear separation of peaks and quantification of four individual drugs can present difficulties during the development of an analytical method. Detection was established at two wavelengths-254 nm for isoniazid and pyrazinamide and 320 nm for clofazimine and rifampicin. Gradient elution was employed using 0.1% aqueous formic acid (A) and acetonitrile (B); clear separation of the four drugs was achieved within 10 min. A linear relationship was indicated by a correlation coefficient (r2) of 0.9999 for each anti-tubercular drug, respectively. The limit of detection (LOD) for the individual drugs was 0.70 µg/mL (isoniazid), 0.30 µg/mL (pyrazinamide), 0.20 µg/mL (rifampicin) and 0.20 µg/mL (clofazimine). Precision experiments rendered a mean recovery percentage of 101.25% (isoniazid), 98.70% (pyrazinamide), 99.68% (rifampicin) and 97.14% (clofazimine). This HPLC method was validated and is reliable, repeatable, and accurate for the purpose of conducting simultaneous HPLC analyses of the four anti-tubercular drugs.

Adverse Drug Reaction Patterns of First-line Anti-tubercular Drugs among Saharia Tuberculosis Patients: An Observational Study in Particularly Vulnerable Tribal Group of Madhya Pradesh, India.

The Saharia tribe of Madhya Pradesh has a very high tuberculosis (TB) burden. However, there is no report of adverse drug reaction (ADR) available in patients receiving anti-TB chemotherapy in the community. Reporting and monitoring of ADRs among TB patients is still rare in marginalized communities. An observational prospective study was performed from November 2019 to June 2020 to assess the patterns of ADRs in 250 Saharia TB patients, who were prescribed Category-I daily DOTS (HRZE) by the physician. Both male and female participants equally experienced ADR during the treatment, but relatively more females (92.6%) than males (88.6%) reported ADR during Phase I. Out of 250 patients, 224 patients (89.6%) experienced one or more ADRs in Phase I. The central nervous system-related (75.6%) ADR was mostly reported followed by any gastrointestinal (74.4%), cardiovascular (49.2%) and any dermatological related (44.4%) ADRs. It is paramount to timely monitor and proactively manages ADRs pertaining to anti-TB drug treatment with minimal alteration in the treatment course.

A Comprehensive Investigation of the Interactions between Proteins and Ligands in the Crystal Structures of Mycobacterium Tuberculosis

Mycobacterium tuberculosis (MTB), an acid-fast aerobic bacterium that may grow on gram stain as either a gram-positive or gram-negative bacterium, is the disease-causing agent of tuberculosis (TB). Rifampin, isoniazid, pyrazinamide and ethambutol, the first-line anti-tubercular drugs, can all have hepatotoxic side effects. The new medicine needs to work through a novel mode of action or to a novel target, be more active than presently available treatments, and shorten the course of treatment for the MDR-TB and XDR-TB, also active against both active and latent bacteria, and does not interact with antiretroviral medications because many TB patients also have HIV. Additionally, it must work well with other anti-TB medications to form at least an effective three-drug regimen. This article discusses the analysis of a few FDA-approved anti-tubercular medications and their binding locations with respective targeted proteins. This mainly focuses on the amino acids of the proteins that are responsible for the formation of interactions with a drug molecule. So, researchers can modify the existing drugs or their derivatives or can construct a new molecule according to the binding sites of enzymes corresponding to mycobacterium tuberculosis.

New approach to rifampicin stability and first-line anti-tubercular drug pharmacokinetics by UPLC-MS/MS

Successful tuberculosis (TB) therapy requires achieving sufficient exposure to multiple drugs. Limited stability of several first-line anti-TB drugs might compromise reliable therapeutic drug monitoring (TDM). We developed and validated a sensitive and selective UPLC-MS/MS method for simultaneous quantification of isoniazid (INH), pyrazinamide (PZA), rifampicin (RIF), its metabolite 25-desacetylrifampicin and degradation products: rifampicin quinone and 3-formyl-rifampicin. Analysis was completed from a very small plasma volume (20 µL) using only protein precipitation with methanol. Chromatographic separation was achieved on a Kinetex Polar C18 column (2.6 µm; 150 × 3 mm) with a mobile phase consisting of 5 mM ammonium acetate and acetonitrile, both containing 0.1 % formic acid, in gradient elution. The analytes were detected using a positive ionization mode by multiple reaction monitoring. The LLOQ for RIF and its degradation products was 0.1 µg/mL, 0.05 µg/mL for INH, and 0.2 µg/mL for PZA. The method was validated based on the FDA guidance. The application of the method was confirmed in the analysis of RIF, INH, and PZA, as well as RIF metabolism/degradation products in plasma samples of patients with TB. Based on the detailed stability study of the analyzed compounds at various storage conditions, we proposed recommendations for handling the plasma and serum samples in TDM and other pharmacokinetic studies.

Correlation of N-acetyltransferase 2 genotype and acetylation status with plasma isoniazid concentration and its metabolic ratio in ethiopian tuberculosis patients

Unfavorable treatment outcomes for tuberculosis (TB) treatment might result from altered plasma exposure to antitubercular drugs in TB patients. The present study investigated the distribution of the N-Acetyltransferase 2 (NAT2) genotype, isoniazid acetylation status, genotype–phenotype concordance of NAT2, and isoniazid plasma exposure among Ethiopian tuberculosis patients. Blood samples were collected from newly diagnosed TB patients receiving a fixed dose combination of first-line antitubercular drugs daily. Genotyping of NAT2 was done using TaqMan drug metabolism assay. Isoniazid and its metabolite concentration were determined using validated liquid chromatography-tandem mass spectrometry (LC–MS/MS). A total of 120 patients (63 male and 57 female) were enrolled in this study. The mean daily dose of isoniazid was 4.71 mg/kg. The frequency of slow, intermediate, and fast NAT2 acetylators genotypes were 74.2%, 22.4%, and 3.3% respectively. The overall median isoniazid maximum plasma concentration (Cmax) was 4.77 µg/mL and the AUC0–7 h was 11.21 µg.h/mL. The median Cmax in slow, intermediate, and fast acetylators were 5.65, 3.44, and 2.47 μg/mL, respectively. The median AUC0–7 h hour in slow, intermediate, and fast acetylators were 13.1, 6.086, and 3.73 mg•h/L, respectively. The majority (87.5%) of the study participants achieved isoniazid Cmax of above 3 µg/mL, which is considered a lower limit for a favorable treatment outcome. There is 85% concordance between the NAT2 genotype and acetylation phenotypes. NAT2 genotype, female sex, and dose were independent predictors of Cmax and AUC0–7 h (p < 0.001). Our finding revealed that there is a high frequency of slow NAT2 genotypes. The plasma Cmax of isoniazid was higher in the female and slow acetylators genotype group. The overall target plasma isoniazid concentrations in Ethiopian tuberculosis patients were achieved in the majority of the patients. Therefore, it is important to monitor adverse drug reactions and the use of a higher dose of isoniazid should be closely monitored.

Drug-Induced Hypersensitivity Reaction and Re-Introduction of Anti-Tubercular Drugs (ATT): A Case Report and Review of Literature

Tuberculosis (TB) is a communicable disease caused by the bacillus Mycobacterium tuberculosis and is the leading cause of death by a single infectious agent overall. According to the WHO Global TB Report, India contributes to 26% of the global burden of TB. Currently, a four-drug regimen comprising Rifampicin, Isoniazid, Pyrazinamide, and Ethambutol is approved for the treatment of drug-sensitive TB. The management of cutaneous adverse drug reactions to anti-tubercular drugs is akin to a double-edged sword, with discontinuation of ATT increasing the risk of developing disseminated and drug-resistant tuberculosis, and continuation leading to persistence or exacerbation of the adverse drug reaction (ADR). The risk of developing an ADR to anti-tubercular therapy (ATT) varies from 8 to 85% in various studies [10]. The prevalence of rashes associated with ATT shows that the maculopapular rash (42.5%) is the most frequently observed type, followed by urticarial, lichenoid, DRESS, AGEP, and exfoliative dermatitis (17). The drugs associated with Cutaneous ADRs from the lowest to the highest risk are Isoniazid, Rifampicin, Pyrazinamide, Ethionamide, Cycloserine, Ethambutol, Para-aminosalicylic acid (PAS), and Streptomycin (25). We present a case and approach to the re-introduction of first-line anti-tubercular drugs after hypersensitivity with fixed-dose combinations.&#x0D; Keywords: Tuberculosis, Mycobacterium tuberculosis, adverse drug reaction, anti-tubercular therapy

Determinants of adverse reactions to first-line antitubercular medicines: a prospective cohort study

BackgroundThe success of tuberculosis treatment relies on patients adhering to their medication regimen consistently. However, adherence levels tend to decrease among patients who experience adverse drug reactions to antitubercular medications, leading to suboptimal treatment outcomes. Hence, this study aimed to examine the types, incidence rates, and severity of adverse reactions caused by first-line antitubercular drugs. Additionally, it aimed to identify factors associated with the development of these reactions. By doing so, the study aimed to facilitate the provision of personalized and effective treatment to patients, ultimately improving treatment outcomes.MethodsNewly diagnosed patients with active tuberculosis were monitored from the start of their treatment until the completion of therapy. Any adverse reactions to anti-TB drugs that they encountered were carefully recorded. The collected data were analyzed using appropriate statistical methods such as analysis of variance, Chi-squared test, Fisher's exact test, and independent t-tests. Logistic regression was employed to assess the association between adverse drug reactions and various socio-demographic and clinical factors of the patients, using odds ratios as a measure of association.ResultsAmong the 378 patients included in the study, 181 individuals (47.9%) reported experiencing at least one adverse drug reaction, with an incidence rate of 1.75 events per 100-person months. The majority of these reactions occurred during the intensive phase of treatment. The gastrointestinal tract was the most commonly affected system, followed by the nervous system and skin. Patients aged over 45 years (OR = 1.55, 95% CI 1.01–2.39, p = 0.046) and those with extrapulmonary tuberculosis (OR = 2.41, 95% CI 1.03–5.64) were more likely to develop gastrointestinal reactions. Female gender was a significant predictor of both skin (OR = 1.78, 95% CI 1.05–3.02, p = 0.032) and nervous system (OR = 1.65, 95% CI 1.07–2.55, p = 0.024) reactions. Additionally, alcohol use and HIV infection were identified as independent predictors of adverse drug reactions affecting all three systems.ConclusionSignificant risk factors for developing antitubercular drug adverse reactions include alcohol consumption, cigarette smoking, being HIV positive, female gender and extrapulmonary tuberculosis.

Molecular and cellular remodeling of HepG2 cells upon treatment with antitubercular drugs.

Drug-induced liver injury (DILI) is an adverse outcome of the currently used tuberculosis treatment regimen, which results in patient noncompliance, poor treatment outcomes, and the emergence of drug-resistant tuberculosis. DILI is primarily caused by the toxicity of the drugs and their metabolites, which affect liver cells, biliary epithelial cells, and liver vasculature. However, the precise mechanism behind the cellular damage attributable to first-line antitubercular drugs (ATDs), as well as the effect of toxicity on the cell survival strategies, is yet to be elucidated. In the current study, HepG2 cells upon treatment with a high concentration of ATDs showed increased perforation within the cell, cuboidal shape, and membrane blebbing as compared with control/untreated cells. It was observed that ATD-induced toxicity in HepG2 cells leads to altered mitochondrial membrane permeability, which was depicted by the decreased fluorescence intensity of the MitoRed tracker dye at higher drug concentrations. In addition, high doses of ATDs caused cell damage through an increase in reactive oxygen species production in HepG2 cells and a simultaneous reduction in glutathione levels. Further, high dose of isoniazid (50-200 mM), pyrazinamide (50-200 mM), and rifampicin (20-100 µM) causes cell apoptosis and affects cell survival during toxic conditions by decreasing the expression of potent autophagy markers Atg5, Atg7, and LC3B. Thus, ATD-mediated toxicity contributes to the reduced ability of hepatocytes to tolerate cellular damage caused by altered mitochondrial membrane permeability, increased apoptosis, and decreased autophagy. These findings further emphasize the need to develop adjuvant therapies that can mitigate ATD-induced toxicity for the effective treatment of tuberculosis.

N-Acylated Ciprofloxacin Derivatives: Synthesis and In Vitro Biological Evaluation as Antibacterial and Anticancer Agents.

A novel series of N-acylated ciprofloxacin (CP) conjugates 1-21 were synthesized and screened as potential antimicrobial agents. Conjugates 1 and 2 were 1.25-10-fold more potent than CP toward all Staphylococci (minimal inhibitory concentration 0.05-0.4 μg/mL). Most of the chloro- (3-7), bromo- (8-11), and CF3-alkanoyl (14-16) derivatives expressed higher or comparable activity to CP against selected Gram-positive strains. A few CP analogues (5, 10, and 11) were also more effective toward the chosen clinical Gram-negative rods. Conjugates 5, 10, and 11 considerably influenced the phases of the bacterial growth cycle over 18 h. Additionally, compounds 2, 4-7, 9-12, and 21 exerted stronger tuberculostatic action against three Mycobacterium tuberculosis isolates than the first-line antitubercular drugs. Amides 1, 2, 5, 6, 10, and 11 targeted gyrase and topoisomerase IV at 2.7-10.0 μg/mL, which suggests a mechanism of antibacterial action related to CP. These findings were confirmed by molecular docking studies. In addition, compounds 3 and 15 showed high antiproliferative activities against prostate PC3 cells (IC50 2.02-4.8 μM), up to 6.5-2.75 stronger than cisplatin. They almost completely reduced the growth and proliferation rates in these cells, without a cytotoxic action against normal HaCaT cell lines. Furthermore, derivatives 3 and 21 induced apoptosis/necrosis in PC3 cells, probably by increasing the intracellular ROS amount, as well as they diminished the IL-6 level in tumor cells.

Cisatracurium besylate rescues Mycobacterium Tuberculosis-infected macrophages from necroptosis and enhances the bactericidal effect of isoniazid

ObjectiveTuberculosis is the leading killer among the chronic single-source infectious diseases. Mycobacterium tuberculosis can induce necrotic-dominant multiple modes of cell death in macrophages, which accelerates bacterium dissemination and expands tissue injury in host lungs. Mining drugs to counteract Mycobacterium tuberculosis-induced cell death would be beneficial to tuberculosis patients. MethodsIn this study, the protective drug was screened out from the FDA-approved drug library in Mycobacterium tuberculosis-infected macrophages with CCK-8 assay. The death mode regulated by the drug was identified using transcriptomic sequencing, cytomorphological observation, and in the experimental mouse Mycobacterium tuberculosis-infection model. The functional mechanism was explored using western blot, co-immunoprecipitation, and DARTS assay. The intracellular bacterial survival was detected using colony forming unit assays. ResultsCisatracurium besylate was identified to be highly protective for the viability of macrophages during Mycobacterium tuberculosis infection via inhibiting necroptosis. Cisatracurium besylate prevented RIPK3 to be associated with the executive molecule MLKL for forming the necroptotic complex, resulting in the inhibition of MLKL phosphorylation and pore formation on cell membrane. However, Cisatracurium besylate did not interfere with the association between RIPK3 with its upstream kinase RIPK1 or ZBP1 but regulated RIPK3 autophosphorylation. Moreover, Cisatracurium besylate significantly inhibited the expansion of intracellular Mycobacterium tuberculosis both in vitro and in vivo, which also displayed a strong auxiliary bacteriostatic effect to support the therapeutic efficacy of isoniazid and rifampicin, the first-line anti-tubercular drugs. ConclusionCisatracurium besylate performs anti-Mycobacterium tuberculosis and anti-necroptotic roles, which potentiates its application to be an adjuvant drug for antituberculosis therapy to assist the battle against drug-resistant tuberculosis.

Rifampicin-Amlodipine Interaction: A Case Report of Hypertension Exacerbation

Introduction: Rifampicin, a first-line anti-tubercular therapy drug, is a strong inducer of hepatic cytochrome P450 (CYP). Amlodipine and metoprolol, two anti-hypertensives that are CYP substrates, have the potential to interact pharmacologically with rifampicin. Therefore, individuals with hypertension receiving rifampicin-based anti-tubercular therapy are at risk for worsening hypertension.&#x0D; Case Details: We report a case of a 63-year-old female patient, who developed accelerated hypertension after initiating rifampicin. Later, up to four antihypertensive drugs were administered as part of a gradual increase in dosage but did not successfully lower blood pressure to a desirable level. After clinical pharmacist intervention, Tab. Amlodipine+Metoprolol 5 mg+50 mg was discontinued and the blood pressure measurements gradually improved.&#x0D; Conclusion: We postulate that rifampicin diminished the therapeutic effect of amlodipine and metoprolol and hence recommend that prudent monitoring for worsening hypertension should be carried out in hypertensive patients with chronic kidney disease receiving anti-tubercular therapy.

The human proton pump inhibitors inhibit Mycobacterium tuberculosis rifampicin efflux and macrophage-induced rifampicin tolerance

Tuberculosis treatment requires months-long combination chemotherapy with multiple drugs, with shorter treatments leading to relapses. A major impediment to shortening treatment is that Mycobacterium tuberculosis becomes tolerant to the administered drugs, starting early after infection and within days of infecting macrophages. Multiple lines of evidence suggest that macrophage-induced drug tolerance is mediated by mycobacterial drug efflux pumps. Here, using assays to directly measure drug efflux, we find that M. tuberculosis transports the first-line antitubercular drug rifampicin through a proton gradient-dependent mechanism. We show that verapamil, a known efflux pump inhibitor, which inhibits macrophage-induced rifampicin tolerance, also inhibits M.tuberculosis rifampicin efflux. As with macrophage-induced tolerance, the calcium channel-inhibiting property of verapamil is not required for its inhibition of rifampicin efflux. By testing verapamil analogs, we show that verapamil directly inhibits M. tuberculosis drug efflux pumps through its human P-glycoprotein (PGP)-like inhibitory activity. Screening commonly used drugs with incidental PGPinhibitory activity, we find many inhibit rifampicin efflux, including the proton pump inhibitors (PPIs) such as omeprazole. Like verapamil, the PPIs inhibit macrophage-induced rifampicin tolerance as well as intramacrophage growth, which has also been linked to mycobacterial efflux pump activity. Our assays provide a facile screening platform for M. tuberculosis efflux pump inhibitors that inhibit invivo drug tolerance and growth.

Detection of katG and inhA Genes Mutation in Rifampicin-Resistant Mycobacterium Tuberculosis Using Line Probe Assay (LPA) In Kebbi, Nigeria

Elimination of tuberculosis remains a public health menace, due to multidrug resistant strains of Mycobacterium tuberculosis, that are resistant to the first-line anti-tubercular drugs. Consequently, detection of resistant strains depends on early diagnosis. Intervention of molecular techniques is essential to reduce mortality and morbidity rates. This study aimed to detect katG and inhA gene mutations among rifampicin resistant strain of Mycobacterium tuberculosis in Kebbi State. A cross-sectional study was conducted which covered all the five major health zones in Kebbi State. Two hundred and forty (240) acid fast bacilli confirmed sputum samples were recruited and subjected to Gene Xpert testing. Positive sputum samples were later subjected to Line Probe Assay technique. 14 sputum samples were resistant to rifampicin out of the 240 confirmed acid fast bacilli sputum samples while 226 were sensitive to rifampicin. Mutations were found at the frequency of 100% for katG gene (katG/S315T) in all the 14 rifampicin resistant samples (rpoB/S531L) at the different health zones in kebbi state using the line probe assay. The research has also detected inhA gene mutation at a frequency of 100% in all rifampicin resistant samples showing that mutation is associated with multi resistance to isoniazid and rifampicin. This study confirms that resistance due to katG and inhA mutation is a better surrogate of multidrug-resistant tuberculosis among TB patients in Kebbi State compared to the single-marker analysis. Hence, early molecular detection of rifampicin resistant strains will suffice in determining the management of multidrug resistant tuberculosis in Kebbi State.