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Journal of Pharmaceutical and... May 2019Tuberculosis is one of the top concerns in the world and acutely threatens human health. A new potent candidate regimen containing pyrazinamide (PZA), ethambutol (EMB),...
Simultaneous determination of the potent anti-tuberculosis regimen-Pyrazinamide, ethambutol, protionamide, clofazimine in beagle dog plasma using LC-MS/MS method coupled with 96-well format plate.
Tuberculosis is one of the top concerns in the world and acutely threatens human health. A new potent candidate regimen containing pyrazinamide (PZA), ethambutol (EMB), protionamide (PTO) and clofazimine (CFZ) was proposed by Parabolic Response Surface/Feedback System Control (FSC/PRS) system and showed excellent outcomes in vitro and vivo studies. Here, a convenient liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method was developed for the simultaneously determination of four compounds in beagle dog plasma. The plasma samples, 50 μL for each, were pretreated by methanol on 96-well format plates and a further dilution step was designed to reduce predictable matrix effect and lessen the burden of subsequent analysis. The chromatographic separation was achieved on an Agilent SB-Aq column (4.6 mm × 150 mm, 5 μm) at 30 °C by a gradient elution within 6 min. The mobile phase was a mixture of 0.2% formic acid-5 mM ammonium acetate aqueous solution (phase A) and 0.2% formic acid methanol (phase B) with a total flow rate of 1 mL/min. The 30% of post-column eluant was injected into mass spectrometer, equipped with electrospray ionization (ESI) source under positive mode and multiple-reaction monitoring (MRM). This quantification method was proved to be satisfied in selectivity, accuracy, precision, linearity (r > 0.998), recovery, matrix effect and stability. Under the specialized conditions, the calibration curves ranged from 20 to 5000 ng/mL for PZA, 1 to 500 ng/mL for EMB, 1 to 500 ng/mL for PTO, and 1 to 200 ng/mL for CFZ. The quantitative accuracy was further assessed under different degrees of hemolyses in detail. This method was proved to be robust and efficient, and successfully applied to the pharmacokinetic study of the new regimen in Beagle dogs.
Topics: Animals; Antitubercular Agents; Calibration; Chromatography, Liquid; Clofazimine; Dogs; Ethambutol; Prothionamide; Pyrazinamide; Reproducibility of Results; Tandem Mass Spectrometry
PubMed: 30784889
DOI: 10.1016/j.jpba.2019.02.006 -
BMC Bioinformatics Feb 2019It is possible to predict whether a tuberculosis (TB) patient will fail to respond to specific antibiotics by sequencing the genome of the infecting Mycobacterium...
BACKGROUND
It is possible to predict whether a tuberculosis (TB) patient will fail to respond to specific antibiotics by sequencing the genome of the infecting Mycobacterium tuberculosis (Mtb) and observing whether the pathogen carries specific mutations at drug-resistance sites. This advancement has led to the collation of TB databases such as PATRIC and ReSeqTB that possess both whole genome sequences and drug resistance phenotypes of infecting Mtb isolates. Bioinformatics tools have also been developed to predict drug resistance from whole genome sequencing (WGS) data. Here, we evaluate the performance of four popular tools (TBProfiler, MyKrobe, KvarQ, PhyResSE) with 6746 isolates compiled from publicly available databases, and subsequently identify highly probable phenotyping errors in the databases by genetically predicting the drug phenotypes using all four software.
RESULTS
Our results show that these bioinformatics tools generally perform well in predicting the resistance status for two key first-line agents (isoniazid, rifampicin), but the accuracy is lower for second-line injectables and fluoroquinolones. The error rates in the databases are also non-trivial, reaching as high as 31.1% for prothionamide, and that phenotypes from ReSeqTB are more susceptible to errors.
CONCLUSIONS
The good performance of the automated software for drug resistance prediction from TB WGS data shown in this study further substantiates the usefulness and promise of utilising genetic data to accurately profile TB drug resistance, thereby reducing misdiagnoses arising from error-prone culture-based drug susceptibility testing.
Topics: Algorithms; Antitubercular Agents; Benchmarking; Calibration; Databases, Genetic; Drug Resistance, Bacterial; Genomics; Humans; Microbial Sensitivity Tests; Mycobacterium tuberculosis; Sensitivity and Specificity; Software; Tuberculosis
PubMed: 30736750
DOI: 10.1186/s12859-019-2658-z -
Clinical Microbiology and Infection :... Aug 2019Prothionamide, a structural analogue of isoniazid, is used mainly for treating multidrug-resistant tuberculosis (MDR-TB). Both drugs have a common target InhA, so...
OBJECTIVES
Prothionamide, a structural analogue of isoniazid, is used mainly for treating multidrug-resistant tuberculosis (MDR-TB). Both drugs have a common target InhA, so prothionamide can be ineffective against isoniazid-resistant (INH) Mycobacterium tuberculosis. We aimed to investigate the prevalence of mutations in katG, ethA, ndh, ethR, mshA, inhA and/or its promoter associated with independent resistance and cross-resistance to INH and/or prothionamide-resistant (PTO) M. tuberculosis isolates.
METHODS
We sequenced the above genes in 206 M. tuberculosis isolates with susceptibility testing against ten drugs.
RESULTS
Of the 173 INH PTO isolates, 170 (98.3%) harboured mutations in katG, 111 (64.2%) in ethA, 58 (33.5%) in inhA or its promoter, 5 (2.9%) in ndh, 3 (1.7 %) in ethR and 2 (1.2%) in mshA. Among the 18 INH PTO isolates, mutations in katG were found in all of them; one had a mutation in the inhA promoter and another in ndh. Of the five INH PTO isolates, four showed mutations in ethA and two in the inhA promoter. Notably, 55 novel non-synonymous mutations were found in them and 20.2% of the PTOM. tuberculosis isolates harboured no known mutations.
CONCLUSIONS
This is the first report to investigate cross-resistance between INH and/or PTO isolates. Among INH (94.4% MDR-TB) M. tuberculosis isolates, the high diversity of mutations for independent resistance and cross-resistance with prothionamide highlight the importance of both phenotypic susceptibility and genotypic diagnosis when using it to treat patients with INH-TB. The high proportion (one-fifth) of PTOM. tuberculosis isolates showed no known mutation related to PTO genes, so uncovered resistance mechanism(s) of prothionamide exist.
Topics: Antitubercular Agents; Bacterial Proteins; Drug Resistance, Multiple, Bacterial; Genotype; Humans; Isoniazid; Microbial Sensitivity Tests; Mutation; Mycobacterium tuberculosis; Promoter Regions, Genetic; Prothionamide; Sequence Analysis, DNA; Tuberculosis, Multidrug-Resistant
PubMed: 30583053
DOI: 10.1016/j.cmi.2018.12.008 -
Drug Metabolism Reviews Feb 2019Cachexia not only has a dramatically harmful impact on a patient's life, but also a poor response to therapeutic agents. The purpose of the present review is to provide...
Cachexia not only has a dramatically harmful impact on a patient's life, but also a poor response to therapeutic agents. The purpose of the present review is to provide updated information concerning the pharmacokinetic aspects of drugs used to treat cardiopulmonary cachexia in patients with no signs of hepatic or renal pathology. A systematic search of PubMed, the Cochrane Central Register of Control Trials, Science Direct, and Clinical Trials Registry (ClinicalTrials.gov), encompassing the period between 2000 and 2017, was conducted in accordance to PRISMA guidelines. Seven studies were identified. Collectively, these studies included a total of 196 individuals (19 healthy subjects and 177 diseased patients). This data review found no differences in bisoprolol and prothionamide absorption in cachectic patients with chronic heart failure and tuberculosis, but higher absorption of oflaxocin in the same set of patients was observed. The distribution of bisoprolol, prothionmaide, ceftazidime, and cefipirome was reduced in cardiopulmonary cachexia patients. Hepatic clearance of rifampin was equivalent in cachectic and non-cachectic patients that had normal hepatic function. Similarly in cardiopulmonary cachexia patients, renal clearance of ceftazidime was reduced by 19% but no significant differences in bisorpolol and prothionamide clearance were observed. In the case of cefipirome, both renal clearance and creatinine clearance were higher in cachectic patients with cystic fibrosis. From the limited evidence available, the main drug pharmacokinetic changes seen in cardiopulmonary cachexia patients were a reduction in the volume of distribution and impairment of clearance.
Topics: Cachexia; Chronic Disease; Clinical Trials as Topic; Heart; Heart Failure; Humans; Kidney; Liver; Pharmaceutical Preparations
PubMed: 30449195
DOI: 10.1080/03602532.2018.1508226 -
Tuberculosis and Respiratory Diseases Apr 2019The purpose of this study was to analyze the relationship between the gene mutation patterns by the GenoType MTBDR (MTBDR) assay and the phenotypic drug susceptibility...
BACKGROUND
The purpose of this study was to analyze the relationship between the gene mutation patterns by the GenoType MTBDR (MTBDR) assay and the phenotypic drug susceptibility test (pDST) results of isoniazid (INH) and prothionamide (Pto).
METHODS
A total of 206 patients whose MTBDR assay results revealed or mutations were enrolled in the study. The pDST results were compared to mutation patterns on the MTBDR assay.
RESULTS
The and mutations were identified in 68.0% and 35.0% of patients, respectively. Among the 134 isolated mutations, three (2.2%), 127 (94.8%) and 11 (8.2%) were phenotypically resistant to low-level INH, high-level INH, and Pto, respectively. Among the 66 isolated mutations, 34 (51.5%), 18 (27.3%) and 21 (31.8%) were phenotypically resistant to low-level INH, high-level INH, and Pto, respectively. Of the 34 phenotypic Pto resistant isolates, 21 (61.8%), 11 (32.4%), and two (5.9%) had , , and both gene mutations.
CONCLUSION
It is noted that Pto may still be selected as one of the appropriate multidrug-resistant tuberculosis regimen, although mutation is detected by the MTBDR assay until pDST confirms a Pto resistance. The reporting of detailed mutation patterns of the MTBDR assay may be important for clinical practice, rather than simply presenting resistance or susceptibility test results.
PubMed: 30302956
DOI: 10.4046/trd.2018.0027 -
BMJ Open Oct 2018Individualised treatment through therapeutic drug monitoring (TDM) may improve tuberculosis (TB) treatment outcomes but is not routinely implemented. Prospective...
Plasma concentrations of second-line antituberculosis drugs in relation to minimum inhibitory concentrations in multidrug-resistant tuberculosis patients in China: a study protocol of a prospective observational cohort study.
INTRODUCTION
Individualised treatment through therapeutic drug monitoring (TDM) may improve tuberculosis (TB) treatment outcomes but is not routinely implemented. Prospective clinical studies of drug exposure and minimum inhibitory concentrations (MICs) in multidrug-resistant TB (MDR-TB) are scarce. This translational study aims to characterise the area under the concentration-time curve of individual MDR-TB drugs, divided by the MIC for isolates, to explore associations with markers of treatment progress and to develop useful strategies for clinical implementation of TDM in MDR-TB.
METHODS AND ANALYSIS
Adult patients with pulmonary MDR-TB treated in Xiamen, China, are included. Plasma samples for measure of drug exposure are obtained at 0, 1, 2, 4, 6, 8 and 10 hours after drug intake at week 2 and at 0, 4 and 6 hours during weeks 4 and 8. Sputum samples for evaluating time to culture positivity and MIC determination are collected at days 0, 2 and 7 and at weeks 2, 4, 8 and 12 after treatment initiation. Disease severity are assessed with a clinical scoring tool (TBscore II) and quality of life evaluated using EQ-5D-5L. Drug concentrations of pyrazinamide, ethambutol, levofloxacin, moxifloxacin, cycloserine, prothionamide and para-aminosalicylate are measured by liquid chromatography tandem-mass spectrometry and the levels of amikacin measured by immunoassay. Dried blood spot on filter paper, to facilitate blood sampling for analysis of drug concentrations, is also evaluated. The MICs of the drugs listed above are determined using custom-made broth microdilution plates and MYCOTB plates with Middlebrook 7H9 media. MIC determination of pyrazinamide is performed in BACTEC MGIT 960.
ETHICS AND DISSEMINATION
This study has been approved by the ethical review boards of Karolinska Institutet, Sweden and Fudan University, China. Informed written consent is given by participants. The study results will be submitted to a peer-reviewed journal.
TRIAL REGISTRATION NUMBER
NCT02816931; Pre-results.
Topics: Adult; Female; Humans; Male; Antitubercular Agents; China; Cohort Studies; Drug Monitoring; Microbial Sensitivity Tests; Mycobacterium tuberculosis; Prospective Studies; Serum Bactericidal Test; Tuberculosis, Multidrug-Resistant; Observational Studies as Topic
PubMed: 30287613
DOI: 10.1136/bmjopen-2018-023899 -
Antimicrobial Agents and Chemotherapy Dec 2018Short-course regimens for multidrug-resistant tuberculosis (MDR-TB) are urgently needed. Limited data suggest that the new drug bedaquiline (BDQ) may have the potential...
Short-course regimens for multidrug-resistant tuberculosis (MDR-TB) are urgently needed. Limited data suggest that the new drug bedaquiline (BDQ) may have the potential to shorten MDR-TB treatment to less than 6 months when used in conjunction with standard anti-TB drugs. However, the feasibility of BDQ in shortening MDR-TB treatment duration remains to be established. Mathematical modeling provides a platform to investigate different treatment regimens and predict their efficacy. We developed a mathematical model to capture the immune response to TB inside a human host environment. This model was then combined with a pharmacokinetic-pharmacodynamic model to simulate various short-course BDQ-containing regimens. Our modeling suggests that BDQ could reduce MDR-TB treatment duration to just 18 weeks (4 months) while still maintaining a very high treatment success rate (100% for daily BDQ for 2 weeks, or 95% for daily BDQ for 1 week during the intensive phase). The estimated time to bacterial clearance of these regimens ranges from 27 to 33 days. Our findings provide the justification for empirical evaluation of short-course BDQ-containing regimens. If short-course BDQ-containing regimens are found to improve outcomes, then we anticipate clear cost savings and a subsequent improvement in the efficiency of national TB programs.
Topics: Antitubercular Agents; Clofazimine; Colony Count, Microbial; Computer Simulation; Diarylquinolines; Dose-Response Relationship, Drug; Drug Dosage Calculations; Drug Resistance, Bacterial; Drug Therapy, Combination; Ethambutol; Host-Pathogen Interactions; Humans; Immunity, Innate; Isoniazid; Kanamycin; Macrophages; Microbial Sensitivity Tests; Models, Statistical; Moxifloxacin; Mycobacterium tuberculosis; Ofloxacin; Prothionamide; Pyrazinamide; Time Factors; Tuberculosis, Multidrug-Resistant
PubMed: 30249697
DOI: 10.1128/AAC.01487-18 -
Internal Medicine Journal Mar 2019Reports from resource-poor countries have associated thionamide- and para-aminosalicylate sodium (PAS)-based treatment of multi-drug-resistant tuberculosis (MDR-TB) with...
BACKGROUND
Reports from resource-poor countries have associated thionamide- and para-aminosalicylate sodium (PAS)-based treatment of multi-drug-resistant tuberculosis (MDR-TB) with the development of hypothyroidism.
AIM
To identify predictors and assess the cumulative proportions of hypothyroidism in patients treated for MDR-TB with these agents in Australia.
METHODS
Retrospective multicentre study of MDR-TB patients from five academic centres covering tuberculosis (TB) services in Victoria, Australia. Patients were identified using each centre's pharmacy department and cross checked with the Victorian Tuberculosis Program. Hypothyroidism was categorised as subclinical if the thyroid-stimulating hormone was elevated and as overt if free thyroxine (fT4) was additionally reduced on two separate occasions. Our main outcome measured was the cumulative proportion of hypothyroidism (at 5 years from treatment initiation).
RESULTS
Of the 29 cases available for analysis, the cumulative proportion of hypothyroidism at 5 years was 37% (95% confidence interval (CI): 0-57.8%). Eight of the nine affected cases developed hypothyroidism within the first 12 months of treatment. Hypothyroidism was marginally (P = 0.06) associated with higher prothionamide/PAS dosing and was reversible with cessation of the anti-tuberculosis medication.
CONCLUSIONS
Prothionamide/PAS treatment-associated hypothyroidism is common in MDR-TB patients in Australia, emphasising the importance of regular thyroid function monitoring during this treatment. Thyroid hormone replacement, if initiated, may not need to be continued after MDR-TB treatment is completed.
Topics: Adult; Antitubercular Agents; Female; Humans; Hypothyroidism; Male; Middle Aged; Proportional Hazards Models; Retrospective Studies; Tuberculosis, Multidrug-Resistant; Victoria; Young Adult
PubMed: 30151969
DOI: 10.1111/imj.14085 -
Antimicrobial Agents and Chemotherapy Sep 2018The substrate potentials of antituberculosis drugs on solute carrier (SLC) transporters are not well characterized to date, despite a well-established understanding of...
The substrate potentials of antituberculosis drugs on solute carrier (SLC) transporters are not well characterized to date, despite a well-established understanding of their drug dispositions and pharmacokinetics. In this study, we investigated comprehensively the substrate potentials of the 22 currently available antituberculosis drugs for SLC family transporter-mediated uptake, using oocytes and stably transfected HEK-293 cells The result suggested that ethambutol, isoniazid, amoxicillin, and prothionamide act as novel substrates for the SLC transporters. In addition, in the presence of representative transporter inhibitors, the uptake of the antituberculosis drugs was markedly decreased compared with the uptake in the absence of inhibitor, suggesting involvement of the corresponding transporters. A cellular uptake study was performed, and the values of ethambutol were found to be 526.1 ± 15.6, 212.0 ± 20.1, 336.8 ± 20.1, and 455.0 ± 28 μM for organic cation transporter 1 (OCT1), OCT2, OCTN1, and OCTN2, respectively. Similarly, the of prothionamide was 805.8 ± 23.4 μM for OCT1, while the values of isoniazid and amoxicillin for organic anion transporter 3 (OAT3) were 233.7 ± 14.1 and 161.4 ± 10.6 μM, respectively. The estimated drug-drug interaction indexes from transporter inhibition kinetics for verapamil, probenecid, and ibuprofen against ethambutol, prothionamide, isoniazid, and amoxicillin were found to show potential for clinical drug interactions. In conclusion, this is the first study that demonstrated 22 antituberculosis drug interactions with transporters. This study will be helpful for mechanistic understanding of the disposition, drug-drug interactions, and pharmacokinetics of these antituberculosis drugs.
PubMed: 30012768
DOI: 10.1128/AAC.00512-18 -
Infection and Drug Resistance 2018Ethionamide (ETA) and prothionamide (PRO) are interchangeably used in tuberculosis (TB) chemotherapy regimens. Subtle discrepancies between biochemical and genetic...
Ethionamide (ETA) and prothionamide (PRO) are interchangeably used in tuberculosis (TB) chemotherapy regimens. Subtle discrepancies between biochemical and genetic information on the modes of sensitivity and resistance of isoniazid (INH) and ETA warrants further studies. We report a new mutation - EthA - in Bacillus Calmette-Guérin that corresponds with co-resistance to both PRO and ETA, which to the best of our knowledge has not been reported before. Our findings suggest that mutation EthA could be used as a marker site for testing PRO and ETA cross-resistance.
PubMed: 29942141
DOI: 10.2147/IDR.S163965