Anti-TB drug concentrations and drug-associated toxicities among TB/HIV-coinfected patients

New thiazolyl-isoxazole derivatives as potential anti-infective agents: design, synthesis, in vitro and in silico antimicrobial efficacy

Antimicrobial resistance threatens the efficacious prevention and treatment of infectious diseases caused by microorganisms. To combat microbial infections, the need for new drug candidates is essential. In this context, the design, synthesis, antimicrobial screening, and in silico study of a new series of 5-aryl-3-(2-arylthiazol-4-yl)isoxazole (9a-t) have been reported. The structure of new compounds was confirmed by spectrometric methods. Compounds 9a-t were evaluated for in vitro antitubercular and antimicrobial activity. Against M. tuberculosis H37Rv, fourteen compounds showed good to excellent antitubercular activity with MIC 2.01-9.80 µM. Compounds 9a, 9b, and 9r showed four-fold more activity than the reference drug isoniazid. Nine compounds, 9a, 9b, 9d, 9e, 9i, 9q, 9r, 9s, and 9t, showed good antibacterial activity against E. coli with MIC 7.8-15.62 µg/mL. Against A. niger, four compounds showed good activity with MIC 31.25 µg/mL. Against C. albicans, all twenty compounds reported excellent to good activity with MIC 7.8-31.25 µg/mL. Compounds 9c-e, 9g-j, and 9q-t showed comparable activity concerning the reference drug fluconazole. The compounds 9a-t were screened for cytotoxicity against 3t3l1 cell lines and found to be less or non-cytotoxic. The in silico study exposed that these compounds displayed high affinity towards the M. tuberculosis targets PanK, DprE1, DHFR, PknA, KasA, and Pks13, and C. albicans targets NMT, CYP51, and CS. The compound 9r was evaluated for structural dynamics and molecular dynamics simulations. The potent antitubercular and antimicrobial activity of 5-aryl-3-(2-arylthiazol-4-yl)isoxazole (9a-t) derivatives has recommended that these compounds could assist in treating microbial infections.Communicated by Ramaswamy H. Sarma.

Design, Synthesis, and Evaluation of Novel Δ2-Thiazolino 2-Pyridone Derivatives That Potentiate Isoniazid Activity in an Isoniazid-Resistant Mycobacterium tuberculosis Mutant

Mycobacterium tuberculosis (Mtb) drug resistance poses an alarming threat to global tuberculosis control. We previously reported that C10, a ring-fused thiazolo-2-pyridone, inhibits Mtb respiration, blocks biofilm formation, and restores the activity of the antibiotic isoniazid (INH) in INH-resistant Mtb isolates. This discovery revealed a new strategy to address INH resistance. Expanding upon this strategy, we identified C10 analogues with improved potency and drug-like properties. By exploring three heterocycle spacers (oxadiazole, 1,2,3-triazole, and isoxazole) on the ring-fused thiazolo-2-pyridone scaffold, we identified two novel isoxazoles, 17h and 17j. 17h and 17j inhibited Mtb respiration and biofilm formation more potently with a broader therapeutic window, were better potentiators of INH-mediated inhibition of an INH-resistant Mtb mutant, and more effectively inhibited intracellular Mtb replication than C10. The (-)17j enantiomer showed further enhanced activity compared to its enantiomer and the 17j racemic mixture. Our potent second-generation C10 analogues offer promise for therapeutic development against drug-resistant Mtb.

Incidence and Temporal Trend of Antituberculosis Drug-Induced Liver Injury: A Systematic Review and Meta-Analysis

Methods

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards were followed, and the protocol was registered in PROSPERO (CRD42020200077). Five electronic databases were searched to identify eligible studies published between 1990 and 2022. Search terms included anti-TB treatment and drug-induced liver injury. Studies that reported the incidence of ATLI or provided sufficient data to calculate the incidence of ATLI were included, and duplicate studies were excluded. Meta-analysis was conducted on the basis of logit-transformed metrics for the incidence of ATLI with 95% confidence intervals (CIs), followed by a predefined subgroup meta-analysis. Temporal trend analyses were performed to describe the change in pooled incidence over time. A random effects metaregression was conducted to explore the source of heterogeneity. All statistical analyses were carried out using R 4.0.1.

Results

A total of 160 studies from 156 records with 116147 patients were included in the meta-analysis. Based on the random effects model, the pooled incidence of ATLI was 11.50% (95% CI: 10.10%–12.97%) and showed an upward trend over time (P < 0.001). Patients who received first-line anti-TB drugs, patients in South America, and patients with hepatitis B and C virus coinfection had a higher incidence of ATLI (13.66%, 18.16%, and 39.19%, respectively). Sensitivity analyses also confirmed this robust incidence after the exclusion of some studies. The metaregression showed that different anti-TB regimens and geographical regions were important explanatory factors of the heterogeneity between studies.

Conclusions

The present systematic review provided a basis for estimating the incidence of ATLI worldwide, which varied among patients with different anti-TB regimens in different geographical regions and with different coinfections and had an upward trend. Regular liver function monitoring is imperative for patient safety during the anti-TB treatment course.

Semi-Automated Therapeutic Drug Monitoring as a Pillar toward Personalized Medicine for Tuberculosis Management

Standard tuberculosis (TB) management has failed to control the growing number of drug-resistant TB cases worldwide. Therefore, innovative approaches are required to eradicate TB. Model-informed precision dosing and therapeutic drug monitoring (TDM) have become promising tools for adjusting anti-TB drug doses corresponding with individual pharmacokinetic profiles. These are crucial to improving the treatment outcome of the patients, particularly for those with complex comorbidity and a high risk of treatment failure. Despite the actual benefits of TDM at the bedside, conventional TDM encounters several hurdles related to laborious, time-consuming, and costly processes. Herein, we review the current practice of TDM and discuss the main obstacles that impede it from successful clinical implementation. Moreover, we propose a semi-automated TDM approach to further enhance precision medicine for TB management.

Host bioenergetic parameters reveal cytotoxicity of anti-tuberculosis drugs undetected using conventional viability assays

High attrition rates in tuberculosis (TB) drug development have been largely attributed to safety, which is likely due to the use of endpoint assays measuring cell viability to detect drug cytotoxicity. In drug development for cancer, metabolic, and neurological disorders and for antibiotics, cytotoxicity is increasingly being assessed using extracellular flux (XF) analysis, which measures cellular bioenergetic metabolism in real time. Here, we adopt the XF platform to investigate the cytotoxicity of drugs currently used in TB treatment on the bioenergetic metabolism of HepG2 cells, THP-1 macrophages, and human monocyte-derived macrophages (hMDMs). We found that the XF analysis reveals earlier drug-induced effects on the cells’ bioenergetic metabolism prior to cell death, measured by conventional viability assays. Furthermore, each cell type has a distinct response to drug treatment, suggesting that more than one cell type should be considered to examine cytotoxicity in TB drug development. Interestingly, chemically unrelated drugs with different modes of action on Mycobacterium tuberculosis have similar effects on the bioenergetic parameters of the cells, thus discouraging the prediction of potential cytotoxicity based on chemical structure and mode of action of new chemical entities. The clustering of the drug-induced effects on the hMDM bioenergetic parameters are reflected in the clustering of the effects of the drugs on cytokine production in hMDMs, demonstrating concurrence between the effects of the drugs on the metabolism and functioning of the macrophages. These findings can be used as a benchmark to establish XF analysis as a new tool to assay cytotoxicity in TB drug development.

Pharmacokinetics, SAfety/tolerability, and EFficacy of high-dose RIFampicin in tuberculosis-HIV co-infected patients on efavirenz- or dolutegravir-based antiretroviral therapy: study protocol for an open-label, phase II clinical trial (SAEFRIF)

BACKGROUND

Tuberculosis (TB) is a significant public health problem that causes substantial morbidity and mortality. Current first-line anti-TB chemotherapy, although very effective, has limitations including long-treatment duration with a possibility of non-adherence, drug interactions, and toxicities. Dose escalation of rifampicin, an important drug within the regimen, has been proposed as a potential route to higher treatment efficacy with shorter duration and some studies have suggested that dose escalation is safe; however, these have almost entirely been conducted among human immunodeficiency (HIV)-negative TB patients. TB-HIV co-infected patients on antiretroviral therapy (ART) are at increased risk of drug-drug interactions and drug-related toxicities. This study aims to determine the safety of higher doses of rifampicin and its effect on the pharmacokinetics of efavirenz (EFV) and dolutegravir (DTG) in TB-HIV co-infected patients.

METHODS

This study is a randomized, open-label, phase IIb clinical trial among TB-HIV infected adult outpatients attending an HIV clinic in Kampala, Uganda. Patients newly diagnosed with TB will be randomized to either standard-dose or high-dose rifampicin (35 mg/kg) alongside standard TB treatment. ART-naïve patients will be randomly assigned to first-line ART regimens (DTG or EFV). Those who are already on ART (DTG or EFV) at enrollment will be continued on the same ART regimen but with dose adjustment of DTG to twice daily dosing. Participants will be followed every 2 weeks with assessment for toxicities at each visit and measurement of drug concentrations at week 6. At the end of intensive-phase therapy (8 weeks), all participants will be initiated on continuation-phase treatment using standard-dose rifampicin and isoniazid.

DISCUSSION

This study should avail us with evidence about the effect of higher doses of rifampicin on the pharmacokinetics of EFV and DTG among TB-HIV co-infected patients. The trial should also help us to understand safety concerns of high-dose rifampicin among this vulnerable cohort.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT03982277. Registered retrospectively on 11 June 2019.

Delayed Sputum Culture Conversion in Tuberculosis-Human Immunodeficiency Virus-Coinfected Patients With Low Isoniazid and Rifampicin Concentrations

Background

The relationship between concentrations of antituberculosis drugs, sputum culture conversion, and treatment outcome remains unclear. We sought to determine the association between antituberculosis drug concentrations and sputum conversion among patients coinfected with tuberculosis and human immunodeficiency virus (HIV) and receiving first-line antituberculosis drugs.

Methods

We enrolled HIV-infected Ugandans with pulmonary tuberculosis. Estimation of first-line antituberculosis drug concentrations was performed 1, 2, and 4 hours after drug intake at 2, 8, and 24 weeks of tuberculosis treatment. Serial sputum cultures were performed at each visit. Time-to-event analysis was used to determine factors associated with sputum culture conversion.

Results

We enrolled 268 HIV-infected patients. Patients with low isoniazid and rifampicin concentrations were less likely to have sputum culture conversion before the end of tuberculosis treatment (hazard ratio, 0.54; 95% confidence interval, .37-.77; P = .001) or by the end of follow-up (0.61; .44-.85; P = .003). Patients in the highest quartile for area under the rifampicin and isoniazid concentration-time curves for were twice as likely to experience sputum conversion than those in the lowest quartile. Rifampicin and isoniazid concentrations below the thresholds and weight <55 kg were both risk factors for unfavorable tuberculosis treatment outcomes. Only 4.4% of the participants had treatment failure.

Conclusion

Although low antituberculosis drug concentrations did not translate to a high proportion of patients with treatment failure, the association between low concentrations of rifampicin and isoniazid and delayed culture conversion may have implications for tuberculosis transmission. Clinical Trials Registration: NCT01782950.

Toxicity associated with tuberculosis chemotherapy in the REMoxTB study

BACKGROUND

The incidence and severity of tuberculosis chemotherapy toxicity is poorly characterised. We used data available from patients in the REMoxTB trial to provide an assessment of the risks associated with the standard regimen and two experimental regimens containing moxifloxacin.

METHODS

All grade 3 & 4 adverse events (AEs) and their relationship to treatment for patients who had taken at least one dose of therapy in the REMoxTB clinical trial were recorded. Univariable logistic regression was used to test the relationship of baseline characteristics to the incidence of grade 3 & 4 AEs and significant characteristics (p < 0.10) were incorporated into a multivariable model. The timing of AEs during therapy was analysed in standard therapy and the experimental arms. Logistic regression was used to investigate the relationship between AEs (total and related-only) and microbiological cure on treatment.

RESULTS

In the standard therapy arm 57 (8.9%) of 639 patients experienced ≥1 related AEs with 80 of the total 113 related events (70.8%) occurring in the intensive phase of treatment. Both four-month experimental arms ("isoniazid arm" with moxifloxacin substituted for ethambutol & "ethambutol arm" with moxifloxacin substituted for isoniazid) had a lower total of related grade 3 & 4 AEs than standard therapy (63 & 65 vs 113 AEs). Female gender (adjOR 1.97, 95% CI 0.91-1.83) and HIV-positive status (adjOR 3.33, 95% CI 1.55-7.14) were significantly associated with experiencing ≥1 related AE (p < 0.05) on standard therapy. The most common adverse events on standard therapy related to hepatobiliary, musculoskeletal and metabolic disorders. Patients who experienced ≥1 related AE were more likely to fail treatment or relapse (adjOR 3.11, 95% CI 1.59-6.10, p < 0.001).

CONCLUSIONS

Most AEs considered related to standard therapy occurred in the intensive phase of treatment with female patients and HIV-positive patients demonstrating a significantly higher risk of AEs during treatment. Almost a tenth of standard therapy patients had a significant side effect, whereas both experimental arms recorded a lower incidence of toxicity. That patients with one or more AE are more likely to fail treatment suggests that treatment outcomes could be improved by identifying such patients through targeted monitoring.

Elevated Aspergillus-specific antibody levels among HIV infected Ugandans with pulmonary tuberculosis

BACKGROUND

The incidence of tuberculosis (TB) is high among human immunodeficiency virus (HIV) infected Ugandans. Recent evidence suggests that Chronic Pulmonary Aspergillosis and Aspergillus sensitisation might be responsible for significant mortality in patients treated for tuberculosis in Uganda.

METHODS

We retrieved and tested paired serum aliquots for 101 HIV-TB co-infected patients at the beginning and week 24 of TB treatment. We tested samples for Aspergillus-specific immunoglobulin G (IgG) and immunoglobulin E (IgE) using ImmunoCAP®; and Aspergillus-specific IgG and total serum IgE using Immulite® immunoassays. We compared antibody levels between baseline and week 24, relating them to selected baseline characteristics.

RESULTS

10% of the patients had elevated Aspergillus-specific IgE (Aspergillus sensitization) and Aspergillus-specific IgG antibodies were elevated in 9% of the patients at the end of TB treatment. There was a significant fall in the Aspergillus-specific IgG antibody levels between baseline and week 24 (P = 0.02). Patients with cluster of differentiation 4 (CD4) T-cell count <100 cells/μl and those who were not on anti-retroviral therapy at baseline had more elevated Aspergillus-specific IgG antibodies (P = 0.01, P = 0.03). The ImmunoCAP® Aspergillus-specific IgG antibody titres were higher at week 24 than baseline with more positives at week 24; even though the difference in means was small. However, this difference was statistically significant (P = 0.02). Pulmonary infiltrates were the commonest x-ray abnormality and only 5% of the patients had pulmonary cavities on chest x-ray at week 24.

CONCLUSION

These results suggest that Aspergillus infection may complicate active pulmonary TB and further studies including fungal culture and thoracic imaging may now be indicated to measure the prevalence of pulmonary aspergillosis complicating tuberculosis.

TRIAL REGISTRATION

The SOUTH trial was registered prospectively. ClinicalTrials.gov Identifier: NCT01782950 ; Registration date: 4th February 2013; Last verified: 13th April 2015.