Time for a change: considering regimen changes in analyses of observational drug-resistant TB treatment cohort data

2020 ◽  
Vol 24 (11) ◽  
pp. 1151-1155
Author(s):  
M. F. Franke ◽  
C. D. Mitnick

Randomized clinical trials represent the gold standard in therapeutic research. Nevertheless, observational cohorts of patients treated for multidrug-resistant TB (MDR-TB) or rifampin-resistant TB (RR-TB) also play an important role in generating evidence to guide drug-resistant TB care. Generally, summary exposure classifications (e.g., ‘ever vs. never´, ‘exposed at baseline´) have been used to characterize drug exposure in the absence of detailed longitudinal data on MDR-TB regimen changes. These summary classifications, along with an absence of data on covariates that change throughout the course of treatment, constrain researchers´ ability to answer the most relevant questions while accounting for known biases. In this paper, we highlight the importance of regimen changes in improving inference from observational studies of longer MDR-TB treatment regimens, and offer an overview of the data and analytic strategies required to do so.

2014 ◽  
Vol 45 (4) ◽  
pp. 1081-1088 ◽  
Author(s):  
Gunar Günther ◽  
Gabriela B. Gomez ◽  
Christoph Lange ◽  
Stephan Rupert ◽  
Frank van Leth

Data on availability and cost of anti-tuberculosis (TB) drugs in relation to affordability at national level are scarce.We performed a cross-sectional study on availability and cost of anti-TB drugs at major TB-reference centres in 37 European countries. Costs of standardised treatment regimens used for pan-sensitive TB, multidrug-resistant (MDR) TB, pre-extensively drug-resistant (XDR) TB, and XDR-TB were compared using a purchasing power analysis. Affordability was evaluated in relation to monthly national gross domestic products per capita (GDP).At least one second-line injectable and either moxifloxacin or levofloxacin were available in all countries. Linezolid and clofazimine were available in 79% and 46% of the countries, respectively. Drug cost for XDR-TB was three-times more expensive than those for MDR-TB. The average price of treatment for pan-sensitive TB represented a maximum of 8.5% of the monthly GDP across countries, while for standard MDR-TB treatment this was <30% in only six countries and more than 100% in four countries. Treatment of XDR-TB represented more than 100% of a month's GDP in all countries where the regimen was available.High cost and limited availability of drugs for treatment of drug-resistant TB, particularly beyond resistance to first-line drugs, are a major impediment to successful TB control in Europe.


Author(s):  
N. Yu. Nikolenko ◽  
D. А. Kudlay ◽  
N. P. Doktorova

Treatment of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis (TB) is a current problem worldwide. Currently, special attention is paid to the possibility of using new high-cost chemotherapy regimens in the treatment of MDR/XDR-TB. Numerous studies have shown that, from a clinical point of view, the effectiveness of MDR/XDR-TB therapy increases with the inclusion of bedaquiline, delamanid, linezolid, fluoroquinolones (moxifloxacin, levofloxacin), and pretomanid. At the same time, there is an assumption that the use of new and repurposed anti-tuberculosis drugs (ATDs) may be associated with an increase in overall costs. This paper demonstrates the potential of pharmacoepidemiology and pharmacoeconomics to evaluate the widespread introduction of new anti-tuberculosis drugs (ATDs), taking into account all the typical features of MDR/XDR-TB therapy. The authors analyzed studies of pharmacoeconomic feasibility of using expensive drugs in treatment regimens of pulmonary tuberculosis patients with MDR/XDR pathogen. It was shown that the use of chemotherapy regimens containing new high-cost and highly effective drugs (moxifloxacin, linizolid, and bedaquiline) in rational combinations with other drugs of the basic and reserve series, selected concerning drug resistance of the pathogen, is associated with a significant economic effect. From the applicability of pharmacoeconomic analysis point of view, the introduction of short-term MDR-TB treatment regimens is also a promising direction in phthisiology. The key link to achieve effective MDR/XDR-TB treatment is the use of new drugs. Considering the specificity of pharmacoeconomic analysis in phthisiology and results of existing clinical and economic studies, the authors have formed recommendations aimed at a more complete realization of pharmacoeconomic analysis potential in MDR- and XDR-TB treatment.


2019 ◽  
Vol 23 (10) ◽  
pp. 1050-1054
Author(s):  
L. Guglielmetti ◽  
J. Jaffré ◽  
C. Bernard ◽  
F. Brossier ◽  
N. El Helali ◽  
...  

SETTING: The World Health Organization (WHO) recommends that multidrug-resistant tuberculosis (MDR-TB) treatment should be managed in collaboration with multidisciplinary advisory committees (consilia). A formal national Consilium has been established in France since 2005 to provide a centralised advisory service for clinicians managing MDR-TB and extensively drug-resistant (XDR-TB) cases.OBJECTIVE: Review the activity of the French TB Consilium since its establishment.DESIGN: Retrospective description and analysis of the activity of the French TB Consilium.RESULTS: Between 2005 and 2016, 786 TB cases or contacts of TB cases were presented at the French TB Consilium, including respectively 42% and 79% of all the MDR-TB and XDR-TB cases notified in France during this period. Treatment regimens including bedaquiline and/or delamanid were recommended for 42% of the cases presented at the French TB Consilium since 2009. Patients were more likely to be presented at the French TB Consilium if they were born in the WHO Europe Region, had XDR-TB, were diagnosed in the Paris region, or had resistance to additional drugs than those defining XDR-TB.CONCLUSION: The French TB Consilium helped supervise appropriate management of MDR/XDR-TB cases and facilitated implementation of new drugs for MDR/XDR-TB treatment.


PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248846
Author(s):  
Win Min Han ◽  
Wiriya Mahikul ◽  
Thomas Pouplin ◽  
Saranath Lawpoolsri ◽  
Lisa J. White ◽  
...  

This study aimed to predict the impacts of shorter duration treatment regimens for multidrug-resistant tuberculosis (MDR-TB) on both MDR-TB percentage among new cases and overall MDR-TB cases in the WHO Southeast Asia Region. A deterministic compartmental model was constructed to describe both the transmission of TB and the MDR-TB situation in the Southeast Asia region. The population-level impacts of short-course treatment regimens were compared with the impacts of conventional regimens. Multi-way analysis was used to evaluate the impact by varying programmatic factors (eligibility for short-course MDR-TB treatment, treatment initiation, and drug susceptibility test (DST) coverage). The model predicted that overall TB incidence will be reduced from 246 (95% credible intervals (CrI), 221–275) per 100,000 population in 2020 to 239 (95% CrI, 215–267) per 100,000 population in 2035, with a modest reduction of 2.8% (95% CrI, 2.7%–2.9%). Despite the slight reduction in overall TB infections, the model predicted that the MDR-TB percentage among newly notified TB infections will remain steady, with 2.4% (95% CrI, 2.1–2.9) in 2020 and 2.5% (95% CrI, 2.3–3.1) in 2035, using conventional MDR-TB treatment. With the introduction of short-course regimens to treat MDR-TB, the development of resistance can be slowed by 38.6% (95% confidence intervals (CI), 35.9–41.3) reduction in MDR-TB case number, and 37.6% (95% CI, 34.9–40.3) reduction in MDR-TB percentage among new TB infections over the 30-year period compared with the baseline using the standard treatment regimen. The multi-way analysis showed eligibility for short-course treatment and treatment initiation greatly influenced the impacts of short-course treatment regimens on reductions in MDR-TB cases and percentage resistance among new infections. Policies which promote the expansion of short-course regimens and early MDR-TB treatment initiation should be considered along with other interventions to tackle antimicrobial resistance in the region.


2019 ◽  
Author(s):  
John Metcalfe ◽  
Peter Bacchetti ◽  
Ali Esmail ◽  
Andrew Reckers ◽  
David Aguilar ◽  
...  

Abstract Abstract Background Treatment monitoring of multidrug-resistant (MDR) and extensively drug-resistant tuberculosis (XDR-TB) in resource-limited settings is challenging. We developed a multi-analyte assay for eleven anti-TB drugs in small hair samples as an objective metric of drug exposure. Methods Small hair samples were collected from participants at various timepoints during directly-observed MDR/XDR-TB treatment at an inpatient tertiary referral facility in South Africa (DR-TB cohort). We assessed an LC-MS/MS index panel assay including isoniazid, ethambutol, pyrazinamide, levofloxacin, moxifloxacin, ethionamide, prothionamide, linezolid, clofazimine, pretomanid, and bedaquiline against a reference standard of inpatient treatment records. Because treatment regimens prior to hospitalization were not available, we also analyzed specificity (for all drugs except isoniazid) using an external cohort of HIV-positive patients treated for latent TB infection with daily isoniazid (HIV/LTBI cohort) in Uganda. Results Among the 57 DR-TB patients (58% with pre-XDR/XDR-TB; 70% HIV-positive) contributing analyzable hair samples, the sensitivity of the investigational assay was 94% or higher for all drugs except ethionamide (58.5%, 95% confidence interval [CI], 40.7-99.9). Assay specificity was low across all tested analytes within the DR-TB cohort; conversely, assay specificity was 100% for all drugs in the HIV/LTBI cohort. Conclusions We developed an 11-drug panel assay to quantitatively ascertain drug exposure within second- and third-line DR-TB treatment regimens. Because hair concentrations reflect long-term exposure, multiple successive regimens commonly employed in DR-TB treatment may result in apparent false-positive qualitative and falsely elevated quantitative hair drug levels when prior treatment histories are not known.


F1000Research ◽  
2020 ◽  
Vol 8 ◽  
pp. 498
Author(s):  
Priya Rathi ◽  
Kalpita Shringarpure ◽  
Bhaskaran Unnikrishnan ◽  
Abhinav Pandey ◽  
Abhirami Nair

Background: Delays in initiating multidrug-resistant tuberculosis (MDR TB) treatment adds risk to individual patients and the community due to disease progression, and on-going transmission. The Government of India offers free TB diagnosis and treatment, however many presumptive MDR TB patients wander within the Indian healthcare system and delay accessing the programme. To improve access to care, it is imperative to understand the treatment pathways taken by MDR TB patients. We aimed to describe the diagnostic and treatment pathway taken by presumptive MDR TB patients registered under Programmatic Management of Drug-resistant TB Program. Methods: We conducted a cross-sectional study amongst patients registered during August 2016 – April 2017 at one District Drug Resistance Tuberculosis centre of Dakshina Kannada district in Karnataka, India. A semi-structured questionnaire was used to collect the number, type (private and public sector), and dates of healthcare facilities (HCFs) visits prior to the initiation of MDR TB treatment. Delays in pathway were measured in days and summarised as median and interquartile range (IQR), from the date of onset of illness until the initiation of MDR TB treatment. Results: We found that patients preferred private HCFs; however, due to lack of treatment and unaffordability they shifted to public HCFs. Median delay to register under the program was more in private HCFs (180 days) in comparison with public HCFs (120 days). We also found that the detection rates were much higher in public HCFs (80%). Conclusion: The present study found that there was substantial patient delay and total delay in diagnosis and treatment of MDR TB patients. Private HCF was first point of contact for most of the patients; however the diagnostic rate was high in public HCF. The government should involve private HCFs to provide standard diagnostics and treatment to the patients seeking a private facility.


PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0255357
Author(s):  
Nguyen Bao Ngoc ◽  
Hoa Vu Dinh ◽  
Nguyen Thi Thuy ◽  
Duong Van Quang ◽  
Cao Thi Thu Huyen ◽  
...  

Objective Management of multidrug-resistant tuberculosis (MDR-TB) is a significant challenge to the global healthcare system due to the complexity and long duration of the MDR-TB treatment. This study analyzed the safety of patients on longer injectable-based MDR-TB treatment regimens using active pharmacovigilance data. Method We conducted an observational, prospective study based on active pharmacovigilance within the national TB program. A total of 659 MDR-TB patients were enrolled and followed up at 9 TB- hospitals in 9 provinces of all 3 regions in Vietnam between 2014 and 2016. Patients received a treatment regimen (standardized or individualized) based on their drug susceptibility test result and their treatment history. Baseline and follow-up information was collected at the start and during treatment. Adverse events (AE) were defined and classified as serious adverse events (SAEs) or otherwise. Multivariate Cox regression following the Iterative Bayesian Model Averaging algorithm was performed to identify factors associated with AE occurrence. Results Out of 659 patients assessed, 71.3% experienced at least one AE, and 17.5% suffered at least one SAE. The most common AEs were gastrointestinal disorders (38.5%), arthralgia (34.7%), and psychiatric disorders (30.0%). The proportion of patients with nephrotoxicity and hearing loss or vestibular disorders were 7.4% and 15.2%, respectively. 13.1% of patients required modifications or interruption of one or more drugs. In 77.7% of patients, treatment was completed successfully, while 9.3% lost to follow-up, in 3.0% treatment failed, and 7.4% died. Some significant risk factors for nephrotoxicity included diabetes mellitus (HR = 8.46 [1.91–37.42]), renal dysfunction (HR = 8.46 [1.91–37.42]), alcoholism (HR = 13.28 [5.04–34.99]), and a higher average daily dose of injectable drugs (HR = 1.28 [1.14–1.43]). Conclusion While a majority of patients on the longer injectable-based regimens experienced non-serious AEs during MDR-TB treatment, one in six patients experienced at least an SAE. Active TB drug-safety monitoring is useful to understand the safety of MDR-TB treatment and explore the risk factors for toxicity. All-oral, shorter MDR-TB regimens might be able to reduce the inconvenience, discomfort, and toxicity of such regimens and increase adherence and likelihood of successful completion.


2019 ◽  
Vol 23 (10) ◽  
pp. 1068-1074 ◽  
Author(s):  
R. Court ◽  
M. T. Chirehwa ◽  
L. Wiesner ◽  
N. de Vries ◽  
J. Harding ◽  
...  

SETTING: Treatment outcomes in multidrug-resistant tuberculosis (MDR-TB) are poor. Due to drug toxicity and a long treatment duration, approximately half of patients are treated successfully. Medication is often crushed for patients who have difficulty swallowing whole tablets. Whether crushing tablets affects drug exposure in MDR-TB treatment is not known.OBJECTIVE AND DESIGN: We performed a sequential pharmacokinetic study in patients aged >18 years on MDR-TB treatment at two hospitals in Cape Town, South Africa. We compared the bioavailability of pyrazinamide, moxifloxacin, isoniazid (INH), ethambutol and terizidone when the tablets were crushed and mixed with water before administration vs. swallowed whole. We sampled blood at six time points over 10 h under each condition separated by 2 weeks. Non-compartmental analysis was used to derive the key pharmacokinetic measurements.RESULTS: Twenty participants completed the study: 15 were men, and the median age was 31.5 years. There was a 42% reduction in the area under the curve AUC0–10 of INH when the tablets were crushed compared with whole tablets (geometric mean ratio 58%; 90%CI 47–73). Crushing tablets of pyrazinamide, moxifloxacin, ethambutol and terizidone did not affect the bioavailability significantly.CONCLUSION: We recommend that crushing of INH tablets in the MDR-TB treatment regimen be avoided. Paediatric INH formulations may be a viable alternative if the crushing of INH tablets is indicated.


2015 ◽  
Vol 59 (10) ◽  
pp. 6073-6079 ◽  
Author(s):  
Anthony J. Garcia-Prats ◽  
Heather R. Draper ◽  
Stephanie Thee ◽  
Kelly E. Dooley ◽  
Helen M. McIlleron ◽  
...  

ABSTRACTOfloxacin is widely used for the treatment of multidrug-resistant tuberculosis (MDR-TB). Data on its pharmacokinetics and safety in children are limited. It is not known whether the current internationally recommended pediatric dosage of 15 to 20 mg/kg of body weight achieves exposures reached in adults with tuberculosis after a standard 800-mg dose (adult median area under the concentration-time curve from 0 to 24 h [AUC0–24], 103 μg · h/ml). We assessed the pharmacokinetics and safety of ofloxacin in children <15 years old routinely receiving ofloxacin for MDR-TB treatment or preventive therapy. Plasma samples were collected predose and at 1, 2, 4, 8, and either 6 or 11 h after a 20-mg/kg dose. Pharmacokinetic parameters were calculated using noncompartmental analysis. Children with MDR-TB disease underwent long-term safety monitoring. Of 85 children (median age, 3.4 years), 11 (13%) were HIV infected, and of 79 children with evaluable data, 14 (18%) were underweight. The ofloxacin mean (range) maximum concentration (Cmax), AUC0–8, and half-life were 8.97 μg/ml (2.47 to 14.4), 44.2 μg · h/ml (12.1 to 75.8), and 3.49 h (1.89 to 6.95), respectively. The mean AUC0–24, estimated in 72 participants, was 66.7 μg · h/ml (range, 18.8 to 120.7). In multivariable analysis, AUC0–24was increased by 1.46 μg · h/ml for each 1-kg increase in body weight (95% confidence interval [CI], 0.44 to 2.47;P= 0.006); no other assessed variable contributed to the model. No grade 3 or 4 events at least possibly attributed to ofloxacin were observed. Ofloxacin was safe and well tolerated in children with MDR-TB, but exposures were well below reported adult values, suggesting that dosage modification may be required to optimize MDR-TB treatment regimens in children.


2017 ◽  
Vol 61 (6) ◽  
Author(s):  
Jian Xu ◽  
Bin Wang ◽  
Minghao Hu ◽  
Fengmin Huo ◽  
Shaochen Guo ◽  
...  

ABSTRACT Clofazimine has been repurposed for the treatment of tuberculosis, especially for multidrug-resistant tuberculosis (MDR-TB). To test the susceptibility to clofazimine of Mycobacterium tuberculosis clinical isolates, MICs of clofazimine were determined using the microplate alamarBlue assay (MABA) method for 80 drug-resistant isolates and 10 drug-susceptible isolates for comparison. For five clofazimine-resistant strains isolated from previously treated pre-extensively drug-resistant TB (pre-XDR-TB) and XDR-TB patients without prior exposure to clofazimine or bedaquiline, clofazimine MICs were ≥1.2 μg/ml. Four isolates with cross-resistance to bedaquiline had Rv0678 mutations. The other isolate with no resistance to bedaquiline had an Rv1979c mutation. This study adds to a recent study showing that 6.3% of MDR-TB patients without prior clofazimine or bedaquiline exposure harbored isolates with Rv0678 mutations, which raises concern that preexisting resistance to these drugs may be associated with prior TB treatment. Furthermore, we propose a tentative breakpoint of 1.2 μg/ml for clofazimine resistance using the MABA method. More-widespread surveillance and individualized testing for clofazimine and bedaquiline resistance, together with assessment of their clinical usage, especially among previously treated and MDR-TB patients, are warranted.


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