Pharmacokinetics and pharmacodynamics of high-dose isoniazid for the treatment of rifampicin- or multidrug-resistant tuberculosis in Indonesia.

BACKGROUND: Pharmacokinetic data on high-dose isoniazid for the treatment of rifampicin-/multidrug-resistant tuberculosis (RR/MDR-TB) are limited. We aimed to describe the pharmacokinetics of high-dose isoniazid, estimate exposure target attainment, identify predictors of exposures, and explore exposure-response relationships in RR/MDR-TB patients. METHODS: We performed an observational pharmacokinetic study, with exploratory pharmacokinetic/pharmacodynamic analyses, in Indonesian adults aged 18-65 years treated for pulmonary RR/MDR-TB with standardized regimens containing high-dose isoniazid (10-15 mg/kg/day) for 9-11 months. Intensive pharmacokinetic sampling was performed after ≥2 weeks of treatment. Total plasma drug exposure (AUC0-24) and peak concentration (Cmax) were assessed using non-compartmental analyses. AUC0-24/MIC ratio of 85 and Cmax/MIC ratio of 17.5 were used as exposure targets. Multivariable linear and logistic regression analyses were used to identify predictors of drug exposures and responses, respectively. RESULTS: We consecutively enrolled 40 patients (median age 37.5 years). The geometric mean isoniazid AUC0-24 and Cmax were 35.4 h·mg/L and 8.5 mg/L, respectively. Lower AUC0-24 and Cmax values were associated (P < 0.05) with non-slow acetylator phenotype, and lower Cmax values were associated with male sex. Of the 26 patients with MIC data, less than 25% achieved the proposed targets for isoniazid AUC0-24/MIC (n = 6/26) and Cmax/MIC (n = 5/26). Lower isoniazid AUC0-24 values were associated with delayed sputum culture conversion (>2 months of treatment) [adjusted OR 0.18 (95% CI 0.04-0.89)]. CONCLUSIONS: Isoniazid exposures below targets were observed in most patients, and certain risk groups for low isoniazid exposures may require dose adjustment. The effect of low isoniazid exposures on delayed culture conversion deserves attention.

Global estimates and determinants of antituberculosis drug pharmacokinetics in children and adolescents: a systematic review and individual patient data meta-analysis.

BACKGROUND: Suboptimal exposure to antituberculosis (anti-TB) drugs has been associated with unfavourable treatment outcomes. We aimed to investigate estimates and determinants of first-line anti-TB drug pharmacokinetics in children and adolescents at a global level. METHODS: We systematically searched MEDLINE, Embase and Web of Science (1990-2021) for pharmacokinetic studies of first-line anti-TB drugs in children and adolescents. Individual patient data were obtained from authors of eligible studies. Summary estimates of total/extrapolated area under the plasma concentration-time curve from 0 to 24 h post-dose (AUC0-24) and peak plasma concentration (C max) were assessed with random-effects models, normalised with current World Health Organization-recommended paediatric doses. Determinants of AUC0-24 and C max were assessed with linear mixed-effects models. RESULTS: Of 55 eligible studies, individual patient data were available for 39 (71%), including 1628 participants from 12 countries. Geometric means of steady-state AUC0-24 were summarised for isoniazid (18.7 (95% CI 15.5-22.6) h·mg·L-1), rifampicin (34.4 (95% CI 29.4-40.3) h·mg·L-1), pyrazinamide (375.0 (95% CI 339.9-413.7) h·mg·L-1) and ethambutol (8.0 (95% CI 6.4-10.0) h·mg·L-1). Our multivariate models indicated that younger age (especially <2 years) and HIV-positive status were associated with lower AUC0-24 for all first-line anti-TB drugs, while severe malnutrition was associated with lower AUC0-24 for isoniazid and pyrazinamide. N-acetyltransferase 2 rapid acetylators had lower isoniazid AUC0-24 and slow acetylators had higher isoniazid AUC0-24 than intermediate acetylators. Determinants of C max were generally similar to those for AUC0-24. CONCLUSIONS: This study provides the most comprehensive estimates of plasma exposures to first-line anti-TB drugs in children and adolescents. Key determinants of drug exposures were identified. These may be relevant for population-specific dose adjustment or individualised therapeutic drug monitoring.

Treatment Outcomes of Childhood Tuberculous Meningitis in a Real-World Retrospective Cohort, Bandung, Indonesia.

We retrospectively evaluated clinical features and outcomes in children treated for tuberculous meningitis (TBM) at Hasan Sadikin Hospital, Bandung, Indonesia, during 2011-2020. Among 283 patients, 153 (54.1%) were <5 years of age, and 226 (79.9%) had stage II or III TBM. Predictors of in-hospital death (n = 44 [15.5%]) were stage III TBM, hydrocephalus, male sex, low-income parents, seizures at admission, and lack of bacillus Calmette-Guérin vaccination. Predictors of postdischarge death (n = 18 [6.4%]) were hydrocephalus, tuberculoma, and lack of bacillus Calmette-Guérin vaccination. At treatment completion, 91 (32.1%) patients were documented to have survived, of whom 33 (36.3%) had severe neurologic sequelae and 118 (41.7%) had unknown outcomes. Predictors of severe neurologic sequelae were baseline temperature >38°C, stage III TBM, and baseline motor deficit. Despite treatment, childhood TBM in Indonesia causes substantial neurologic sequelae and death, highlighting the importance of improved early diagnosis, better tuberculosis prevention, and optimized TBM management strategies.

Towards elimination of childhood and adolescent tuberculosis in the Netherlands: an epidemiological time-series analysis of national surveillance data.

BACKGROUND: Tuberculosis (TB) in children and adolescents is a sentinel event for ongoing transmission. In the Netherlands, epidemiological characteristics of childhood and adolescent TB have not been fully evaluated. Therefore, we aimed to assess TB epidemiology within this population to provide guidance for TB elimination. METHODS: A retrospective time-series analysis using national surveillance data from 1993-2018 was performed in children (aged <15 years) and adolescents (aged 15-19 years) with TB. Poisson regression models offset with log-population size were used to estimate notification rates and rate ratios. Trends in notification rates were estimated using average annual percentage changes (AAPC) based on the segmented linear regression analysis. RESULTS: Among 3899 children and adolescents with TB notified during 1993-2018, 2418 (62%) were foreign-born (725 (41.3%) out of 1755 children and 1693 (78.9%) out of 2144 adolescents). The overall notification rate in children was 2.3 per 100 000 person-years, declining steadily during the study period (AAPC -10.9%, 95% CI -12.6--9.1). In adolescents, the overall notification rate was 8.4 per 100 000 person-years, strongly increasing during 1993-2001 and 2012-2018. Compared to Dutch-born children and adolescents, substantially higher notification rates were observed among African-born children and adolescents (116.8 and 316.6 per 100 000 person-years, respectively). Additionally, an increasing trend was observed in African-born adolescents (AAPC 18.5%, 95% CI 11.9-25.5). Among the foreign-born population, those from countries in the horn of Africa contributed most to the TB caseload. CONCLUSION: TB notification rate among children was low and constantly declining across different demographic groups. However, heterogeneities were shown in adolescents, with an increasing trend in the foreign-born, particularly those from Africa.

Nationwide analysis of treatment outcomes in children and adolescents routinely treated for tuberculosis in the Netherlands.

BACKGROUND: As a vulnerable population, children and adolescents with tuberculosis (TB) are faced with many challenges, even those who live in low TB incidence countries. We aimed to evaluate factors associated with TB treatment outcomes allowing more focused interventions to support this population once diagnosed. METHODS: A retrospective cohort study using a nationwide surveillance database was performed in children and adolescents (aged 0-18 years) treated for TB in the Netherlands from 1993 to 2018. Logistic regression analyses were used to estimate adjusted odds ratios (aOR) for associated factors of mortality and loss to follow-up (LTFU). RESULTS: Among 3253 eligible patients with known outcomes, 94.4% (95.9% children and 92.8% adolescents) were cured or completed treatment, 0.7% died during treatment and 4.9% were LTFU. There were no reported treatment failures. Risk factors of death included children aged 2-4 years (aOR 10.42), central nervous system TB (aOR 5.14), miliary TB (aOR 10.25), HIV co-infection (aOR 8.60), re-treated TB cases (aOR 10.12) and drug-induced liver injury (aOR 6.50). Active case-finding was a protective factor of death (aOR 0.13). Risk factors of LTFU were adolescents aged 15-18 years (aOR 1.91), illegal immigrants (aOR 4.28), urban domicile (aOR 1.59), unknown history of TB contact (aOR 1.99), drug-resistant TB (aOR 2.31), single adverse drug reaction (aOR 2.12), multiple adverse drug reactions (aOR 7.84) and treatment interruption >14 days (aOR 6.93). Treatment in recent years (aOR 0.94) and supervision by public health nurses (aOR 0.14) were protective factors of LTFU. CONCLUSION: Highly successful treatment outcomes were demonstrated in children and adolescents routinely treated for TB. Special attention should be given to specific risk groups to improve treatment outcomes.

Predictors of clinical response to extrafine and non-extrafine particle inhaled corticosteroids in smokers and ex-smokers with asthma.

We performed a post-hoc analysis of the OLiVIA-study investigating whether current and ex-smoking asthmatics with small airways dysfunction (SAD) show a better response in airway hyperresponsiveness (AHR) to small particle adenosine after treatment with extrafine compared to non-extrafine particle inhaled corticosteroids (ICS), and to investigate which clinical parameters predict a favorable response to both treatments. We show that smoking and ex-smoking asthmatics with and without SAD have a similar treatment response with either extrafine or non-extrafine particle ICS. We also found that lower blood neutrophils are associated with a smaller ICS-response in smokers and ex-smokers with asthma, independent from the level of blood eosinophils.

Pharmacokinetics of standard versus high-dose rifampin for tuberculosis preventive treatment: A sub-study of the 2R2 randomized controlled trial.

BACKGROUND: Pharmacokinetic data of rifampin, when used for tuberculosis preventive treatment (TPT) are not available. We aimed to describe the pharmacokinetics of rifampin used for TPT, at standard and higher doses, and to assess predictors of rifampin exposure. METHODS: A pharmacokinetic sub-study was performed in Bandung, Indonesia among participants in the 2R2 randomized trial, which compared TPT regimens of 2 months of high-dose rifampin at 20 mg/kg/day (2R20) and 30 mg/kg/day (2R30), with 4 months of standard-dose rifampin at 10 mg/kg/day (4R10) in adolescents and adults. Intensive pharmacokinetic sampling was performed after 2-8 weeks of treatment. Pharmacokinetic parameters were assessed non-compartmentally. Total exposure (AUC0-24) and peak concentration (Cmax) between arms were compared using one-way ANOVA and Tukey's post-hoc tests. Multivariable linear regression analyses were used to assess predictors of AUC0-24 and Cmax. RESULTS: We enrolled 51 participants in this study. In the 4R10, 2R20, and 2R30 arms, the geometric mean AUC0-24 was 68.0, 186.8, and 289.9 h⋅mg/L, and Cmax was 18.4, 36.7, and 54.4 mg/L, respectively; high interindividual variabilities were observed. Compared with the 4R10 arm, AUC0-24 and Cmax were significantly higher in the 2R20 and 2R30 arms (P < 0.001). Drug doses, body weight, and female sex were predictors of higher rifampin AUC0-24 and Cmax (P < 0.05). AUC0-24 and Cmax values were much higher than those previously reported in persons with TB disease. CONCLUSIONS: Doubling and tripling the rifampin dose led to three- and four-fold higher exposure compared to standard dose. Pharmacokinetic/pharmacodynamic modelling and simulations are warranted to support trials of shortening the duration of TPT regimens with high-dose rifampin.

Pharmacokinetics and safety/tolerability of isoniazid, rifampicin and pyrazinamide in children and adolescents treated for tuberculous meningitis.

OBJECTIVE: To assess the pharmacokinetics and safety/tolerability of isoniazid, rifampicin and pyrazinamide in children and adolescents with tuberculous meningitis (TBM). DESIGN: Prospective observational pharmacokinetic study with an exploratory pharmacokinetic/pharmacodynamic analysis. SETTING: Hasan Sadikin Hospital, Bandung, Indonesia. PATIENTS: Individuals aged 0-18 years clinically diagnosed with TBM and receiving first-line anti-tuberculosis drug dosages according to revised WHO-recommended treatment guidelines. INTERVENTIONS: Plasma and cerebrospinal fluid (CSF) concentrations of isoniazid, rifampicin and pyrazinamide were assessed on days 2 and 10 of treatment. MAIN OUTCOME MEASURES: Plasma exposures during the daily dosing interval (AUC0-24), peak plasma concentrations (Cmax) and CSF concentrations. RESULTS: Among 20 eligible patients, geometric mean AUC0-24 of isoniazid, rifampicin and pyrazinamide was 18.5, 66.9 and 315.5 hour∙mg/L on day 2; and 14.5, 71.8 and 328.4 hour∙mg/L on day 10, respectively. Large interindividual variabilities were observed in AUC0-24 and Cmax of all drugs. All patients had suboptimal rifampicin AUC0-24 for TBM treatment indication and very low rifampicin CSF concentrations. Four patients developed grade 2-3 drug-induced liver injury (DILI) within the first 4 weeks of treatment, in whom anti-tuberculosis drugs were temporarily stopped, and no DILI recurred after reintroduction of rifampicin and isoniazid. AUC0-24 of isoniazid, rifampicin and pyrazinamide along with Cmax of isoniazid and pyrazinamide on day 10 were higher in patients who developed DILI than those without DILI (p<0.05). CONCLUSION: Higher rifampicin doses are strongly warranted in treatment of children and adolescents with TBM. The association between higher plasma concentrations of isoniazid, rifampicin and pyrazinamide and the development of DILI needs confirmatory studies.

Antituberculosis Drug-induced Liver Injury in Children: Incidence and Risk Factors During the Two-month Intensive Phase of Therapy.

BACKGROUND: As one of the most frequent and serious adverse reactions during tuberculosis (TB) treatment, antituberculosis drug-induced liver injury (ATLI) in children has been studied insufficiently compared with adults. We aimed to determine the incidence and risk factors of ATLI in children during the first 2 months of TB therapy. METHODS: A total of 41 children with TB and treated with first-line anti-TB drugs were prospectively followed-up for the development of ATLI. Liver function tests were performed at baseline and after 2 weeks of therapy. Subsequent tests were conducted at 4, 6 and 8 weeks if the initial 2-week measurement was abnormal or if symptoms of hepatotoxicity were reported. RESULTS: ATLI was detected in 11 (27%) patients within 14 to 42 days from the start of therapy, with most of them (54%) occurred after 2 weeks. TB treatment was stopped immediately in 6 of 11 patients who developed ATLI, and no recurrent hepatotoxicity after drug reintroductions in these patients. Univariate analysis showed that ATLI was significantly associated with TB meningitis (P < 0.01), hypoalbuminemia (P < 0.05) and hepatotoxic comedications (P < 0.01). Age, sex, nutritional status, HIV status and baseline liver function abnormalities were not associated with ATLI. Multivariate analysis identified hypoalbuminemia and hepatotoxic comedications (both P < 0.1) tend to be independently associated with ATLI. CONCLUSIONS: Children with hypoalbuminemia and use of hepatotoxic comedications are suggested to be monitored closely for the development of ATLI.