| 1. |
- Cresswell, Fiona, V, et al.
(författare)
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High-Dose Oral and Intravenous Rifampicin for the Treatment of Tuberculous Meningitis in Predominantly Human Immunodeficiency Virus (HIV)-Positive Ugandan Adults : A Phase II Open-Label Randomized Controlled Trial
- 2021
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Ingår i: Clinical Infectious Diseases. - : Oxford University Press. - 1058-4838 .- 1537-6591. ; 73:5, s. 876-884
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Tidskriftsartikel (refereegranskat)abstract
- Background: High-dose rifampicin may improve outcomes of tuberculous meningitis (TBM). Little safety or pharmacokinetic (PK) data exist on high-dose rifampicin in human immunodeficiency virus (HIV) coinfection, and no cerebrospinal fluid (CSF) PK data exist from Africa. We hypothesized that high-dose rifampicin would increase serum and CSF concentrations without excess toxicity. Methods: In this phase II open-label trial, Ugandan adults with suspected TBM were randomized to standard-of-care control (PO-10, rifampicin 10 mg/kg/day), intravenous rifampicin (IV-20, 20 mg/kg/day), or high-dose oral rifampicin (PO-35, 35 mg/kg/day). We performed PK sampling on days 2 and 14. The primary outcomes were total exposure (AUC(0-24)), maximum concentration (C-max), CSF concentration, and grade 3-5 adverse events. Results: We enrolled 61 adults, 92% were living with HIV, median CD4 count was 50 cells/mu L (interquartile range [IQR] 46-56). On day 2, geometric mean plasma AUC(0-24hr) was 42.9.h mg/L with standard-of-care 10 mg/kg dosing, 249.h mg/L for IV-20 and 327.h mg/L for PO-35 (P<.001). In CSF, standard of care achieved undetectable rifampicin concentration in 56% of participants and geometric mean AUC(0-24hr) 0.27 mg/L, compared with 1.74 mg/L (95% confidence interval [CI] 1.2-2.5) for IV-20 and 2.17 mg/L (1.6-2.9) for PO-35 regimens (P<.001). Achieving CSF concentrations above rifampicin minimal inhibitory concentration (MIC) occurred in 11% (2/18) of standard-of-care, 93% (14/15) of IV-20, and 95% (18/19) of PO-35 participants. Higher serum and CSF levels were sustained at day 14. Adverse events did not differ by dose (P=.34). Conclusions: Current international guidelines result in sub-therapeutic CSF rifampicin concentration for 89% of Ugandan TBM patients. High-dose intravenous and oral rifampicin were safe and respectively resulted in exposures similar to 6- and similar to 8-fold higher than standard of care, and CSF levels above the MIC.
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| 2. |
- Denti, Paolo, et al.
(författare)
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Optimizing Dosing and Fixed-Dose Combinations of Rifampicin, Isoniazid, and Pyrazinamide in Pediatric Patients With Tuberculosis : A Prospective Population Pharmacokinetic Study
- 2022
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Ingår i: Clinical Infectious Diseases. - : OXFORD UNIV PRESS INC. - 1058-4838 .- 1537-6591. ; 75:1, s. 141-151
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Tidskriftsartikel (refereegranskat)abstract
- Background In 2010, the World Health Organization (WHO) revised dosing guidelines for treatment of childhood tuberculosis. Our aim was to investigate first-line antituberculosis drug exposures under these guidelines, explore dose optimization using the current dispersible fixed-dose combination (FDC) tablet of rifampicin/isoniazid/pyrazinamide; 75/50/150 mg, and suggest a new FDC with revised weight bands. Methods Children with drug-susceptible tuberculosis in Malawi and South Africa underwent pharmacokinetic sampling while receiving first-line tuberculosis drugs as single formulations according the 2010 WHO recommended doses. Nonlinear mixed-effects modeling and simulation was used to design the optimal FDC and weight-band dosing strategy for achieving the pharmacokinetic targets based on literature-derived adult AUC(0-24h) for rifampicin (38.7-72.9), isoniazid (11.6-26.3), and pyrazinamide (233-429 mg center dot h/L). Results In total, 180 children (42% female; 13.9% living with human immunodeficiency virus [HIV]; median [range] age 1.9 [0.22-12] years; weight 10.7 [3.20-28.8] kg) were administered 1, 2, 3, or 4 FDC tablets (rifampicin/isoniazid/pyrazinamide 75/50/150 mg) daily for 4-8, 8-12, 12-16, and 16-25 kg weight bands, respectively. Rifampicin exposure (for weight and age) was up to 50% lower than in adults. Increasing the tablet number resulted in adequate rifampicin but relatively high isoniazid and pyrazinamide exposures. Administering 1, 2, 3, or 4 optimized FDC tablets (rifampicin/isoniazid/pyrazinamide 120/35/130 mg) to children < 6, 6-13, 13-20. and 20-25 kg, and 0.5 tablet in < 3-month-olds with immature metabolism, improved exposures to all 3 drugs. Conclusions Current pediatric FDC doses resulted in low rifampicin exposures. Optimal dosing of all drugs cannot be achieved with the current FDCs. We propose a new FDC formulation and revised weight bands. Current pediatric dosing guidelines lead to infant rifampicin exposures much lower than in adults, whereas isoniazid and pyrazinamide exposures are similar. A new fixed-dose combination (FDC) with rifampicin/isoniazid/pyrazinamide 120/35/130 mg and weight bands of < 6, 6-13, 13-20, and 20-25 kg could improve treatment.
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| 3. |
- Susanto, Budi Octasari, et al.
(författare)
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Rifampicin can be given as flat-dosing instead of weight-band dosing
- 2020
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Ingår i: Clinical Infectious Diseases. - : Oxford University Press (OUP). - 1058-4838 .- 1537-6591. ; 71:12, s. 3055-3060
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The weight-band dosing in tuberculosis treatment regimen has been implemented in clinical practice for decades. Patients will receive different number of fixed dose combination (FDC) tablets according to their weight-band. However, some analysis have shown that weight was not the best covariate to explain variability of rifampicin exposure. Furthermore, the rationale for using weight-band dosing instead of flat-dosing becomes questionable. Therefore, this study aimed to compare the average and the variability of rifampicin exposure after weight-band dosing and flat-dosing.METHODS: Rifampicin exposure were simulated using previously published population pharmacokinetics model at dose 10-40 mg/kg for weight-band dosing and dose 600-2400 mg for flat-dosing. The median AUC0-24h after day 7 and 14 were compared as well as the variability of each dose group between weight-band and flat-dosing.RESULTS: The difference of median AUC0-24h of all dose groups between flat-dosing and weight-band dosing were considered low (< 20%) except for the lowest dose. At the dose of 10 mg/kg (600 mg for flat-dosing), flat-dosing resulted in higher median AUC0-24h compared to the weight-band dosing. A marginal decrease in between-patient variability was predicted for weight-band dosing compared to flat-dosing.CONCLUSIONS: Weight-band dosing yields a small and non-clinically relevant decrease in variability of AUC0-24h.
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| 4. |
- Svensson, Elin M., 1985-, et al.
(författare)
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Model-based meta-analysis of rifampicin exposure and mortality in Indonesian tuberculous meningitis trials
- 2020
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Ingår i: Clinical Infectious Diseases. - : Oxford University Press (OUP). - 1058-4838 .- 1537-6591. ; 71:8, s. 1817-1823
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundIntensified antimicrobial treatment with higher rifampicin doses may improve outcome of tuberculous meningitis, but the desirable exposure and necessary dose are unknown. Our objective was to characterize the relationship between rifampicin exposures and mortality in order to identify optimal dosing for tuberculous meningitis.MethodsAn individual patient meta-analysis was performed on data from 3 Indonesian randomized controlled phase 2 trials comparing oral rifampicin 450 mg (~10 mg/kg) to intensified regimens including 750–1350 mg orally, or a 600-mg intravenous infusion. Pharmacokinetic data from plasma and cerebrospinal fluid (CSF) were analyzed with nonlinear mixed-effects modeling. Six-month survival was described with parametric time-to-event models.ResultsPharmacokinetic analyses included 133 individuals (1150 concentration measurements, 170 from CSF). The final model featured 2 disposition compartments, saturable clearance, and autoinduction. Rifampicin CSF concentrations were described by a partition coefficient (5.5%; 95% confidence interval [CI], 4.5%–6.4%) and half-life for distribution plasma to CSF (2.1 hours; 95% CI, 1.3–2.9 hours). Higher CSF protein concentration increased the partition coefficient. Survival of 148 individuals (58 died, 15 dropouts) was well described by an exponentially declining hazard, with lower age, higher baseline Glasgow Coma Scale score, and higher individual rifampicin plasma exposure reducing the hazard. Simulations predicted an increase in 6-month survival from approximately 50% to approximately 70% upon increasing the oral rifampicin dose from 10 to 30 mg/kg, and predicted that even higher doses would further improve survival.ConclusionsHigher rifampicin exposure substantially decreased the risk of death, and the maximal effect was not reached within the studied range. We suggest a rifampicin dose of at least 30 mg/kg to be investigated in phase 3 clinical trials.
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