Simultaneous determination of first-line anti-tuberculosis drugs and one metabolite of isoniazid by liquid chromatography/tandem mass spectrometry in patients with human immunodeficiency virus-tuberculosis coinfection

How to determine the course of preoperative chemotherapy for spinal tuberculosis: A single-center clinical study

This study aims to explore the clinical efficacy and feasibility of preoperative 1-week chemotherapy for patients with spinal tuberculosis (STB) undergoing complete lesion removal. Clinical data of 76 patients with STB who underwent complete focal debridement in our hospital were collected from June 2020 to September 2023. The patients were divided into 38 cases of preoperative 1-week chemotherapy group (Group A) according to the length of preoperative chemotherapy, and 38 cases of preoperative 2 to 4-week chemotherapy group (Group B). Perioperative related, imaging, and laboratory examination indices as well as postoperative neurological function recovery, postoperative pain recovery, related complications, and clinical efficacy were analyzed to compare the clinical efficacy of the 2 groups. All patients successfully completed the treatment of stage I complete lesion removal combined with bone grafting fusion and internal fixation. The difference in erythrocyte setting rate and C-reactive protein at the same postoperative observation time between the 2 groups was not statistically significant (P > .05). The visual analogue scale scores of patients in the 2 groups decreased significantly with prolonged time, and the difference was statistically significant (P < .05). All patients achieved satisfactory clinical efficacy (P < .05). All patients achieved good clinical outcomes, the difference between the groups was not statistically significant (P > .05). The difference in incision healing rate at 3 months postoperatively and bone graft fusion rate at 6 months postoperatively was not statistically significant between the 2 groups (P > .05). The dissemination and recurrence of Mycobacterium tuberculosis were not statistically significantly different between the 2 groups after surgery (P > .05). In summary, with complete lesion clearance, 1 week of preoperative chemotherapy is feasible in patients with STB with varying degrees of neurological dysfunction.

Natural deep eutectic solvent for the simultaneous derivatization and microextraction of isoniazid from human plasma

BACKGROUND

Personalized medicine is a rapidly revolving field that offers new opportunities for tailoring disease treatment to individual patients. The main idea behind this approach is to carefully select safe and effective medications and treatment plant based on each patient's unique pharmacokinetic profile. Isoniazid is a first-line anti-tuberculosis drug that has interindividual variability in its metabolic processing, leading to significant differences in plasma concentrations among patients receiving equivalent doses. This variability necessitates the creation of individualized treatment regimens as part of personalized medicine to achieve more effective therapy.

RESULTS

In this work, a deep eutectic solvent-based liquid-liquid microextraction approach for the separation and determination of isoniazid in human plasma by high-performance liquid chromatography with UV-Vis detection was developed for the first time. A new natural deep eutectic solvent based on thymol as a hydrogen bond donor and 4-methoxybenzaldehyde as a hydrogen bond acceptor was proposed as the extraction solvent. The developed microextraction procedure assumed two simultaneous processes during the mixing of the sample and extraction solvent: the derivatization of the polar analyte in the presence of 4-methoxybenzaldehyde (component of the natural deep eutectic solvent) with the formation of a hydrophobic Schiff base (1); mass transfer of the Schiff base from the sample phase to the extraction solvent phase (2). Under optimal conditions, the limits of detection and quantification were 20 and 60 μg L-1, respectively. The RSD value was <10 %, the extraction recovery was 95 %.

SIGNIFICANCE

In this work, the possibility of isoniazid derivatization in the natural deep eutectic solvent phase with the formation of the Schiff base was presented for the first time. The approach provided the separation and preconcentration of polar isoniazid without the use of expensive derivatization agents and solid-phase extraction cartridges. The formation of the Schiff base was confirmed by mass spectrometry.

Push forward LC-MS-based therapeutic drug monitoring and pharmacometabolomics for anti-tuberculosis precision dosing and comprehensive clinical management

The spread of tuberculosis (TB), especially multidrug-resistant TB and extensively drug-resistant TB, has strongly motivated the research and development of new anti-TB drugs. New strategies to facilitate drug combinations, including pharmacokinetics-guided dose optimization and toxicology studies of first- and second-line anti-TB drugs have also been introduced and recommended. Liquid chromatography-mass spectrometry (LC-MS) has arguably become the gold standard in the analysis of both endo- and exo-genous compounds. This technique has been applied successfully not only for therapeutic drug monitoring (TDM) but also for pharmacometabolomics analysis. TDM improves the effectiveness of treatment, reduces adverse drug reactions, and the likelihood of drug resistance development in TB patients by determining dosage regimens that produce concentrations within the therapeutic target window. Based on TDM, the dose would be optimized individually to achieve favorable outcomes. Pharmacometabolomics is essential in generating and validating hypotheses regarding the metabolism of anti-TB drugs, aiding in the discovery of potential biomarkers for TB diagnostics, treatment monitoring, and outcome evaluation. This article highlighted the current progresses in TDM of anti-TB drugs based on LC-MS bioassay in the last two decades. Besides, we discussed the advantages and disadvantages of this technique in practical use. The pressing need for non-invasive sampling approaches and stability studies of anti-TB drugs was highlighted. Lastly, we provided perspectives on the prospects of combining LC-MS-based TDM and pharmacometabolomics with other advanced strategies (pharmacometrics, drug and vaccine developments, machine learning/artificial intelligence, among others) to encapsulate in an all-inclusive approach to improve treatment outcomes of TB patients.

New approach to rifampicin stability and first-line anti-tubercular drug pharmacokinetics by UPLC-MS/MS

Successful tuberculosis (TB) therapy requires achieving sufficient exposure to multiple drugs. Limited stability of several first-line anti-TB drugs might compromise reliable therapeutic drug monitoring (TDM). We developed and validated a sensitive and selective UPLC-MS/MS method for simultaneous quantification of isoniazid (INH), pyrazinamide (PZA), rifampicin (RIF), its metabolite 25-desacetylrifampicin and degradation products: rifampicin quinone and 3-formyl-rifampicin. Analysis was completed from a very small plasma volume (20 µL) using only protein precipitation with methanol. Chromatographic separation was achieved on a Kinetex Polar C18 column (2.6 µm; 150 × 3 mm) with a mobile phase consisting of 5 mM ammonium acetate and acetonitrile, both containing 0.1 % formic acid, in gradient elution. The analytes were detected using a positive ionization mode by multiple reaction monitoring. The LLOQ for RIF and its degradation products was 0.1 µg/mL, 0.05 µg/mL for INH, and 0.2 µg/mL for PZA. The method was validated based on the FDA guidance. The application of the method was confirmed in the analysis of RIF, INH, and PZA, as well as RIF metabolism/degradation products in plasma samples of patients with TB. Based on the detailed stability study of the analyzed compounds at various storage conditions, we proposed recommendations for handling the plasma and serum samples in TDM and other pharmacokinetic studies.

Chromatographic Methods for the Determination of Rifampicin, Isoniazid, Pyrazinamide, Ethambutol, and Main Metabolites in Biological Samples: A Review

Bioanalytical methods are used to quantify drugs and their metabolites in biological samples in order to determine bioequivalence, perform pharmacokinetic and bioavailability studies, and complete therapeutic drug monitoring. The objective of this review paper is to describe bioanalytical methods based on Liquid Chromatography that are used to quantify antitubercular drugs and their metabolites in different biological samples, utilizing scientific literature from 1992 to 2021.

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.

Pharmacokinetic features of dolutegravir with rifampicin and rifabutin among patients coinfected with human immunodeficiency virus and tuberculosis/mycobacterium avium complex

BACKGROUND

Rifamycins are the cornerstone of anti-tuberculosis therapy while they are potent inducers of drug metabolizing enzymes. For the first time, we evaluated the effect of rifampicin (RIF) and rifabutin (RBT) on the pharmacokinetics (PK) of dolutegravir (DTG) in patients with HIV and tuberculosis (TB)/ mycobacterium avium complex (MAC) co-infection.

METHODS

Both HIV/TB (or MAC) co-infected patients and HIV infected patients without TB/MAC were enrolled. Patients in the RIF group received DTG 50 mg twice daily together with 600mg of RIF, while patients in the RBT group received DTG 50 mg once daily together with 300 mg of RBT. The DTG pharmacokinetic profiles in different groups were assessed.

RESULTS

A total of 13 subjects in the RIF group, 12 subjects in the RBT group, and 10 subjects in non-TB/MAC group were enrolled. The geometric mean ratio (GMR) of the trough concentration (Ctr) of DTG in the RIF group to non-TB/MAC group was 1.33 [90% confidence interval (CI):0.97 to 1.81], while the GMR of the maximum concentration (Cmax) of DTG was 1.29 (90% CI: 1.23 to 1.36). The GMR of the Ctr of DTG in the RBT group to non-TB/MAC group was 0.41 (90% CI: 0.30 to 0.57), while the GMR of the Cmax of DTG was 0.55 (90% CI: 0.52 to 0.57).

CONCLUSIONS

Due to the relatively low trough concentrations of DTG with RBT, DTG 50mg once daily together with RBT could only serve as an alternative option for HIV/TB (or MAC) co-infected patients.