Generic Rifater tablets

Background: Tuberculosis remains a leading cause of infectious disease mortality, with over 10 million new cases annually. The standard first-line regimen—isoniazid, rifampicin, pyrazinamide, and ethambutol—has dramatically improved survival, yet drug-induced micronutrient depletion, particularly zinc, is an underappreciated complication that may contribute to treatment-related morbidity. Ethambutol-induced optic neuropathy (EON) affects 1–5% of treated patients, and accumulating evidence implicates zinc chelation as its central mechanism. We hypothesize that anti-TB therapy creates a “multi-hit” zinc depletion state through convergent drug- and disease-mediated pathways.Methods: We conducted a systematic search of PubMed, Scopus, Web of Science, and Cochrane databases from 1944 (discovery of streptomycin) through March 2026. Search terms combined anti-TB drug names with zinc, copper, micronutrient, optic neuropathy, and visual loss. We included randomized controlled trials, cohort studies, case-control studies, case series, in vitro investigations, and animal models. PRISMA 2020 guidelines were followed. Risk of bias was assessed using the Newcastle–Ottawa Scale for observational studies and the Cochrane RoB 2.0 tool for trials.Results: From 2,847 initial records, 186 studies met inclusion criteria. Serum zinc was significantly lower in TB patients versus controls (pooled mean difference: −12.1 μmol/L; 95% CI: −14.5 to −9.7; I² = 68%). Ethambutol directly chelates zinc and copper in retinal ganglion cells via its metabolite EDBA, causing lysosomal membrane permeabilization and mitochondrial dysfunction. Isoniazid depletes pyridoxine, impairing zinc-dependent enzymatic cascades. Rifampicin induces CYP3A4 via PXR activation, accelerating retinol catabolism and functionally coupling zinc deficiency to vitamin A insufficiency through impaired retinol-binding protein synthesis. The zinc–vitamin A axis demonstrates a strong positive correlation (r = 0.86, p < 0.01) in TB cohorts. Zinc supplementation (50 mg elemental zinc/day) improved sputum conversion rates and reduced hepatotoxicity markers in three randomized trials.Conclusions: Anti-TB drugs collectively create a “multi-hit” zinc depletion syndrome that extends beyond simple ethambutol chelation. We propose a clinical algorithm for baseline zinc assessment, risk stratification, and prophylactic supplementation during TB therapy. Persistent visual loss despite ethambutol discontinuation should prompt evaluation of concurrent zinc depletion from isoniazid, rifampicin, and the underlying TB disease itself.

Abstract licence: CC BY

We describe the development and validation of a new high performance liquid chromatography (HPLC) method for analysis of a combination of the first-line anti-tubercular drugs isoniazid, pyrazinamide, and rifampicin together with clofazimine. This is a unique challenge since clofazimine and rifampicin are relatively highly lipophilic drugs, whereas isoniazid and pyrazinamide are considerably more hydrophilic. Thus, clear separation of peaks and quantification of four individual drugs can present difficulties during the development of an analytical method. Detection was established at two wavelengths—254 nm for isoniazid and pyrazinamide and 320 nm for clofazimine and rifampicin. Gradient elution was employed using 0.1% aqueous formic acid (A) and acetonitrile (B); clear separation of the four drugs was achieved within 10 min. A linear relationship was indicated by a correlation coefficient (r2) of 0.9999 for each anti-tubercular drug, respectively. The limit of detection (LOD) for the individual drugs was 0.70 µg/mL (isoniazid), 0.30 µg/mL (pyrazinamide), 0.20 µg/mL (rifampicin) and 0.20 µg/mL (clofazimine). Precision experiments rendered a mean recovery percentage of 101.25% (isoniazid), 98.70% (pyrazinamide), 99.68% (rifampicin) and 97.14% (clofazimine). This HPLC method was validated and is reliable, repeatable, and accurate for the purpose of conducting simultaneous HPLC analyses of the four anti-tubercular drugs.

Abstract licence: CC BY

BACKGROUND: To evaluate the effect of metformin on the plasma levels of rifampicin, isoniazid, and pyrazinamide in patients with drug-sensitive pulmonary tuberculosis being treated with first-line antituberculosis treatment (ATT) and to assess the influence of gene polymorphisms on the metabolic pathway of metformin and plasma levels of antitubercular drugs. METHODS: Nondiabetic adults aged 18-60 years with pulmonary tuberculosis were randomized to either the standard ATT (ATT group) or ATT plus metformin (METRIF group) groups in a phase IIB clinical trial. An intensive pharmacokinetic study with blood collection at 0 hour (predosing), followed by 1, 2, 4, 6, 8, and 12 hours after dosing was conducted during the first month of treatment in a subset of 60 study participants after a minimum of 14 doses. Plasma concentrations of rifampicin, isoniazid, pyrazinamide, and metformin were measured by high-performance liquid chromatography using validated methods, and pharmacokinetic parameters and OCT1 and MATE1 gene polymorphisms were compared between the groups. RESULTS: Significant increases in the clearance of rifampicin, isoniazid, and pyrazinamide were observed in patients in the METRIF group (n = 29) compared with those in the ATT group (n = 31). The AA genotypes of the single-nucleotide polymorphism of rs2289669 ( MATE1 ) in the METRIF group showed a significantly decreased area under the concentration-time curve to the last observation point and increased clearance of rifampicin. CONCLUSIONS: Metformin altered rifampicin and isoniazid plasma concentrations in patients receiving antituberculosis treatment for pulmonary tuberculosis with little effect on sputum conversion at the end of treatment. Studies with larger sample sizes are needed to understand host drug-drug interactions.

Abstract licence: CC BY-NC-ND

Background & objectives: The National Tuberculosis (TB) Control Programme has transitioned from thrice-weekly to daily drug treatment regimens in India. This preliminary study was conceived to compare the pharmacokinetics of rifampicin (RMP), isoniazid (INH) and pyrazinamide (PZA) in TB patients being treated with daily and thrice weekly anti-TB treatment (ATT). Methods: This prospective observational study was undertaken in 49 newly diagnosed adult TB patients receiving either daily ATT (n=22) or thrice-weekly ATT (n=27). Plasma RMP, INH and PZA were estimated by high-performance liquid chromatography. Results: The peak concentration (C max ) of RMP was significantly higher (RMP: 8.5 µg/ml vs . 5.5 µg/ml; P =0.003) and C max of INH was significantly lower (INH: 4.8 µg/ml vs . 10.9 µg/ml; P <0.001) in case of daily dosing compared to thrice-weekly ATT. C max of drugs and doses was significantly correlated. A higher proportion of patients had subtherapeutic RMP C max (8.0 µg/ml) during thrice-weekly compared to daily ATT (78% vs . 36%; P =0.004). Multiple linear regression analysis showed that C max of RMP was significantly influenced by the dosing rhythm, pulmonary TB and C max of INH and PZA by the mg/kg doses. Interpretation & conclusions: RMP concentrations were higher and INH concentrations were lower during daily ATT, suggesting that INH doses may need to be increased in case of a daily regimen. Larger studies are, however, required using higher INH doses when monitoring for adverse drug reactions and treatment outcomes.

Abstract licence: CC BY-NC-SA

. The misuse of antibiotics has led to the development of drug resistance, prompting researchers to explore new technologies to combat multidrug-resistant Tuberculosis (MDR TB). Phospholipid-based nanotherapeutics, such as nanoemulsions, are gaining traction as they enhance drug solubility, stability, and bioavailability. Our study focuses on the interaction between Bovine Serum Albumin (BSA) and a drug-loaded nanoemulsion based on Eugenol. This nanoemulsion incorporates Eugenol, Clove, cinnamon oil, and first-line anti-tuberculosis drugs like Rifampicin, Isoniazid, Pyrazinamide, and Ethambutol. The primary objective is to assess the biosafety profile of the nanoemulsion upon interaction with BSA. We employed Fluorescence, UV-visible, and Fourier Transform Infrared Spectroscopy (FTIR) to analyze this interaction. UV-visible spectroscopy detected changes in hydrophobicity due to structural alterations in BSA near the tryptophan residue, leading to the formation of ground-state complexes. Fluorescence spectroscopy demonstrated that the nanoemulsion effectively quenched fluorescence originating from tryptophan and tyrosine residues. Studies using synchronous and three-dimensional spectroscopy point to a potential modification of the aromatic environment of BSA by the nanoemulsion. Resonance light scattering spectra indicated the formation of large aggregates due to the interaction with the nanoemulsion. The second derivative FTIR spectra showed an increase in the magnitude of secondary structure bands, suggesting a conformational shift. This research has significant pharmacological implications for developing safer, more targeted drug delivery systems. The information obtained from the interaction of the nanoemulsion with the blood carrier protein is vital for the future development of superior carriers with minimal adverse effects on patients. It is crucial to remember that conformational changes brought on by drug-ligand complexes attaching to carrier proteins may have negative consequences. Therefore, this study enhances the in vitro evaluation of potential adverse effects of the nanoemulsion on serum proteins.

Abstract licence: CC BY-NC-ND